Optimizing BFD Authentication
draft-ietf-bfd-optimizing-authentication-36

[Ballot comment]
Thanks for preparing this I-D, and amending the abstract.
I have the following comments which I hope will help revise this I-D.

### 1. Thank you to Marcus Ihlar for his TSV-ART review, see: https://datatracker.ietf.org/doc/review-ietf-bfd-optimizing-authentication-28-tsvart-lc-ihlar-2025-08-18/

As noted in the reviwe, could the editors please add a short discussion on loss and reauthentication
in Section 5, or in an Operational Considerations section?

### 2. The I-D text ought to say why the document is experimental, please could you add to
  the Introduction by citing the Appendix that explains this.

### 3. The I-D currently states: "All BFD Control Packets with the states AdminDown, Down, and Init
  require strong authentication." - could this be a RFC-2119 requirement?
  Please consider making this a nomative case for this I-D , i.e. make this "REQUIRES",
  or the REQUIRES in the following:
  "In addition to these requirements, BFD "significant changes" require
  strong authentication."

### 5. The I-D currently states:
  "When using the less computationally intensive authentication
  mechanism, BFD should periodically test the session using the strong
  authentication mechanism."
  - I'd agree, but I do think the text needs to explain why this is
  desirable, i.e. to justify why people SHOULD think seriously about
  enabling this test.

### 6. The I-D currently states:
  "Once
  enabled, every packet must have Authentication Bit set and the
  associated Authentication Type appended."
  - Please cit the section here, I could not be sure what was cited?

### 7. The I-D currently states:
  "As a security precaution, it mentions that
  authentication state be allowed to change at most once"
  Whereas, RFC 5880 use RFC-2119 text:
  "In order to avoid security risks, implementations using this method
  SHOULD only allow the authentication state to be changed at most once
  without some form of intervention."
  - Could this RFC 5880 text be quoted as-is, in the current I-D (with a reference?)

### NiTs
====

/It provides procedure where BFD state/It provides a procedure where BFD state/
/describes enabling and disabling/describe enabling and disabling/
/authentication state be allowed to change at most once/the authentication state be allowed to change at most once/

[Ballot comment]
Thanks for addressing my previous DISCUSS points (see https://mailarchive.ietf.org/arch/msg/rtg-bfd/WN2mVtMWb1e_L2cxyt8visES0vM/).

Nevertheless, I am balloting ABSTAIN because of the shepherd's write-up contains `No implementations and no known plans to implement` _AND_ I still think that this I-D is actually updating RFC  5880.

[Ballot comment]
Update:  Many thanks for the hard work to resolve my discuss.  I will be interested in seeing the results of the experiment!  [Note: I'm leaving my original comments below, just for the record.]

Thanks to Stephen Farrell for their secdir review.  His comments are relevant.

General:  Please change 'strong authentication' to 'authentication' throughout the specification.  One can hardly call MD5 and SHA1 keyed hashes 'strong'. [Note:  while SHA-1 keyed hashes might not be currently deprecated, they are definitely on NIST's list to deprecate.]

Intro:  There is a link to MD5, but not to SHA-1?  I suggest:  https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.180-4.pdf.

Intro:  Please add a little bit more explanation to remind the reader why these normally fast hashes are too slow/hard.  Please address both speed of the transmission and capability of the device performing the hashes.

Section 3, para 1:  Would one characterize 'Simple Password Authentication' as 'strong'?  or even 'adequate'?  Is there a reason it was left off the list of examples?  [Given there are only three options, it seems strange to use examples here.]

Section 3, para 4:  'as defined later in this document', which section is that?

Section 3, last para:  please ref which section in the specification this will be described.

Section 4, bullet list:  Why not list 'Simple Password Authentication', or 'NULL Auth'?  Are these not also less computationally intensive?  [assuming 'Simple Password Auth' was not listed because it isn't even 'adequate'.  And if NULL Authentication is ONLY suitable when the CPUs aren't capable of any processing, then that needs to be stated much more clearly in the stability draft.]

Section 4:  Please add a sentence about how other mechanisms might be added. [since this specification is not meant to be prescriptive with respect to the use of ISAAC.]

Section 5:  Do both sides (sender/receiver) calculate the timing of the Poll sequence? [to prevent the ability of the adversary to corrupt/block the Poll sequence messages]

Section 7:  Is the 'authentication present (A)' bit transmitted?  If so, where in Figure 1 is it?  Perhaps in the Opt. Mode?  If so, it would be easier to see if the same words were used in Para 1 as in the numbered list for Opt. Mode/Optimized Authentication Mode.

Section 7.2, para 2, Section 10.1, para 1:  If the goal is to allow other mechanisms, then the links to the ISAAC specification can be removed.  [Note:  there may be other places in the specification where this needs to be done.]

Section 7.2, para 3:  Do I understand this correctly?  If there is an issue switching from the original authentication mode to a 'computationally less intensive' mode, then the session is torn down?  That seems unfortunate.  If that isn't what this means, then perhaps revise.

Section 10:  Designating any of these mechanisms as 'strong' is disingenuous at best.  Please remove the word 'strong' from this specification.  Para 2 points out why this is true. 

Section 10:  Please add a sentence here which explains (justifies?) the level of authentication that is possible/practical for these systems.  Please address both speed of transmission and CPU capabilities.

Section 10:  Normally I would expect to see how the provision of symmetric keys (for keyed hashes, etc.) is accomplished. According to RFC 5880, keys are shipped across the network in the clear via the local/remote discriminator field.  This helps the attacker.  Please address this issue here, or point back to the relevant section in RFC 5880 where the mitigation is outlined.

[Ballot comment]
The shepherd report states that there are "no implementations and no known plans to implement."  Why publish this document if there no plans to run the experiment?

====

I support the DISCUS positions of Deb Cooley and Éric Vyncke.  In particular, Éric emphasizes the need to discuss how an experimental status RFC is making a normative change to PS status RFC (RFC5880).

** idnits reports:
  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

    (The document does seem to have the reference to RFC 2119 which the
    ID-Checklist requires).

[Ballot comment]
If there are no implementations and no plans to implement, why are we publishing this?

I support Deb's DISCUSS regarding the term "strong authentication" throughout. MD5 and SHA1 are *not* strong. In other contexts, they are the primitives that are used when stronger hash functions are too expensive and the additional security doesn't justify the cost.

I also support Gorry's DISCUSS on "optimized". I understand the reasoning, but that term doesn't make it clear what property is being improved without loss of function. In Section 10, it even asserts that this "enhances the ability to authenticate a BFD session" when in fact this explicitly *reduces* the authentication of the session. Perhaps this should be "lower effort" instead? Maybe even "lazy", if that's not seen as too judgmental?

The rationale for reducing overhead in sending packets that effectively say "nothing has changed" seems reasonable at first glance. However, it seems to me that an attacker who can drop the "significant change" packets could carry out an attack by fabricating "nothing has changed" messages and preventing detection of a change. "Nothing has changed" is still a message that needs to be protected. The requirement to "periodically test the session using the strong authentication mechanism" attempts to bound this risk. This should be discussed in the Security Considerations, emphasizing that the period used is the amount of time the parties are willing to allow an attacker to conceal a state change they attempted to communicate.

[Ballot comment]
I support the DISCUS positions of Deb Cooley and Éric Vyncke.  In particular, Éric emphasizes the need to discuss how an experimental status RFC is making a normative change to PS status RFC (RFC5880).

** idnits reports:
  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

    (The document does seem to have the reference to RFC 2119 which the
    ID-Checklist requires).

[Ballot discuss]
A discuss is merely the start of a conversation. 

This specification is misleading as it stands today:
1.  'strong authentication':  none of the mechanisms mentioned are 'strong'.  Please find another word/phrase to describe.
2.  operating situation:  Fast networks speeds combined with inadequate CPU capability will drive the solution which is practical.  Please explain this.
3.  key management:  According to RFC 5880, these are distributed in the clear as fields in the packets (local/remote discriminators), clearly available to an attacker.  This does not appear to be address in this draft or in RFC 5880.

My comments below mostly all point back to this discuss.

[Ballot comment]
Thanks to Stephen Farrell for their secdir review.  His comments are relevant.

General:  Please change 'strong authentication' to 'authentication' throughout the specification.  One can hardly call MD5 and SHA1 keyed hashes 'strong'. [Note:  while SHA-1 keyed hashes might not be currently deprecated, they are definitely on NIST's list to deprecate.]

Intro:  There is a link to MD5, but not to SHA-1?  I suggest:  https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.180-4.pdf.

Intro:  Please add a little bit more explanation to remind the reader why these normally fast hashes are too slow/hard.  Please address both speed of the transmission and capability of the device performing the hashes.

Section 3, para 1:  Would one characterize 'Simple Password Authentication' as 'strong'?  or even 'adequate'?  Is there a reason it was left off the list of examples?  [Given there are only three options, it seems strange to use examples here.]

Section 3, para 4:  'as defined later in this document', which section is that?

Section 3, last para:  please ref which section in the specification this will be described.

Section 4, bullet list:  Why not list 'Simple Password Authentication', or 'NULL Auth'?  Are these not also less computationally intensive?  [assuming 'Simple Password Auth' was not listed because it isn't even 'adequate'.  And if NULL Authentication is ONLY suitable when the CPUs aren't capable of any processing, then that needs to be stated much more clearly in the stability draft.]

Section 4:  Please add a sentence about how other mechanisms might be added. [since this specification is not meant to be prescriptive with respect to the use of ISAAC.]

Section 5:  Do both sides (sender/receiver) calculate the timing of the Poll sequence? [to prevent the ability of the adversary to corrupt/block the Poll sequence messages]

Section 7:  Is the 'authentication present (A)' bit transmitted?  If so, where in Figure 1 is it?  Perhaps in the Opt. Mode?  If so, it would be easier to see if the same words were used in Para 1 as in the numbered list for Opt. Mode/Optimized Authentication Mode.

Section 7.2, para 2, Section 10.1, para 1:  If the goal is to allow other mechanisms, then the links to the ISAAC specification can be removed.  [Note:  there may be other places in the specification where this needs to be done.]

Section 7.2, para 3:  Do I understand this correctly?  If there is an issue switching from the original authentication mode to a 'computationally less intensive' mode, then the session is torn down?  That seems unfortunate.  If that isn't what this means, then perhaps revise.

Section 10:  Designating any of these mechanisms as 'strong' is disingenuous at best.  Please remove the word 'strong' from this specification.  Para 2 points out why this is true. 

Section 10:  Please add a sentence here which explains (justifies?) the level of authentication that is possible/practical for these systems.  Please address both speed of transmission and CPU capabilities.

Section 10:  Normally I would expect to see how the provision of symmetric keys (for keyed hashes, etc.) is accomplished. According to RFC 5880, keys are shipped across the network in the clear via the local/remote discriminator field.  This helps the attacker.  Please address this issue here, or point back to the relevant section in RFC 5880 where the mitigation is outlined.

[Ballot comment]
# Gunter Van de Velde, RTG AD, comments for draft-ietf-bfd-optimizing-authentication-32

# The line numbers used are rendered from IETF idnits tool: https://author-tools.ietf.org/api/idnits?url=https://www.ietf.org/archive/id/draft-ietf-bfd-optimizing-authentication-32.txt

# for your convenience, please find some non-blocking COMMENTS

# I am missing an operational guidance section to help operators to operate optimized bfd.

# comments
# ========

17 Abstract
18
19   This document describes an experimental optimization to BFD
20   Authentication.  It provides a procedure where BFD state transitions
21   require strong authentication and permits the majority of BFD Control
22   Packets to use a less computationally intensive authentication
23   mechanism.  This enables BFD to scale better when there is a desire
24   to use strong authentication.

GV> This draft seems to suggest updating the procedures of RFC5880. Should that not be mentioned in some form or embodiment within the abstract? demand mode changes

143       | significant      | State change, a demand mode change (to  |
144       | change          | D bit) or a poll sequence change (P or  |
145       |                  | F bit).  Changes to BFD control packets |
146       |                  | that do not require a poll sequence,    |
147       |                  | such as bfd.DetectMult are also        |
148       |                  | considered as a significant change.    |

GV> The abstract mentions only state transitions, but with this definition of "significant change" there may be more included as just state change. Is my assumption correct?

What i considered as state change:
* Down → Init: When a system starts sending BFD packets to initiate a session.
* Init → Up: When a system receives valid BFD packets from the remote peer and both sides agree on session parameters.
* Up → Down: When a failure is detected (e.g., missing packets beyond the detection time threshold).
* Up → Init: May occur during reinitialization or configuration changes.

162   BFD.  For example, MD5 and SHA1 (Section 6.7 of [RFC5880]).

GV> If the list is short, maybe display them all and not an example set

164   The intention of these optimized procedures is to permit strong
165   authentication for BFD state changes and utilize the less
166   computationally intensive authentication mechanisms to provide
167   protection for the session in the Up state while performing less
168   overall work.  Such procedures will aid BFD session scaling without
169   compromising BFD session security.

GV>

"
The optimized procedures are intended to enable the use of strong authentication for BFD state transitions while relying on less computationally intensive mechanisms to protect sessions in the Up state. This approach reduces overall processing requirements and facilitates BFD session scaling without reducing session security.
"

171   All BFD Control Packets with the states AdminDown, Down, and Init
172   MUST use strong authentication.

GV> s/Packets with the states/Packets when in the state/

174   Once the BFD state machine has reached the Up state, it will continue
175   to send BFD Control Packets in the Up state for a period as discussed
176   in Section 7.2.  If optimized authentication mechanisms are in use,

GV> s/it will continue to send BFD Control Packets/it will continue to send computationally intensive BFD Control Packets/

180   The contents of an Up packet MUST NOT change aside from the
181   Authentication Section without strong authentication.

GV>

"
The contents of an Up packet, other than the Authentication Section, MUST NOT change unless strong authentication is in use.
"

233   This "strong reauthentication interval" for performing such periodic
234   tests using the strong authentication mechanism can be configured
235   depending on the capability of the system.

GV> The description here does not suggest min or maximum interval. It would be operational interesting to have a suggested interval guideline, and an absolute minimum of these polls to do per second or minute to avoid security degradation

237   Most packets transmitted on a BFD session are BFD Up packets.
238   Strongly authenticating a small subset of these packets with a Poll
239   sequence as described above, for example every one minute,
240   significantly reduces the computational demand for the system while
241   maintaining security of the session across the configured strong
242   reauthentication interval.

GV>

"
Most packets transmitted in a BFD session are Up packets. Strongly authenticating a limited subset of these packets, for example through a Poll sequence performed once per minute, substantially reduces system computational load while preserving session security across the configured strong reauthentication interval.
"

317   The values of the Optimized Authentication Mode field are:
318
319   1.  When using the strong authentication type for optimized BFD Auth
320       Types.
321
322   2.  When using the less computationally intensive authentication type
323       for optimized BFD Auth Types.

GV> are these numerical values  "1" and "2" set within the Opt. Mode field? or are both examples?
(easy fix to clarify)

329 7.1.  Transmitting and Receiving Using Optimized Authentication

GV> Would this be non-backward compatible, as rfc5880 assumes (i seem to remember) a single authentication type per session, and now with this experimental proposal we have multiple. Shoud the non-backward compatible property be called out in this section?

418 8.1.  Data Model Overview

GV> Some of the default values for this experimental draft are already defined in the YANG model. But for the purpose of making things easier to follow, wouldn’t it be helpful to also mention them explicitly in an operational guidance section? That way, readers working with optimized BFD don’t have to go digging through the model just to figure out what defaults they’re expected to use.

Kind Regards,
Gunter Van de Velde
RTG Area Director

[Ballot comment]
Hi Mahesh, Ashesh, Ankur, Manav, and Jeffrey,

Thanks for the effort put into this specification.

Thanks also to Jürgen Schönwälder for a review of an early version and to Jeff for the follow-up (especially the clarification about the struggle about the "performance" language).

Please find below some few comments:

# Confusing note

CURRENT:
  RFC XXXX, where XXXX is the number assigned to this document at the
  time of publication.

Please note that you are using RFC XXXX to refer to two distinct documents:

        "RFC XXXX: Optimizing BFD Authentication.";

and

    "RFC XXXX: Meticulous Keyed ISAAC for BFD Authentication.";

# Redundant behavior

Section 3
  The contents of an Up packet MUST NOT change aside from the
  Authentication Section without strong authentication.

Vs.

Section 6:
  In this specification, the contents of an Up packet MUST NOT change
  aside from the Authentication Section without strong authentication.

Keep the normative language in one place.

# Not only for configuration but also for state reporting

Section 8.1

OLD:
  The YANG 1.1 [RFC7950] model defined in this document augments the
  "ietf-bfd" module to configuration relevant to the management of
  the feature defined in this document. 

NEW:
  The YANG 1.1 [RFC7950] model defined in this document augments the
  "ietf-bfd" module to add data nodes relevant to the management of
  the feature defined in this document. 

# Add identities, not algos per se

Section 8.1

OLD:
  In particular, it adds crypto
  algorithms that are described in this model, and in Meticulous Keyed
  ISAAC for BFD Authentication [I-D.ietf-bfd-secure-sequence-numbers].

NEW:
In particular, it adds identities for crypto
  algorithms that are described in this model, and in Meticulous Keyed
  ISAAC for BFD Authentication [I-D.ietf-bfd-secure-sequence-numbers].

# Feature

Consider this change in Section 8.1

OLD:
  It adds a feature statement to enable optimized authentication.

NEW:
  It adds a feature to indicate optimized authentication.

# YANG terminology

CURRENT:
  This YANG module imports YANG Key Chain [RFC8177], A YANG Data Model
  for Routing Management (NMDA version) [RFC8349], and YANG Data Model
  for Bidirectional Forwarding Detection (BFD) [RFC9314].

This should reason about importing the various modules, not data models. Please refer to 8407bis which says:

“Likewise, "YANG module" should be used when using terms related to YANG module specifications (e.g., augmentation or deviation).“

# Consistency

Section 8.3 has:

CURRENT: prefix "bfdoa";

I suggest to be consistent with the pattern used so far for BFD (bfd-ip-mh, bfd-ip-sh, bfd-lag, etc.).

NEW: prefix bfd-oa;

# Feature Description

OLD:
      description
        "When enabled, this implementation supports optimized
          authentication as described in this document.";

NEW:
    description
      "Indicates that the implementation supports optimized
      authentication.";

Please note also that the module will live outside the document. You may add a reference statement.

# Redundant default statement

OLD:
        default "60";
        description
          "Interval of time after which strong authentication
            should be utilized to prevent an on-path-attacker attack.
            Default is 1 minute.

NEW:
        default "60";
        description
          "Interval of time after which strong authentication
            should be utilized to prevent an on-path-attacker attack.

# Not maintained by IANA

OLD:
  name:        ietf-bfd-opt-auth
  namespace:    urn:ietf:params:xml:ns:yang:ietf-bfd-opt-auth
  prefix:      bfdoa
  reference:    RFC XXXX

NEW:
  name:        ietf-bfd-opt-auth
  namespace:    urn:ietf:params:xml:ns:yang:ietf-bfd-opt-auth
  prefix:      bfd-oa
  maintained by IANA? N
  reference:    RFC XXXX

# Security template

Please update 10.2 to follow the template in RFC8407bis.

Cheers,
Med

[Ballot discuss]
Thank you for the work put into this document. I have one topic that I'd like to discuss:

### 1. In the title and throughout the document, I a became little unsure about the words
  optimized BFD authentication - The title worries me. I
  think the words "optimised" could suggest stronger authentication, which seems
  to me to not be the case, and hence this could be potentially confusing because
  this is not really optimised for better authentication, but a more
  lightweight implementation of authentication, which I understand from the I-D
  is expected could also make authentication more easy to deploy, which could have merit.

As noted in https://datatracker.ietf.org/doc/statement-iesg-handling-ballot-positions-20220121/, a DISCUSS ballot is a request to have a discussion to consider the topic above.

[Ballot comment]
Thanks for preparing this I-D, I have the following comments which I hope will help revise this I-D.

### 1. Thank you to Marcus Ihlar for his TSV-ART review, see: https://datatracker.ietf.org/doc/review-ietf-bfd-optimizing-authentication-28-tsvart-lc-ihlar-2025-08-18/

As noted in the reviwe, could the editors please add a short discussion on loss and reauthentication
in Section 5, or in an Operational Considerations section?

### 2. The I-D text ought to say why the document is experimental, please could you add to
  the Introduction by citing the Appendix that explains this.

### 3. The I-D currently states: "All BFD Control Packets with the states AdminDown, Down, and Init
  require strong authentication." - could this be a RFC-2119 requirement?
  Please consider making this a nomative case for this I-D , i.e. make this "REQUIRES",
  or the REQUIRES in the following:
  "In addition to these requirements, BFD "significant changes" require
  strong authentication."

### 5. The I-D currently states:
  "When using the less computationally intensive authentication
  mechanism, BFD should periodically test the session using the strong
  authentication mechanism."
  - I'd agree, but I do think the text needs to explain why this is
  desirable, i.e. to justify why people SHOULD think seriously about
  enabling this test.

### 6. The I-D currently states:
  "Once
  enabled, every packet must have Authentication Bit set and the
  associated Authentication Type appended."
  - Please cit the section here, I could not be sure what was cited?

### 7. The I-D currently states:
  "As a security precaution, it mentions that
  authentication state be allowed to change at most once"
  Whereas, RFC 5880 use RFC-2119 text:
  "In order to avoid security risks, implementations using this method
  SHOULD only allow the authentication state to be changed at most once
  without some form of intervention."
  - Could this RFC 5880 text be quoted as-is, in the current I-D (with a reference?)

### NiTs
====

/It provides procedure where BFD state/It provides a procedure where BFD state/
/describes enabling and disabling/describe enabling and disabling/
/authentication state be allowed to change at most once/the authentication state be allowed to change at most once/

[Ballot comment]
1. Thank you to Marcus Ihlar for his TSV-ART review, see: https://datatracker.ietf.org/doc/review-ietf-bfd-optimizing-authentication-28-tsvart-lc-ihlar-2025-08-18/

As noted, please add a short discussion on loss and reauthentication in Section 5, or in an Operational
Considerations section, might be warranted.

2. The I-D does not set-out why the document is experimental.
  I don't argue that this is the correct status, but a few
  sentences explaining this would be useful in the document when published.

3. The I-D currently states: "All BFD Control Packets with the states AdminDown, Down, and Init
  require strong authentication." - why is this not a RFC-2119 requirement?
  If it could be, please consider making this a nomative case for this I-D , ie.e. make this "REQUIRES".

4. As in (3) above - why does this I-D not make the following a RFC-2119 requirement?
  "In addition to these requirements, BFD "significant changes" require
  strong authentication."

5. The I-D currently states:
  "When using the less computationally intensive authentication
  mechanism, BFD should periodically test the session using the strong
  authentication mechanism."
  - I'd agree, but I do think the text needs to explain why this is
  desirable, i.e. to justify why people SHOULD think seriously about
  enabling this test.

6. The I-D currently states:
  "Once
  enabled, every packet must have Authentication Bit set and the
  associated Authentication Type appended."
  - can we cite the sectoion here, I could not be sure what was cited?

7. The I-D currently states:
"As a security precaution, it mentions that
  authentication state be allowed to change at most once"
  RFC 5880 states:
  "In order to avoid security risks, implementations using this method
  SHOULD only allow the authentication state to be changed at most once
  without some form of intervention."
  - could this text be quoted as-is, in the I-D (with a reference?)


NiTs
====

/It provides procedure where BFD state/It provides a procedure where BFD state/
/describes enabling and disabling/describe enabling and disabling/
/authentication state be allowed to change at most once/the authentication state be allowed to change at most once/

[Ballot comment]
1. Thank you to Marcus Ihlar for his TSV-ART review, see: https://datatracker.ietf.org/doc/review-ietf-bfd-optimizing-authentication-28-tsvart-lc-ihlar-2025-08-18/

As noted, please add a short discussion on loss and reauthentication in Section 5, or in an Operational
Considerations section, might be warranted.

2. The I-D does not set-out why the document is experimental.
  I don't argue that this is the correct status, but a few
  sentences explaining this would be useful in the document when published.

3. The I-D currently states: "All BFD Control Packets with the states AdminDown, Down, and Init
  require strong authentication." - why is this not a RFC-2119 requirement?
  If it could be, please consider making this a nomative case for this I-D , ie.e. make this "REQUIRES".

4. As in (3) above - why does this I-D not make the following a RFC-2119 requirement?
  "In addition to these requirements, BFD "significant changes" require
  strong authentication."

5. The I-D currently states:
  "When using the less computationally intensive authentication
  mechanism, BFD should periodically test the session using the strong
  authentication mechanism."
  - I'd agree, but I do think the text needs to explain why this is
  desirable, i.e. to justify why people SHOULD think seriously about
  enabling this test.

6. The I-D currently states:
  "Once
  enabled, every packet must have Authentication Bit set and the
  associated Authentication Type appended."
  - can we cite the sectoion here, I could not be sure what was cited?

  RFC 5880 states:
  "In order to avoid security risks, implementations using this method
  SHOULD only allow the authentication state to be changed at most once
  without some form of intervention."
  - could this text be quoted as-is, in the I-D (with a reference?)


NiTs
====

/It provides procedure where BFD state/It provides a procedure where BFD state/
/describes enabling and disabling/describe enabling and disabling/
/authentication state be allowed to change at most once/the authentication state be allowed to change at most once/

[Ballot comment]
1. Thank you to Marcus Ihlar for his TSV-ART review, see: https://datatracker.ietf.org/doc/review-ietf-bfd-optimizing-authentication-28-tsvart-lc-ihlar-2025-08-18/

As noted, please add a short discussion on loss and reauthentication in Section 5, or in an Operational
Considerations section, might be warranted.

2. The I-D does not set-out why the document is experimental. I don't argue that this is the correct status, but a few sentences explaining this would be useful in the document when published.

3. The I-D currently states: "All BFD Control Packets with the states AdminDown, Down, and Init
  require strong authentication." - why is this not a RFC-2119 requirement?
If it could be, please consider updating the I-D to make this "REQUIRES"
NiTs
====

/It provides procedure where BFD state/It provides a procedure where BFD state/

[Ballot discuss]

# Éric Vyncke, INT AD, comments for draft-ietf-bfd-optimizing-authentication-29
CC @evyncke

Thank you for the work put into this document.

Please find below blocking DISCUSS points, some non-blocking COMMENT points/nits (replies would be appreciated even if only for my own education).

Special thanks to Reshad Rahman for the shepherd's detailed write-up including the WG consensus *and* the justification of the intended status.

I hope that this review helps to improve the document,

Regards,

-éric


## DISCUSS (blocking)

As noted in https://datatracker.ietf.org/doc/statement-iesg-handling-ballot-positions-20220121/, a DISCUSS ballot is a request to have a discussion on the points below; I really think that the document would be improved with a change here, but can be convinced otherwise.

### Sections 6 & 7

Should this document formally update RFC 5880 ? Especially based on section 7 `This document repurposes the "Reserved" field as the "Optimized Authentication Mode" field when used for authentication types for optimized BFD procedures.`

### Section 7

s/excepting that Auth Type is *still* TBD and that *Reserved* is set to 1/excepting that Auth Type is TBD and that *"Optimized Authentication Mode"* is set to 1/

As 'Reserved' has just been reused, then the new field name must be used.

### Section 7.1

The text is about OptMode being 1 or 2 while the previous section introduced these values with "For example" and restricting it to MD-5-related authentication. It is either an example (like section 7) or normative (like section 7.1).

### Section 9

Even more critical, there is no request to the IANA to allocate the `TBD` authentication type in https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml#bfd-parameters-2

[Ballot comment]

## COMMENTS (non-blocking)

### Section 3

In `If optimized authentication mechanisms are in use` the 'optimized authentication mechanisms' have not been formally specified as 'the mechanisms described in this document'. Suggest adding it either here '(i.e., this specication)' or in the terminology section.

Unsure whether this draft is the right place to say "SHA-2 is left for future study" (if BFD does not support it).

### Section 3.1

s/do not require a poll sequence, such as a bfd.DetectMult are/do not require a poll sequence, such as a bfd.DetectMult*,* are/ ?

### Section 4

Readers (including me) will welcome an expansion of ISAAC.

### Section 5

Is it about "reauthentication" or "authentication refresh" ?

### Section 8

s/Optimizing Authentication YANG Model/Optimizing Authentication YANG Data Model/ ?

[Ballot comment]
This document is one of a 3 document set from the BFD WG that enhances BFD authentication mechanism. The suggested order for reviewing them is as follows:

1) draft-ietf-bfd-optimizing-authentication (specifies extension to BFD auth with an optimized auth mechanism)
2) draft-ietf-bfd-secure-sequence-numbers (specifies an optimized auth mechanism based on meticulously keyed ISAAC that uses (1))
3) draft-ietf-bfd-stability (is not an auth mechanism but uses the auth sequence numbers for monitoring loss of BFD packets)

Nit from the expert: Oops, as with the other doc in this series, the examples e.g. A.1 in this case, contain multiple XML documents squashed together, which I think hurts readability. --

That makes sense, we’re just having a minor terminology conflict here.  These are in XML and XML defines a “document” as the stuff between a start  and end tag tag like  … . So from the XML PoV that example is 3 documents. And most XML software will only read one “document” at a time.  If people typically use software that accepts/requires multiple XML documents squashed together like that, then OK, but I think it should be at least mentioned?

Even putting a blank line between the XML documents in the example would reduce the friction.

IESG/Authors/WG Chairs:

IANA has completed its review of draft-ietf-bfd-optimizing-authentication-28. If any part of this review is inaccurate, please let us know.

IANA understands that, upon approval of this document, there are two actions which we must complete.

First, in the ns registry in the IETF XML Registry located at:

https://www.iana.org/assignments/xml-registry/

a single new namespace will be registered as follows:

ID: yang:ietf-bfd-opt-auth
URI: urn:ietf:params:xml:ns:yang:ietf-bfd-opt-auth
Filename: [ TBD-at-Registration ]
Reference: [ RFC-to-be ]

As this document requests a registration in an Expert Review or Specification Required (see RFC 8126) registry, we have initiated the required Expert Review via a separate request. Expert review will need to be completed before your document can be approved for publication as an RFC.

Second, in the YANG Module Names registry in the YANG Parameters registry group located at:

https://www.iana.org/assignments/yang-parameters/

a single, new YANG module will be registered as follows:

Name: ietf-bfd-opt-auth
File: [ TBD-at-Registration ]
Maintained by IANA? N
Namespace: urn:ietf:params:xml:ns:yang:ietf-bfd-opt-auth
Prefix: bfdoa
Module:
Reference: [ RFC-to-be ]

While the YANG module name will be registered after the IESG approves the document, the YANG module file will be posted after the RFC Editor notifies us that the document has been published.

We understand that these are the only actions required to be completed upon approval of this document.

NOTE: The actions requested in this document will not be completed until the document has been approved for publication as an RFC. This message is meant only to confirm the list of actions that will be performed.

For definitions of IANA review states, please see:

https://datatracker.ietf.org/help/state/draft/iana-review

Thank you,

David Dong
IANA Services Sr. Specialist

The following Last Call announcement was sent out (ends 2025-08-18):

From: The IESG
To: IETF-Announce
CC: Reshad Rahman , bfd-chairs@ietf.org, draft-ietf-bfd-optimizing-authentication@ietf.org, ketant.ietf@gmail.com, rrahman@cisco.com, rtg-bfd@ietf.org
Reply-To: last-call@ietf.org
Sender:
Subject: Last Call:  (Optimizing BFD Authentication) to Experimental RFC


The IESG has received a request from the Bidirectional Forwarding Detection
WG (bfd) to consider the following document: - 'Optimizing BFD Authentication'
  as Experimental RFC

The IESG plans to make a decision in the next few weeks, and solicits final
comments on this action. Please send substantive comments to the
last-call@ietf.org mailing lists by 2025-08-18. Exceptionally, comments may
be sent to iesg@ietf.org instead. In either case, please retain the beginning
of the Subject line to allow automated sorting.

Abstract


  This document describes an experimental optimization to BFD
  Authentication.  It provides procedure where BFD state transitions
  require strong authentication and permits the majority of BFD Control
  Packets to use a less computationally intensive authentication
  mechanism.  This enables BFD to scale better when there is a desire
  to use strong authentication.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-bfd-optimizing-authentication/


The following IPR Declarations may be related to this I-D:

  https://datatracker.ietf.org/ipr/3328/

Review of draft-ietf-bfd-optimizing-authentication-26
=======================================================================================

Authors have addressed AD-review comments @ https://mailarchive.ietf.org/arch/msg/rtg-bfd/xbqjw2vFztDesC6DKyIsRczcgIs/

Shepherding co-chair then asked for comments on the updates, see https://mailarchive.ietf.org/arch/msg/rtg-bfd/dvdro7nBOEu8WKr2Y0VKOz7jZCA/

Comments provided @ https://mailarchive.ietf.org/arch/msg/rtg-bfd/aeaBX7ZFDlupcxpjydgRttHaCtE/ have been addressed.

Comment on -26: there is 1 instance of "important BFD state transitions" left in the Introduction section. All other instances of "important state transitions" are gone and that remaining instance should be removed too.

Review of draft-ietf-bfd-optimizing-authentication-24
=======================================================================================

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

Strong consensus of a few individuals.
The initial revision of this document is from 2015. Since then there have been multiple
discussions on the BFD alias and in in-person WG meetings. The "recent" changes to the
document to use ISAAC are the ones on which the WG has been mostly silent.

There has been opposition by one person (see 2 below).

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

There has been controversy because of the IPR Disclosure. Concern is FRAND licensing terms.
https://mailarchive.ietf.org/arch/msg/rtg-bfd/05jWvSvZioDvOlZfNAZKGMOw5ng/
https://mailarchive.ietf.org/arch/msg/rtg-bfd/u8rvWwvDWRKI3jseGHecAB9WtDo/

However the authors have expressed that since the patent has been filed, the document has diverged from what was filed:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/LFI1DvUHBUFBjz5Yxgvs4u6_2XU/
https://mailarchive.ietf.org/arch/msg/rtg-bfd/KpT0VQoLiExRzvzYe1DwL9JkJ4U/

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize the areas of conflict in separate email messages to the
  responsible Area Director. (It should be in a separate email because this
  questionnaire is publicly available.)

No

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

No implementations and no known plans to implement.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

No and no.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

The document has undergone a YANG Doctor review.

The authors have addressed all the comments.


7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation?

Yes.

  If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time?

No errors and no warnings.

  Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

Yes.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

YANG has been validated.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

The document is clearly written and nearly ready.

The authors have addressed all review comments.
https://mailarchive.ietf.org/arch/msg/rtg-bfd/ca_gCMOCyXGNhhTBAvg5lGLXJK8/

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

There has been a secdir review and comments have been addressed:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/303D-DZ2DVFr9frgy75b6yyiILk/

No comments from RtgDir review:
https://mailarchive.ietf.org/arch/msg/rtg-dir/El6oDoBT6r40I9IWC-YdJNEiPPM/

Comments from opsdir review have been addressed:
https://mailarchive.ietf.org/arch/msg/ops-dir/xJiWAeDtJFSdwUSpOnztZjgXwZw/

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])?

Experimental as indicated on title page.

    Why is this the proper type
    of RFC?

  This document describes an experimental update to BFD [RFC5880].
  This experiment is intended to provide additional insights into what
  happens when the optimized authentication method defined in this
  document is used.  Here are the reasons why this document is on the
  Experimental track:

  *  In the initial stages of the document, there were significant
      participation and reviews from the working group.  Since then,
      there has been considerable changes to the document, e.g. the use
      of ISAAC, allowing for ISAAC bootstrapping when a BFD session
      comes up and use of a single Auth Type to indicate use of
      optimized authentication etc.  These changes did not get
      significant review from the working group and therefore does not
      meet the bar set in Section 4.1.1 of [RFC2026]

  *  There are no known implementations (even proof-of-concept) or
      implementation plans.  As a result, we do not currently know if
      there will be interop issues with legacy implementations or what
      exactly are the performance benefits of the optimization method.

  *  The work in this document could become very valuable in the
      future, especially if the need for deploying BFD authentication at
      scale becomes a reality.

    Do all Datatracker state attributes correctly reflect this intent?
Yes.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]?
Yes.

    To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.
Yes: https://mailarchive.ietf.org/arch/msg/rtg-bfd/tB3E6nl6N4w7wGIPMXsDF2gDdiE/

13. Has each author, editor, and contributor shown their willingness to be
    listed as such?
Yes.

    If the total number of authors and editors on the front page
    is greater than five, please provide a justification.
N/A.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)
  Miscellaneous warnings:
  ----------------------------------------------------------------------------

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

    (The document does seem to have the reference to RFC 2119 which the
    ID-Checklist requires).
  -- The document date (16 April 2025) is 18 days in the past.  Is this
    intentional?

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].
No.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?
N/A

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.
No.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?
No. Note that this document should be in the same bundle as draft-ietf-bfd-secure-sequence-numbers and draft-ietf-bfd-stability (which are updated in "locked-step" with this document).

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.
No. This is an experimental document.

20. Describe the document shepherd's review of the IANA considerations section,
    especially with regard to its consistency with the body of the document.
    Confirm that all aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).
Section 6 matches the rest of the document and confirming the above where applicable.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.
Assignment from the “BFD Authentication Types” registry requires Expert review. Checked https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml
There is also an updated IANA YANG module in the appendix.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://wiki.ietf.org/group/ops/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://wiki.ietf.org/group/iesg/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

Review of draft-ietf-bfd-optimizing-authentication-26
=======================================================================================

Authors have addressed AD-review comments @ https://mailarchive.ietf.org/arch/msg/rtg-bfd/xbqjw2vFztDesC6DKyIsRczcgIs/

Shepherding co-chair then asked for comments on the updates, see https://mailarchive.ietf.org/arch/msg/rtg-bfd/dvdro7nBOEu8WKr2Y0VKOz7jZCA/

There is 1 instance of "important BFD state transitions" left in the Introduction section. All other instances of "important state transitions" are gone and that remaining instance should be removed too.

Review of draft-ietf-bfd-optimizing-authentication-24
=======================================================================================

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

Strong consensus of a few individuals.
The initial revision of this document is from 2015. Since then there have been multiple
discussions on the BFD alias and in in-person WG meetings. The "recent" changes to the
document to use ISAAC are the ones on which the WG has been mostly silent.

There has been opposition by one person (see 2 below).

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

There has been controversy because of the IPR Disclosure. Concern is FRAND licensing terms.
https://mailarchive.ietf.org/arch/msg/rtg-bfd/05jWvSvZioDvOlZfNAZKGMOw5ng/
https://mailarchive.ietf.org/arch/msg/rtg-bfd/u8rvWwvDWRKI3jseGHecAB9WtDo/

However the authors have expressed that since the patent has been filed, the document has diverged from what was filed:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/LFI1DvUHBUFBjz5Yxgvs4u6_2XU/
https://mailarchive.ietf.org/arch/msg/rtg-bfd/KpT0VQoLiExRzvzYe1DwL9JkJ4U/

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize the areas of conflict in separate email messages to the
  responsible Area Director. (It should be in a separate email because this
  questionnaire is publicly available.)

No

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

No implementations and no known plans to implement.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

No and no.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

The document has undergone a YANG Doctor review.

The authors have addressed all the comments.


7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation?

Yes.

  If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time?

No errors and no warnings.

  Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

Yes.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

YANG has been validated.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

The document is clearly written and nearly ready.

The authors have addressed all review comments.
https://mailarchive.ietf.org/arch/msg/rtg-bfd/ca_gCMOCyXGNhhTBAvg5lGLXJK8/

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

There has been a secdir review and comments have been addressed:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/303D-DZ2DVFr9frgy75b6yyiILk/

No comments from RtgDir review:
https://mailarchive.ietf.org/arch/msg/rtg-dir/El6oDoBT6r40I9IWC-YdJNEiPPM/

Comments from opsdir review have been addressed:
https://mailarchive.ietf.org/arch/msg/ops-dir/xJiWAeDtJFSdwUSpOnztZjgXwZw/

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])?

Experimental as indicated on title page.

    Why is this the proper type
    of RFC?

  This document describes an experimental update to BFD [RFC5880].
  This experiment is intended to provide additional insights into what
  happens when the optimized authentication method defined in this
  document is used.  Here are the reasons why this document is on the
  Experimental track:

  *  In the initial stages of the document, there were significant
      participation and reviews from the working group.  Since then,
      there has been considerable changes to the document, e.g. the use
      of ISAAC, allowing for ISAAC bootstrapping when a BFD session
      comes up and use of a single Auth Type to indicate use of
      optimized authentication etc.  These changes did not get
      significant review from the working group and therefore does not
      meet the bar set in Section 4.1.1 of [RFC2026]

  *  There are no known implementations (even proof-of-concept) or
      implementation plans.  As a result, we do not currently know if
      there will be interop issues with legacy implementations or what
      exactly are the performance benefits of the optimization method.

  *  The work in this document could become very valuable in the
      future, especially if the need for deploying BFD authentication at
      scale becomes a reality.

    Do all Datatracker state attributes correctly reflect this intent?
Yes.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]?
Yes.

    To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.
Yes: https://mailarchive.ietf.org/arch/msg/rtg-bfd/tB3E6nl6N4w7wGIPMXsDF2gDdiE/

13. Has each author, editor, and contributor shown their willingness to be
    listed as such?
Yes.

    If the total number of authors and editors on the front page
    is greater than five, please provide a justification.
N/A.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)
  Miscellaneous warnings:
  ----------------------------------------------------------------------------

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

    (The document does seem to have the reference to RFC 2119 which the
    ID-Checklist requires).
  -- The document date (16 April 2025) is 18 days in the past.  Is this
    intentional?

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].
No.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?
N/A

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.
No.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?
No. Note that this document should be in the same bundle as draft-ietf-bfd-secure-sequence-numbers and draft-ietf-bfd-stability (which are updated in "locked-step" with this document).

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.
No. This is an experimental document.

20. Describe the document shepherd's review of the IANA considerations section,
    especially with regard to its consistency with the body of the document.
    Confirm that all aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).
Section 6 matches the rest of the document and confirming the above where applicable.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.
Assignment from the “BFD Authentication Types” registry requires Expert review. Checked https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml
There is also an updated IANA YANG module in the appendix.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://wiki.ietf.org/group/ops/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://wiki.ietf.org/group/iesg/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

Review of draft-ietf-bfd-optimizing-authentication-26
=======================================================================================

Authors have addressed AD-review comments @ https://mailarchive.ietf.org/arch/msg/rtg-bfd/xbqjw2vFztDesC6DKyIsRczcgIs/

Shepherding co-chair then asked for comments for updates, see https://mailarchive.ietf.org/arch/msg/rtg-bfd/dvdro7nBOEu8WKr2Y0VKOz7jZCA/

There is 1 instance of "important BFD state transitions" left in the Introduction section. All other instances of "important state transitions" are gone and that remaining instance should be removed too.

Review of draft-ietf-bfd-optimizing-authentication-24
=======================================================================================

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

Strong consensus of a few individuals.
The initial revision of this document is from 2015. Since then there have been multiple
discussions on the BFD alias and in in-person WG meetings. The "recent" changes to the
document to use ISAAC are the ones on which the WG has been mostly silent.

There has been opposition by one person (see 2 below).

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

There has been controversy because of the IPR Disclosure. Concern is FRAND licensing terms.
https://mailarchive.ietf.org/arch/msg/rtg-bfd/05jWvSvZioDvOlZfNAZKGMOw5ng/
https://mailarchive.ietf.org/arch/msg/rtg-bfd/u8rvWwvDWRKI3jseGHecAB9WtDo/

However the authors have expressed that since the patent has been filed, the document has diverged from what was filed:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/LFI1DvUHBUFBjz5Yxgvs4u6_2XU/
https://mailarchive.ietf.org/arch/msg/rtg-bfd/KpT0VQoLiExRzvzYe1DwL9JkJ4U/

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize the areas of conflict in separate email messages to the
  responsible Area Director. (It should be in a separate email because this
  questionnaire is publicly available.)

No

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

No implementations and no known plans to implement.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

No and no.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

The document has undergone a YANG Doctor review.

The authors have addressed all the comments.


7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation?

Yes.

  If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time?

No errors and no warnings.

  Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

Yes.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

YANG has been validated.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

The document is clearly written and nearly ready.

The authors have addressed all review comments.
https://mailarchive.ietf.org/arch/msg/rtg-bfd/ca_gCMOCyXGNhhTBAvg5lGLXJK8/

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

There has been a secdir review and comments have been addressed:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/303D-DZ2DVFr9frgy75b6yyiILk/

No comments from RtgDir review:
https://mailarchive.ietf.org/arch/msg/rtg-dir/El6oDoBT6r40I9IWC-YdJNEiPPM/

Comments from opsdir review have been addressed:
https://mailarchive.ietf.org/arch/msg/ops-dir/xJiWAeDtJFSdwUSpOnztZjgXwZw/

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])?

Experimental as indicated on title page.

    Why is this the proper type
    of RFC?

  This document describes an experimental update to BFD [RFC5880].
  This experiment is intended to provide additional insights into what
  happens when the optimized authentication method defined in this
  document is used.  Here are the reasons why this document is on the
  Experimental track:

  *  In the initial stages of the document, there were significant
      participation and reviews from the working group.  Since then,
      there has been considerable changes to the document, e.g. the use
      of ISAAC, allowing for ISAAC bootstrapping when a BFD session
      comes up and use of a single Auth Type to indicate use of
      optimized authentication etc.  These changes did not get
      significant review from the working group and therefore does not
      meet the bar set in Section 4.1.1 of [RFC2026]

  *  There are no known implementations (even proof-of-concept) or
      implementation plans.  As a result, we do not currently know if
      there will be interop issues with legacy implementations or what
      exactly are the performance benefits of the optimization method.

  *  The work in this document could become very valuable in the
      future, especially if the need for deploying BFD authentication at
      scale becomes a reality.

    Do all Datatracker state attributes correctly reflect this intent?
Yes.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]?
Yes.

    To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.
Yes: https://mailarchive.ietf.org/arch/msg/rtg-bfd/tB3E6nl6N4w7wGIPMXsDF2gDdiE/

13. Has each author, editor, and contributor shown their willingness to be
    listed as such?
Yes.

    If the total number of authors and editors on the front page
    is greater than five, please provide a justification.
N/A.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)
  Miscellaneous warnings:
  ----------------------------------------------------------------------------

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

    (The document does seem to have the reference to RFC 2119 which the
    ID-Checklist requires).
  -- The document date (16 April 2025) is 18 days in the past.  Is this
    intentional?

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].
No.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?
N/A

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.
No.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?
No. Note that this document should be in the same bundle as draft-ietf-bfd-secure-sequence-numbers and draft-ietf-bfd-stability (which are updated in "locked-step" with this document).

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.
No. This is an experimental document.

20. Describe the document shepherd's review of the IANA considerations section,
    especially with regard to its consistency with the body of the document.
    Confirm that all aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).
Section 6 matches the rest of the document and confirming the above where applicable.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.
Assignment from the “BFD Authentication Types” registry requires Expert review. Checked https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml
There is also an updated IANA YANG module in the appendix.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://wiki.ietf.org/group/ops/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://wiki.ietf.org/group/iesg/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

Review of draft-ietf-bfd-optimizing-authentication-24
=======================================================================================

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

Strong consensus of a few individuals.
The initial revision of this document is from 2015. Since then there have been multiple
discussions on the BFD alias and in in-person WG meetings. The "recent" changes to the
document to use ISAAC are the ones on which the WG has been mostly silent.

There has been opposition by one person (see 2 below).

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

There has been controversy because of the IPR Disclosure. Concern is FRAND licensing terms.
https://mailarchive.ietf.org/arch/msg/rtg-bfd/05jWvSvZioDvOlZfNAZKGMOw5ng/
https://mailarchive.ietf.org/arch/msg/rtg-bfd/u8rvWwvDWRKI3jseGHecAB9WtDo/

However the authors have expressed that since the patent has been filed, the document has diverged from what was filed:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/LFI1DvUHBUFBjz5Yxgvs4u6_2XU/
https://mailarchive.ietf.org/arch/msg/rtg-bfd/KpT0VQoLiExRzvzYe1DwL9JkJ4U/

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize the areas of conflict in separate email messages to the
  responsible Area Director. (It should be in a separate email because this
  questionnaire is publicly available.)

No

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

No implementations and no known plans to implement.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

No and no.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

The document has undergone a YANG Doctor review.

The authors have addressed all the comments.


7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation?

Yes.

  If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time?

No errors and no warnings.

  Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

Yes.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

YANG has been validated.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

The document is clearly written and nearly ready.

The authors have addressed all review comments.
https://mailarchive.ietf.org/arch/msg/rtg-bfd/ca_gCMOCyXGNhhTBAvg5lGLXJK8/

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

There has been a secdir review and comments have been addressed:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/303D-DZ2DVFr9frgy75b6yyiILk/

No comments from RtgDir review:
https://mailarchive.ietf.org/arch/msg/rtg-dir/El6oDoBT6r40I9IWC-YdJNEiPPM/

Comments from opsdir review have been addressed:
https://mailarchive.ietf.org/arch/msg/ops-dir/xJiWAeDtJFSdwUSpOnztZjgXwZw/

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])?

Experimental as indicated on title page.

    Why is this the proper type
    of RFC?

  This document describes an experimental update to BFD [RFC5880].
  This experiment is intended to provide additional insights into what
  happens when the optimized authentication method defined in this
  document is used.  Here are the reasons why this document is on the
  Experimental track:

  *  In the initial stages of the document, there were significant
      participation and reviews from the working group.  Since then,
      there has been considerable changes to the document, e.g. the use
      of ISAAC, allowing for ISAAC bootstrapping when a BFD session
      comes up and use of a single Auth Type to indicate use of
      optimized authentication etc.  These changes did not get
      significant review from the working group and therefore does not
      meet the bar set in Section 4.1.1 of [RFC2026]

  *  There are no known implementations (even proof-of-concept) or
      implementation plans.  As a result, we do not currently know if
      there will be interop issues with legacy implementations or what
      exactly are the performance benefits of the optimization method.

  *  The work in this document could become very valuable in the
      future, especially if the need for deploying BFD authentication at
      scale becomes a reality.

    Do all Datatracker state attributes correctly reflect this intent?
Yes.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]?
Yes.

    To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.
Yes: https://mailarchive.ietf.org/arch/msg/rtg-bfd/tB3E6nl6N4w7wGIPMXsDF2gDdiE/

13. Has each author, editor, and contributor shown their willingness to be
    listed as such?
Yes.

    If the total number of authors and editors on the front page
    is greater than five, please provide a justification.
N/A.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)
  Miscellaneous warnings:
  ----------------------------------------------------------------------------

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

    (The document does seem to have the reference to RFC 2119 which the
    ID-Checklist requires).
  -- The document date (16 April 2025) is 18 days in the past.  Is this
    intentional?

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].
No.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?
N/A

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.
No.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?
No. Note that this document should be in the same bundle as draft-ietf-bfd-secure-sequence-numbers and draft-ietf-bfd-stability (which are updated in "locked-step" with this document).

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.
No. This is an experimental document.

20. Describe the document shepherd's review of the IANA considerations section,
    especially with regard to its consistency with the body of the document.
    Confirm that all aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).
Section 6 matches the rest of the document and confirming the above where applicable.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.
Assignment from the “BFD Authentication Types” registry requires Expert review. Checked https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml
There is also an updated IANA YANG module in the appendix.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://wiki.ietf.org/group/ops/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://wiki.ietf.org/group/iesg/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

This document needs to be processed along with draft-ietf-bfd-secure-sequence-numbers and draft-ietf-bfd-stability due to interdependencies between them.

Awaiting the response to AD review and posting of updates from the authors of the other two documents before a final check/pass can be made.

=======================================================================================
Update May 4th 2025 on draft-ietf-bfd-optimizing-authentication-24
Update for 2) on May 22nd 2025 and May 23rd 2025

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

Strong consensus of a few individuals.
The initial revision of this document is from 2015. Since then there have been multiple
discussions on the BFD alias and in in-person WG meetings. The "recent" changes to the
document to use ISAAC are the ones on which the WG has been mostly silent.

There has been opposition by one person (see 2 below).

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

There has been controversy because of the IPR Disclosure. Concern is FRAND licensing terms.
https://mailarchive.ietf.org/arch/msg/rtg-bfd/u8rvWwvDWRKI3jseGHecAB9WtDo/

However the authors have expressed that since the patent has been filed, the document has diverged from what was filed:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/LFI1DvUHBUFBjz5Yxgvs4u6_2XU/
https://mailarchive.ietf.org/arch/msg/rtg-bfd/KpT0VQoLiExRzvzYe1DwL9JkJ4U/

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize the areas of conflict in separate email messages to the
  responsible Area Director. (It should be in a separate email because this
  questionnaire is publicly available.)

No

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

No implementations and no known plans to implement.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

No and no.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

The document has undergone a YANG Doctor review.

The authors have addressed all the comments.


7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation?

Yes.

  If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time?

No errors and no warnings.

  Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

Yes.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

YANG has been validated.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

The document is clearly written and nearly ready.

The authors have addressed all review comments.
https://mailarchive.ietf.org/arch/msg/rtg-bfd/ca_gCMOCyXGNhhTBAvg5lGLXJK8/

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

There has been a secdir review and comments have been addressed:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/303D-DZ2DVFr9frgy75b6yyiILk/

No comments from RtgDir review:
https://mailarchive.ietf.org/arch/msg/rtg-dir/El6oDoBT6r40I9IWC-YdJNEiPPM/

Comments from opsdir review have been addressed:
https://mailarchive.ietf.org/arch/msg/ops-dir/xJiWAeDtJFSdwUSpOnztZjgXwZw/

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])?

Experimental as indicated on title page.

    Why is this the proper type
    of RFC?

  This document describes an experimental update to BFD [RFC5880].
  This experiment is intended to provide additional insights into what
  happens when the optimized authentication method defined in this
  document is used.  Here are the reasons why this document is on the
  Experimental track:

  *  In the initial stages of the document, there were significant
      participation and reviews from the working group.  Since then,
      there has been considerable changes to the document, e.g. the use
      of ISAAC, allowing for ISAAC bootstrapping when a BFD session
      comes up and use of a single Auth Type to indicate use of
      optimized authentication etc.  These changes did not get
      significant review from the working group and therefore does not
      meet the bar set in Section 4.1.1 of [RFC2026]

  *  There are no known implementations (even proof-of-concept) or
      implementation plans.  As a result, we do not currently know if
      there will be interop issues with legacy implementations or what
      exactly are the performance benefits of the optimization method.

  *  The work in this document could become very valuable in the
      future, especially if the need for deploying BFD authentication at
      scale becomes a reality.

    Do all Datatracker state attributes correctly reflect this intent?
Yes.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]?
Yes.

    To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.
Yes: https://mailarchive.ietf.org/arch/msg/rtg-bfd/tB3E6nl6N4w7wGIPMXsDF2gDdiE/

13. Has each author, editor, and contributor shown their willingness to be
    listed as such?
Yes.

    If the total number of authors and editors on the front page
    is greater than five, please provide a justification.
N/A.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)
  Miscellaneous warnings:
  ----------------------------------------------------------------------------

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

    (The document does seem to have the reference to RFC 2119 which the
    ID-Checklist requires).
  -- The document date (16 April 2025) is 18 days in the past.  Is this
    intentional?

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].
No.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?
N/A

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.
No.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?
No. Note that this document should be in the same bundle as draft-ietf-bfd-secure-sequence-numbers and draft-ietf-bfd-stability (which are updated in "locked-step" with this document).

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.
No. This is an experimental document.

20. Describe the document shepherd's review of the IANA considerations section,
    especially with regard to its consistency with the body of the document.
    Confirm that all aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).
Section 6 matches the rest of the document and confirming the above where applicable.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.
Assignment from the “BFD Authentication Types” registry requires Expert review. Checked https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml
There is also an updated IANA YANG module in the appendix.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://wiki.ietf.org/group/ops/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://wiki.ietf.org/group/iesg/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

=======================================================================================

=======================================================================================
Update December 31st 2024 on draft-ietf-bfd-optimizing-authentication-21

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

Strong consensus of a few individuals.
The initial revision of this document is from 2015. Since then there have been multiple
discussions on the BFD alias and in in-person WG meetings. The "recent" changes to the
document to use ISAAC are the ones on which the WG has been mostly silent.

There has been opposition by one person (see 2 below).

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

There has been controversy because of the IPR Disclosure.
https://mailarchive.ietf.org/arch/msg/rtg-bfd/u8rvWwvDWRKI3jseGHecAB9WtDo/

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize the areas of conflict in separate email messages to the
  responsible Area Director. (It should be in a separate email because this
  questionnaire is publicly available.)

No

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

No implementations and no known plans to implement.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

No and no.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

The document has undergone a YANG Doctor review.

7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation?

Yes.

  If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time?

No errors.

  Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

Yes.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

YANG has been validated.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

The document is clearly written and nearly ready.
There are some comments to be addressed before the document is handed off to the responsible AD:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/ca_gCMOCyXGNhhTBAvg5lGLXJK8/

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

There has been a secdir review and comments have been addressed:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/303D-DZ2DVFr9frgy75b6yyiILk/

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])?

Experimental as indicated on title page.

    Why is this the proper type
    of RFC?
Main reasons:
- No known implementations
- Not a lot of reviews on the latest revisions of the document

    Do all Datatracker state attributes correctly reflect this intent?
Yes.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]?
Yes.

    To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.
Waiting for response from 1 co-author.


13. Has each author, editor, and contributor shown their willingness to be
    listed as such?
Yes.

    If the total number of authors and editors on the front page
    is greater than five, please provide a justification.
N/A.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)
  Miscellaneous warnings:
  ----------------------------------------------------------------------------

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

    (The document does seem to have the reference to RFC 2119 which the
    ID-Checklist requires).
  -- The document date (21 October 2024) is 71 days in the past.  Is this
    intentional?

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].
No.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?
N/A

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.
No.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?
No. Note that this document should be in the same bundle as draft-ietf-bfd-secure-sequence-numbers (which is updated in "locked-step" with this document).

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.
No. This is an experimental document.

20. Describe the document shepherd's review of the IANA considerations section,
    especially with regard to its consistency with the body of the document.
    Confirm that all aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).
Section 6 matches the rest of the document and confirming the above where applicable.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.
Assignment from the “BFD Authentication Types” registry requires Expert review. Checked https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml
There is also an updated IANA YANG module in the appendix.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://wiki.ietf.org/group/ops/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://wiki.ietf.org/group/iesg/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

=======================================================================================

Update Nov 23rd 2020

All comments have been addressed.

Update July 23rd 2020

Revised comments on draft-ietf-bfd-optimizing-authentication-10

General: both "BFD control packet" and "BFD packet" are used. I think we should stick to "BFD control packet".
General: s/BFD Control packet/BFD control packet/

Introduction, next-to last paragraph. Instead of "The interval of this non-state change frame can be...", I'd suggest "The interval of these BFD packets can be..." or "The interval of the BFD packets without a significant change can be...". Anyway remove "frame" as previously discussed and avoid use of "non-state change" now that you've defined what a significant change is.

Section 1.2. The new table could be incorrectly interpreted as having 1 entry. Suggest changing this to bullet form would make it clearer.

Section 1.2 introduces the term "configured interval" but section 2 uses the term "configured period". Also for the description, what about "interval at which BFD control packets are authenticated in the UP state".
Also wondering if instead we should have a new bfd.AuthUpStateInterval state variable (see 6.8.1 of RFC5880) since having this value may not always be configured (implementation specific)?

Section 2. Replace  "frame" by "packet" or "BFD control packet"  as appropriate.

Section 2. Thanks for modifying the table as per our discussions. Regarding adding AdminDown to the table, I believe I misled you. Our discussion was based on "what happens if we're UP and receive a packet which says AdminDown"? As per 6.2 of RFC5880, the receiver would go to DOWN state. However the rows/columns in the table are for the local state (new and old), and not for state in received packet. Since we can't go to AdminDown state or leave AdmnDown state based on a packet received, AdminDown state should be removed from this table . I think it'd be good to add a reference to the BFD FSM (6.8.2 of RFC5880) in the paragraph before the table.

Section 2. For configured period (or whatever we decide to call it) add a reference to section 1.2.

Section 4. s/to to/to/

=============================================================

(1) What type of RFC is being requested (BCP, Proposed Standard, Internet Standard, Informational, Experimental, or Historic)? Why is this the proper type of RFC? Is this type of RFC indicated in the title page header?
Standards Track as indicated on title page.

(2) The IESG approval announcement includes a Document Announcement Write-Up. Please provide such a Document Announcement Write-Up. Recent examples can be found in the "Action" announcements for approved documents. The approval announcement contains the following sections:

Technical Summary:
This document describes an optimization to BFD Authentication as described in Section 6.7 of RFC5880. To remove the computational load on end-systems running BFD, it removes the requirement to authenticate all BFD control packets while providing a mechanism to keep the BFD sessions secure.

Relevant content can frequently be found in the abstract and/or introduction of the document. If not, this may be an indication that there are deficiencies in the abstract or introduction.

Working Group Summary:
Initial revision of the document is from  February 2015. Since then there have been many discussions on the mailing list and in-person at BFD WG meetings. The document has improved significantly based on the various suggestions. There is consistency on the technical content.

One action which has been postponed is updating the BFD YANG model to enable this functionality (requires a -bis of the BFD YANG document due to the new auth-type) 

There has been controversy because of the IPR Disclosure, see below.

Was there anything in WG process that is worth noting? For example, was there controversy about particular points or were there decisions where the consensus was particularly rough?

Document Quality:

Are there existing implementations of the protocol? Have a significant number of vendors indicated their plan to implement the specification? Are there any reviewers that merit special mention as having done a thorough review, e.g., one that resulted in important changes or a conclusion that the document had no substantive issues? If there was a MIB Doctor, YANG Doctor, Media Type or other expert review, what was its course (briefly)? In the case of a Media Type review, on what date was the request posted?

The document is well-written, concise and technically accurate, but requires some editorial changes before being forwarded to the IESG.


Personnel:

Who is the Document Shepherd?
Reshad Rahman, BFD co-chair.

Who is the Responsible Area Director?
Martin Vigoureux is the responsible AD.


(3) Briefly describe the review of this document that was performed by the Document Shepherd. If this version of the document is not ready for publication, please explain why the document is being forwarded to the IESG.
The shepherd has gone through the document, email archive and meeting minutes. Comments have been addressed.

(4) Does the document Shepherd have any concerns about the depth or breadth of the reviews that have been performed?
None.

(5) Do portions of the document need review from a particular or from broader perspective, e.g., security, operational complexity, AAA, DNS, DHCP, XML, or internationalization? If so, describe the review that took place.
This document was discussed with security experts. This led to draft-ietf-bfd-secure-numbers.


(6) Describe any specific concerns or issues that the Document Shepherd has with this document that the Responsible Area Director and/or the IESG should be aware of? For example, perhaps he or she is uncomfortable with certain parts of the document, or has concerns whether there really is a need for it. In any event, if the WG has discussed those issues and has indicated that it still wishes to advance the document, detail those concerns here.
None

(7) Has each author confirmed that any and all appropriate IPR disclosures required for full conformance with the provisions of BCP 78 and BCP 79 have already been filed. If not, explain why?
Yes

(8) Has an IPR disclosure been filed that references this document? If so, summarize any WG discussion and conclusion regarding the IPR disclosures.
https://datatracker.ietf.org/ipr/3328/
There has been controversy on the IPR disclosure on this document for 2 main reasons:
i) IPR disclosure was late (Nov 2018)
ii) The terms of the IPR
The IPR disclosure and terms were discussed at length on the mailing list and in the WG meetings:
https://datatracker.ietf.org/meeting/104/materials/minutes-104-bfd-00.pdf
https://datatracker.ietf.org/meeting/105/materials/minutes-105-bfd-02.pdf



(9) How solid is the WG consensus behind this document? Does it represent the strong concurrence of a few individuals, with others being silent, or does the WG as a whole understand and agree with it?
Solid consensus on the technical aspects.
There is known opposition from 1 person (because of the IPR Disclosure).
https://mailarchive.ietf.org/arch/msg/rtg-bfd/u8rvWwvDWRKI3jseGHecAB9WtDo/


(10) Has anyone threatened an appeal or otherwise indicated extreme discontent? If so, please summarise the areas of conflict in separate email messages to the Responsible Area Director. (It should be in a separate email because this questionnaire is publicly available.)
None

(11) Identify any ID nits the Document Shepherd has found in this document. (See http://www.ietf.org/tools/idnits/ and the Internet-Drafts Checklist). Boilerplate checks are not enough; this check needs to be thorough.
3 warnings:
  == The copyright year in the IETF Trust and authors Copyright Line does not
    match the current year

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

  == Outdated reference: A later version (-05) exists of
    draft-ietf-bfd-secure-sequence-numbers-04

Comment about document data being 186 days in the past.

(12) Describe how the document meets any required formal review criteria, such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.
N/A

(13) Have all references within this document been identified as either normative or informative?
Yes

(14) Are there normative references to documents that are not ready for advancement or are otherwise in an unclear state? If such normative references exist, what is the plan for their completion?
None

(15) Are there downward normative references references (see RFC 3967)? If so, list these downward references to support the Area Director in the Last Call procedure.
None

(16) Will publication of this document change the status of any existing RFCs? Are those RFCs listed on the title page header, listed in the abstract, and discussed in the introduction? If the RFCs are not listed in the Abstract and Introduction, explain why, and point to the part of the document where the relationship of this document to the other RFCs is discussed. If this information is not in the document, explain why the WG considers it unnecessary.
No

(17) Describe the Document Shepherd's review of the IANA considerations section, especially with regard to its consistency with the body of the document. Confirm that all protocol extensions that the document makes are associated with the appropriate reservations in IANA registries. Confirm that any referenced IANA registries have been clearly identified. Confirm that newly created IANA registries include a detailed specification of the initial contents for the registry, that allocations procedures for future registrations are defined, and a reasonable name for the new registry has been suggested (see RFC 8126).
Assignment from the “BFD Authentication Types” registry requires Expert review. Checked https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml

(18) List any new IANA registries that require Expert Review for future allocations. Provide any public guidance that the IESG would find useful in selecting the IANA Experts for these new registries.
None

(19) Describe reviews and automated checks performed by the Document Shepherd to validate sections of the document written in a formal language, such as XML code, BNF rules, MIB definitions, YANG modules, etc.
N/A

(20) If the document contains a YANG module, has the module been checked with any of the recommended validation tools (https://trac.ietf.org/trac/ops/wiki/yang-review-tools) for syntax and formatting validation? If there are any resulting errors or warnings, what is the justification for not fixing them at this time? Does the YANG module comply with the Network Management Datastore Architecture (NMDA) as specified in RFC8342?
N/A


COMMENTS

General:
• Updates RFC5880 missing from title page
• Replace BFD frames by BFD packets or BFD control packets. Don’t use frames since RFC5880 uses packets.
• Use of term Null-authentication TLV. RFC5880 uses authentication section, doesn’t mention auth TLV.

Abstract:
Mention that this document updates RFC5880.

Requirements Language
Please put this is a separate (sub)section later, e.g. after introduction.

Introduction
First paragraph: s/is computationally intensive process/is a computationally intensive process/
Split first sentence into 2, e.g.
  Authenticating every BFD [RFC5880] packet with a Simple Password, or
  with a MD5 Message-Digest Algorithm [RFC1321], or Secure Hash
  Algorithm (SHA-1) algorithms is a computationally intensive process.
  This makes it difficult, if not impossible, to authenticate every packet,
  particularly at faster rates.

2nd paragraph: “… only BFD frames that signal a state change in BFD be authenticated.” State change is not 100% correct since P/F/D bit changes aren’t state changes (as mentioned in more detail below in section 2 comments). What about this instead: “State change, a demand mode change (to D bit) or a poll sequence change (P or F bit change) in a BFD packet are categorized as a significant BFD change. This document proposes that all BFD control packets which signal a significant BFD change MUST be authenticated if the session’s bfd.AuthType is non-zero. Other BFD control packets MAY be transmitted and received without the A bit set.” If you do use “significant BFD change”, add it to terminology section.
s/non-state change frame/BFD control packets without state or D/F/P bit change/, e.g.
“To detect a Man In the Middle (MITM) attack, it is also proposed that BFD control packets without a significant change be authenticated occasionally.  The interval of these control packets…”

Section 2
POLL and DEMAND are NOT strictly states. POLL refers to “Poll sequence” as specified in section 6.5 of RFC5880. DEMAND refers to “Demand mode” as specified in section 6.6 of RFC5880. In the table, the POLL entry refers to polling sequence enabled and in any BFD state. Likewise, the DEMAND entry refers to Demand mode. This means that a session in UP state, in demand mode and polling sequence enabled will match 3 entries in that table. It’s a bit confusing. Here’s what I suggest instead:
1. Take POLL out of the table. Add a paragraph mentioning that if P or F bit changes value, the packet MUST be authenticated
2. Take DEMAND out of the table. Add a paragraph mentioning that if D bit changes value, the packet MUST be authenticated

Another comment on the table. The text says it should be read as state change from column to row. Column INIT to row UP is n/a whereas column UP to row INIT is Auth. INIT to UP is a valid transition, UP to INIT is not (has to go through DOWN first). So I think those entries should be reversed in the table.

Last paragraph: CC frames is not defined in BFD, use “control packets” instead?

Section 3
Sequence number mentions “as defined in [RFC5880]”. Suggest mentioning bfd.XmitAuthSeq

Security Considerations.
I believe this needs to be beefed up:
1) Use of sequence number for non-authenticated frames. Secure sequence numbers even better.
2) Mention (again) that non-authenticated BFD packets which have a significant change (state, D/F/P) are dropped. So if someone injects a non-authenticated packet with Down state to take down the session, that won’t work.

Section 6.2
RFC5880 should be a normative reference.

=======================================================================================
Update May 4th 2025 on draft-ietf-bfd-optimizing-authentication-24
Update for 2) on May 22nd 2025

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

Strong consensus of a few individuals.
The initial revision of this document is from 2015. Since then there have been multiple
discussions on the BFD alias and in in-person WG meetings. The "recent" changes to the
document to use ISAAC are the ones on which the WG has been mostly silent.

There has been opposition by one person (see 2 below).

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

There has been controversy because of the IPR Disclosure.
https://mailarchive.ietf.org/arch/msg/rtg-bfd/u8rvWwvDWRKI3jseGHecAB9WtDo/

However the authors have expressed that since the patent as filed, the document has diverged from what was filed:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/LFI1DvUHBUFBjz5Yxgvs4u6_2XU/
https://mailarchive.ietf.org/arch/msg/rtg-bfd/KpT0VQoLiExRzvzYe1DwL9JkJ4U/

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize the areas of conflict in separate email messages to the
  responsible Area Director. (It should be in a separate email because this
  questionnaire is publicly available.)

No

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

No implementations and no known plans to implement.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

No and no.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

The document has undergone a YANG Doctor review.

The authors have addressed all the comments.


7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation?

Yes.

  If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time?

No errors and no warnings.

  Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

Yes.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

YANG has been validated.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

The document is clearly written and nearly ready.

The authors have addressed all review comments.
https://mailarchive.ietf.org/arch/msg/rtg-bfd/ca_gCMOCyXGNhhTBAvg5lGLXJK8/

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

There has been a secdir review and comments have been addressed:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/303D-DZ2DVFr9frgy75b6yyiILk/

No comments from RtgDir review:
https://mailarchive.ietf.org/arch/msg/rtg-dir/El6oDoBT6r40I9IWC-YdJNEiPPM/

Comments from opsdir review have been addressed:
https://mailarchive.ietf.org/arch/msg/ops-dir/xJiWAeDtJFSdwUSpOnztZjgXwZw/

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])?

Experimental as indicated on title page.

    Why is this the proper type
    of RFC?

  This document describes an experimental update to BFD [RFC5880].
  This experiment is intended to provide additional insights into what
  happens when the optimized authentication method defined in this
  document is used.  Here are the reasons why this document is on the
  Experimental track:

  *  In the initial stages of the document, there were significant
      participation and reviews from the working group.  Since then,
      there has been considerable changes to the document, e.g. the use
      of ISAAC, allowing for ISAAC bootstrapping when a BFD session
      comes up and use of a single Auth Type to indicate use of
      optimized authentication etc.  These changes did not get
      significant review from the working group and therefore does not
      meet the bar set in Section 4.1.1 of [RFC2026]

  *  There are no known implementations (even proof-of-concept) or
      implementation plans.  As a result, we do not currently know if
      there will be interop issues with legacy implementations or what
      exactly are the performance benefits of the optimization method.

  *  The work in this document could become very valuable in the
      future, especially if the need for deploying BFD authentication at
      scale becomes a reality.

    Do all Datatracker state attributes correctly reflect this intent?
Yes.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]?
Yes.

    To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.
Yes: https://mailarchive.ietf.org/arch/msg/rtg-bfd/tB3E6nl6N4w7wGIPMXsDF2gDdiE/

13. Has each author, editor, and contributor shown their willingness to be
    listed as such?
Yes.

    If the total number of authors and editors on the front page
    is greater than five, please provide a justification.
N/A.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)
  Miscellaneous warnings:
  ----------------------------------------------------------------------------

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

    (The document does seem to have the reference to RFC 2119 which the
    ID-Checklist requires).
  -- The document date (16 April 2025) is 18 days in the past.  Is this
    intentional?

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].
No.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?
N/A

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.
No.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?
No. Note that this document should be in the same bundle as draft-ietf-bfd-secure-sequence-numbers and draft-ietf-bfd-stability (which are updated in "locked-step" with this document).

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.
No. This is an experimental document.

20. Describe the document shepherd's review of the IANA considerations section,
    especially with regard to its consistency with the body of the document.
    Confirm that all aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).
Section 6 matches the rest of the document and confirming the above where applicable.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.
Assignment from the “BFD Authentication Types” registry requires Expert review. Checked https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml
There is also an updated IANA YANG module in the appendix.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://wiki.ietf.org/group/ops/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://wiki.ietf.org/group/iesg/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

=======================================================================================

=======================================================================================
Update December 31st 2024 on draft-ietf-bfd-optimizing-authentication-21

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

Strong consensus of a few individuals.
The initial revision of this document is from 2015. Since then there have been multiple
discussions on the BFD alias and in in-person WG meetings. The "recent" changes to the
document to use ISAAC are the ones on which the WG has been mostly silent.

There has been opposition by one person (see 2 below).

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

There has been controversy because of the IPR Disclosure.
https://mailarchive.ietf.org/arch/msg/rtg-bfd/u8rvWwvDWRKI3jseGHecAB9WtDo/

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize the areas of conflict in separate email messages to the
  responsible Area Director. (It should be in a separate email because this
  questionnaire is publicly available.)

No

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

No implementations and no known plans to implement.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

No and no.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

The document has undergone a YANG Doctor review.

7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation?

Yes.

  If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time?

No errors.

  Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

Yes.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

YANG has been validated.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

The document is clearly written and nearly ready.
There are some comments to be addressed before the document is handed off to the responsible AD:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/ca_gCMOCyXGNhhTBAvg5lGLXJK8/

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

There has been a secdir review and comments have been addressed:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/303D-DZ2DVFr9frgy75b6yyiILk/

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])?

Experimental as indicated on title page.

    Why is this the proper type
    of RFC?
Main reasons:
- No known implementations
- Not a lot of reviews on the latest revisions of the document

    Do all Datatracker state attributes correctly reflect this intent?
Yes.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]?
Yes.

    To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.
Waiting for response from 1 co-author.


13. Has each author, editor, and contributor shown their willingness to be
    listed as such?
Yes.

    If the total number of authors and editors on the front page
    is greater than five, please provide a justification.
N/A.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)
  Miscellaneous warnings:
  ----------------------------------------------------------------------------

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

    (The document does seem to have the reference to RFC 2119 which the
    ID-Checklist requires).
  -- The document date (21 October 2024) is 71 days in the past.  Is this
    intentional?

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].
No.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?
N/A

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.
No.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?
No. Note that this document should be in the same bundle as draft-ietf-bfd-secure-sequence-numbers (which is updated in "locked-step" with this document).

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.
No. This is an experimental document.

20. Describe the document shepherd's review of the IANA considerations section,
    especially with regard to its consistency with the body of the document.
    Confirm that all aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).
Section 6 matches the rest of the document and confirming the above where applicable.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.
Assignment from the “BFD Authentication Types” registry requires Expert review. Checked https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml
There is also an updated IANA YANG module in the appendix.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://wiki.ietf.org/group/ops/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://wiki.ietf.org/group/iesg/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

=======================================================================================

Update Nov 23rd 2020

All comments have been addressed.

Update July 23rd 2020

Revised comments on draft-ietf-bfd-optimizing-authentication-10

General: both "BFD control packet" and "BFD packet" are used. I think we should stick to "BFD control packet".
General: s/BFD Control packet/BFD control packet/

Introduction, next-to last paragraph. Instead of "The interval of this non-state change frame can be...", I'd suggest "The interval of these BFD packets can be..." or "The interval of the BFD packets without a significant change can be...". Anyway remove "frame" as previously discussed and avoid use of "non-state change" now that you've defined what a significant change is.

Section 1.2. The new table could be incorrectly interpreted as having 1 entry. Suggest changing this to bullet form would make it clearer.

Section 1.2 introduces the term "configured interval" but section 2 uses the term "configured period". Also for the description, what about "interval at which BFD control packets are authenticated in the UP state".
Also wondering if instead we should have a new bfd.AuthUpStateInterval state variable (see 6.8.1 of RFC5880) since having this value may not always be configured (implementation specific)?

Section 2. Replace  "frame" by "packet" or "BFD control packet"  as appropriate.

Section 2. Thanks for modifying the table as per our discussions. Regarding adding AdminDown to the table, I believe I misled you. Our discussion was based on "what happens if we're UP and receive a packet which says AdminDown"? As per 6.2 of RFC5880, the receiver would go to DOWN state. However the rows/columns in the table are for the local state (new and old), and not for state in received packet. Since we can't go to AdminDown state or leave AdmnDown state based on a packet received, AdminDown state should be removed from this table . I think it'd be good to add a reference to the BFD FSM (6.8.2 of RFC5880) in the paragraph before the table.

Section 2. For configured period (or whatever we decide to call it) add a reference to section 1.2.

Section 4. s/to to/to/

=============================================================

(1) What type of RFC is being requested (BCP, Proposed Standard, Internet Standard, Informational, Experimental, or Historic)? Why is this the proper type of RFC? Is this type of RFC indicated in the title page header?
Standards Track as indicated on title page.

(2) The IESG approval announcement includes a Document Announcement Write-Up. Please provide such a Document Announcement Write-Up. Recent examples can be found in the "Action" announcements for approved documents. The approval announcement contains the following sections:

Technical Summary:
This document describes an optimization to BFD Authentication as described in Section 6.7 of RFC5880. To remove the computational load on end-systems running BFD, it removes the requirement to authenticate all BFD control packets while providing a mechanism to keep the BFD sessions secure.

Relevant content can frequently be found in the abstract and/or introduction of the document. If not, this may be an indication that there are deficiencies in the abstract or introduction.

Working Group Summary:
Initial revision of the document is from  February 2015. Since then there have been many discussions on the mailing list and in-person at BFD WG meetings. The document has improved significantly based on the various suggestions. There is consistency on the technical content.

One action which has been postponed is updating the BFD YANG model to enable this functionality (requires a -bis of the BFD YANG document due to the new auth-type) 

There has been controversy because of the IPR Disclosure, see below.

Was there anything in WG process that is worth noting? For example, was there controversy about particular points or were there decisions where the consensus was particularly rough?

Document Quality:

Are there existing implementations of the protocol? Have a significant number of vendors indicated their plan to implement the specification? Are there any reviewers that merit special mention as having done a thorough review, e.g., one that resulted in important changes or a conclusion that the document had no substantive issues? If there was a MIB Doctor, YANG Doctor, Media Type or other expert review, what was its course (briefly)? In the case of a Media Type review, on what date was the request posted?

The document is well-written, concise and technically accurate, but requires some editorial changes before being forwarded to the IESG.


Personnel:

Who is the Document Shepherd?
Reshad Rahman, BFD co-chair.

Who is the Responsible Area Director?
Martin Vigoureux is the responsible AD.


(3) Briefly describe the review of this document that was performed by the Document Shepherd. If this version of the document is not ready for publication, please explain why the document is being forwarded to the IESG.
The shepherd has gone through the document, email archive and meeting minutes. Comments have been addressed.

(4) Does the document Shepherd have any concerns about the depth or breadth of the reviews that have been performed?
None.

(5) Do portions of the document need review from a particular or from broader perspective, e.g., security, operational complexity, AAA, DNS, DHCP, XML, or internationalization? If so, describe the review that took place.
This document was discussed with security experts. This led to draft-ietf-bfd-secure-numbers.


(6) Describe any specific concerns or issues that the Document Shepherd has with this document that the Responsible Area Director and/or the IESG should be aware of? For example, perhaps he or she is uncomfortable with certain parts of the document, or has concerns whether there really is a need for it. In any event, if the WG has discussed those issues and has indicated that it still wishes to advance the document, detail those concerns here.
None

(7) Has each author confirmed that any and all appropriate IPR disclosures required for full conformance with the provisions of BCP 78 and BCP 79 have already been filed. If not, explain why?
Yes

(8) Has an IPR disclosure been filed that references this document? If so, summarize any WG discussion and conclusion regarding the IPR disclosures.
https://datatracker.ietf.org/ipr/3328/
There has been controversy on the IPR disclosure on this document for 2 main reasons:
i) IPR disclosure was late (Nov 2018)
ii) The terms of the IPR
The IPR disclosure and terms were discussed at length on the mailing list and in the WG meetings:
https://datatracker.ietf.org/meeting/104/materials/minutes-104-bfd-00.pdf
https://datatracker.ietf.org/meeting/105/materials/minutes-105-bfd-02.pdf



(9) How solid is the WG consensus behind this document? Does it represent the strong concurrence of a few individuals, with others being silent, or does the WG as a whole understand and agree with it?
Solid consensus on the technical aspects.
There is known opposition from 1 person (because of the IPR Disclosure).
https://mailarchive.ietf.org/arch/msg/rtg-bfd/u8rvWwvDWRKI3jseGHecAB9WtDo/


(10) Has anyone threatened an appeal or otherwise indicated extreme discontent? If so, please summarise the areas of conflict in separate email messages to the Responsible Area Director. (It should be in a separate email because this questionnaire is publicly available.)
None

(11) Identify any ID nits the Document Shepherd has found in this document. (See http://www.ietf.org/tools/idnits/ and the Internet-Drafts Checklist). Boilerplate checks are not enough; this check needs to be thorough.
3 warnings:
  == The copyright year in the IETF Trust and authors Copyright Line does not
    match the current year

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

  == Outdated reference: A later version (-05) exists of
    draft-ietf-bfd-secure-sequence-numbers-04

Comment about document data being 186 days in the past.

(12) Describe how the document meets any required formal review criteria, such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.
N/A

(13) Have all references within this document been identified as either normative or informative?
Yes

(14) Are there normative references to documents that are not ready for advancement or are otherwise in an unclear state? If such normative references exist, what is the plan for their completion?
None

(15) Are there downward normative references references (see RFC 3967)? If so, list these downward references to support the Area Director in the Last Call procedure.
None

(16) Will publication of this document change the status of any existing RFCs? Are those RFCs listed on the title page header, listed in the abstract, and discussed in the introduction? If the RFCs are not listed in the Abstract and Introduction, explain why, and point to the part of the document where the relationship of this document to the other RFCs is discussed. If this information is not in the document, explain why the WG considers it unnecessary.
No

(17) Describe the Document Shepherd's review of the IANA considerations section, especially with regard to its consistency with the body of the document. Confirm that all protocol extensions that the document makes are associated with the appropriate reservations in IANA registries. Confirm that any referenced IANA registries have been clearly identified. Confirm that newly created IANA registries include a detailed specification of the initial contents for the registry, that allocations procedures for future registrations are defined, and a reasonable name for the new registry has been suggested (see RFC 8126).
Assignment from the “BFD Authentication Types” registry requires Expert review. Checked https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml

(18) List any new IANA registries that require Expert Review for future allocations. Provide any public guidance that the IESG would find useful in selecting the IANA Experts for these new registries.
None

(19) Describe reviews and automated checks performed by the Document Shepherd to validate sections of the document written in a formal language, such as XML code, BNF rules, MIB definitions, YANG modules, etc.
N/A

(20) If the document contains a YANG module, has the module been checked with any of the recommended validation tools (https://trac.ietf.org/trac/ops/wiki/yang-review-tools) for syntax and formatting validation? If there are any resulting errors or warnings, what is the justification for not fixing them at this time? Does the YANG module comply with the Network Management Datastore Architecture (NMDA) as specified in RFC8342?
N/A


COMMENTS

General:
• Updates RFC5880 missing from title page
• Replace BFD frames by BFD packets or BFD control packets. Don’t use frames since RFC5880 uses packets.
• Use of term Null-authentication TLV. RFC5880 uses authentication section, doesn’t mention auth TLV.

Abstract:
Mention that this document updates RFC5880.

Requirements Language
Please put this is a separate (sub)section later, e.g. after introduction.

Introduction
First paragraph: s/is computationally intensive process/is a computationally intensive process/
Split first sentence into 2, e.g.
  Authenticating every BFD [RFC5880] packet with a Simple Password, or
  with a MD5 Message-Digest Algorithm [RFC1321], or Secure Hash
  Algorithm (SHA-1) algorithms is a computationally intensive process.
  This makes it difficult, if not impossible, to authenticate every packet,
  particularly at faster rates.

2nd paragraph: “… only BFD frames that signal a state change in BFD be authenticated.” State change is not 100% correct since P/F/D bit changes aren’t state changes (as mentioned in more detail below in section 2 comments). What about this instead: “State change, a demand mode change (to D bit) or a poll sequence change (P or F bit change) in a BFD packet are categorized as a significant BFD change. This document proposes that all BFD control packets which signal a significant BFD change MUST be authenticated if the session’s bfd.AuthType is non-zero. Other BFD control packets MAY be transmitted and received without the A bit set.” If you do use “significant BFD change”, add it to terminology section.
s/non-state change frame/BFD control packets without state or D/F/P bit change/, e.g.
“To detect a Man In the Middle (MITM) attack, it is also proposed that BFD control packets without a significant change be authenticated occasionally.  The interval of these control packets…”

Section 2
POLL and DEMAND are NOT strictly states. POLL refers to “Poll sequence” as specified in section 6.5 of RFC5880. DEMAND refers to “Demand mode” as specified in section 6.6 of RFC5880. In the table, the POLL entry refers to polling sequence enabled and in any BFD state. Likewise, the DEMAND entry refers to Demand mode. This means that a session in UP state, in demand mode and polling sequence enabled will match 3 entries in that table. It’s a bit confusing. Here’s what I suggest instead:
1. Take POLL out of the table. Add a paragraph mentioning that if P or F bit changes value, the packet MUST be authenticated
2. Take DEMAND out of the table. Add a paragraph mentioning that if D bit changes value, the packet MUST be authenticated

Another comment on the table. The text says it should be read as state change from column to row. Column INIT to row UP is n/a whereas column UP to row INIT is Auth. INIT to UP is a valid transition, UP to INIT is not (has to go through DOWN first). So I think those entries should be reversed in the table.

Last paragraph: CC frames is not defined in BFD, use “control packets” instead?

Section 3
Sequence number mentions “as defined in [RFC5880]”. Suggest mentioning bfd.XmitAuthSeq

Security Considerations.
I believe this needs to be beefed up:
1) Use of sequence number for non-authenticated frames. Secure sequence numbers even better.
2) Mention (again) that non-authenticated BFD packets which have a significant change (state, D/F/P) are dropped. So if someone injects a non-authenticated packet with Down state to take down the session, that won’t work.

Section 6.2
RFC5880 should be a normative reference.

=======================================================================================
Update May 4th 2025 on draft-ietf-bfd-optimizing-authentication-24

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

Strong consensus of a few individuals.
The initial revision of this document is from 2015. Since then there have been multiple
discussions on the BFD alias and in in-person WG meetings. The "recent" changes to the
document to use ISAAC are the ones on which the WG has been mostly silent.

There has been opposition by one person (see 2 below).

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

There has been controversy because of the IPR Disclosure.
https://mailarchive.ietf.org/arch/msg/rtg-bfd/u8rvWwvDWRKI3jseGHecAB9WtDo/

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize the areas of conflict in separate email messages to the
  responsible Area Director. (It should be in a separate email because this
  questionnaire is publicly available.)

No

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

No implementations and no known plans to implement.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

No and no.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

The document has undergone a YANG Doctor review.

The authors have addressed all the comments.


7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation?

Yes.

  If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time?

No errors and no warnings.

  Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

Yes.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

YANG has been validated.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

The document is clearly written and nearly ready.

The authors have addressed all review comments.
https://mailarchive.ietf.org/arch/msg/rtg-bfd/ca_gCMOCyXGNhhTBAvg5lGLXJK8/

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

There has been a secdir review and comments have been addressed:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/303D-DZ2DVFr9frgy75b6yyiILk/

No comments from RtgDir review:
https://mailarchive.ietf.org/arch/msg/rtg-dir/El6oDoBT6r40I9IWC-YdJNEiPPM/

Comments from opsdir review have been addressed:
https://mailarchive.ietf.org/arch/msg/ops-dir/xJiWAeDtJFSdwUSpOnztZjgXwZw/

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])?

Experimental as indicated on title page.

    Why is this the proper type
    of RFC?

  This document describes an experimental update to BFD [RFC5880].
  This experiment is intended to provide additional insights into what
  happens when the optimized authentication method defined in this
  document is used.  Here are the reasons why this document is on the
  Experimental track:

  *  In the initial stages of the document, there were significant
      participation and reviews from the working group.  Since then,
      there has been considerable changes to the document, e.g. the use
      of ISAAC, allowing for ISAAC bootstrapping when a BFD session
      comes up and use of a single Auth Type to indicate use of
      optimized authentication etc.  These changes did not get
      significant review from the working group and therefore does not
      meet the bar set in Section 4.1.1 of [RFC2026]

  *  There are no known implementations (even proof-of-concept) or
      implementation plans.  As a result, we do not currently know if
      there will be interop issues with legacy implementations or what
      exactly are the performance benefits of the optimization method.

  *  The work in this document could become very valuable in the
      future, especially if the need for deploying BFD authentication at
      scale becomes a reality.

    Do all Datatracker state attributes correctly reflect this intent?
Yes.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]?
Yes.

    To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.
Yes: https://mailarchive.ietf.org/arch/msg/rtg-bfd/tB3E6nl6N4w7wGIPMXsDF2gDdiE/

13. Has each author, editor, and contributor shown their willingness to be
    listed as such?
Yes.

    If the total number of authors and editors on the front page
    is greater than five, please provide a justification.
N/A.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)
  Miscellaneous warnings:
  ----------------------------------------------------------------------------

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

    (The document does seem to have the reference to RFC 2119 which the
    ID-Checklist requires).
  -- The document date (16 April 2025) is 18 days in the past.  Is this
    intentional?

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].
No.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?
N/A

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.
No.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?
No. Note that this document should be in the same bundle as draft-ietf-bfd-secure-sequence-numbers and draft-ietf-bfd-stability (which are updated in "locked-step" with this document).

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.
No. This is an experimental document.

20. Describe the document shepherd's review of the IANA considerations section,
    especially with regard to its consistency with the body of the document.
    Confirm that all aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).
Section 6 matches the rest of the document and confirming the above where applicable.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.
Assignment from the “BFD Authentication Types” registry requires Expert review. Checked https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml
There is also an updated IANA YANG module in the appendix.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://wiki.ietf.org/group/ops/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://wiki.ietf.org/group/iesg/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

=======================================================================================

=======================================================================================
Update December 31st 2024 on draft-ietf-bfd-optimizing-authentication-21

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

Strong consensus of a few individuals.
The initial revision of this document is from 2015. Since then there have been multiple
discussions on the BFD alias and in in-person WG meetings. The "recent" changes to the
document to use ISAAC are the ones on which the WG has been mostly silent.

There has been opposition by one person (see 2 below).

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

There has been controversy because of the IPR Disclosure.
https://mailarchive.ietf.org/arch/msg/rtg-bfd/u8rvWwvDWRKI3jseGHecAB9WtDo/

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize the areas of conflict in separate email messages to the
  responsible Area Director. (It should be in a separate email because this
  questionnaire is publicly available.)

No

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

No implementations and no known plans to implement.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

No and no.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

The document has undergone a YANG Doctor review.

7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation?

Yes.

  If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time?

No errors.

  Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

Yes.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

YANG has been validated.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

The document is clearly written and nearly ready.
There are some comments to be addressed before the document is handed off to the responsible AD:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/ca_gCMOCyXGNhhTBAvg5lGLXJK8/

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

There has been a secdir review and comments have been addressed:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/303D-DZ2DVFr9frgy75b6yyiILk/

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])?

Experimental as indicated on title page.

    Why is this the proper type
    of RFC?
Main reasons:
- No known implementations
- Not a lot of reviews on the latest revisions of the document

    Do all Datatracker state attributes correctly reflect this intent?
Yes.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]?
Yes.

    To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.
Waiting for response from 1 co-author.


13. Has each author, editor, and contributor shown their willingness to be
    listed as such?
Yes.

    If the total number of authors and editors on the front page
    is greater than five, please provide a justification.
N/A.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)
  Miscellaneous warnings:
  ----------------------------------------------------------------------------

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

    (The document does seem to have the reference to RFC 2119 which the
    ID-Checklist requires).
  -- The document date (21 October 2024) is 71 days in the past.  Is this
    intentional?

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].
No.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?
N/A

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.
No.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?
No. Note that this document should be in the same bundle as draft-ietf-bfd-secure-sequence-numbers (which is updated in "locked-step" with this document).

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.
No. This is an experimental document.

20. Describe the document shepherd's review of the IANA considerations section,
    especially with regard to its consistency with the body of the document.
    Confirm that all aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).
Section 6 matches the rest of the document and confirming the above where applicable.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.
Assignment from the “BFD Authentication Types” registry requires Expert review. Checked https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml
There is also an updated IANA YANG module in the appendix.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://wiki.ietf.org/group/ops/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://wiki.ietf.org/group/iesg/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

=======================================================================================

Update Nov 23rd 2020

All comments have been addressed.

Update July 23rd 2020

Revised comments on draft-ietf-bfd-optimizing-authentication-10

General: both "BFD control packet" and "BFD packet" are used. I think we should stick to "BFD control packet".
General: s/BFD Control packet/BFD control packet/

Introduction, next-to last paragraph. Instead of "The interval of this non-state change frame can be...", I'd suggest "The interval of these BFD packets can be..." or "The interval of the BFD packets without a significant change can be...". Anyway remove "frame" as previously discussed and avoid use of "non-state change" now that you've defined what a significant change is.

Section 1.2. The new table could be incorrectly interpreted as having 1 entry. Suggest changing this to bullet form would make it clearer.

Section 1.2 introduces the term "configured interval" but section 2 uses the term "configured period". Also for the description, what about "interval at which BFD control packets are authenticated in the UP state".
Also wondering if instead we should have a new bfd.AuthUpStateInterval state variable (see 6.8.1 of RFC5880) since having this value may not always be configured (implementation specific)?

Section 2. Replace  "frame" by "packet" or "BFD control packet"  as appropriate.

Section 2. Thanks for modifying the table as per our discussions. Regarding adding AdminDown to the table, I believe I misled you. Our discussion was based on "what happens if we're UP and receive a packet which says AdminDown"? As per 6.2 of RFC5880, the receiver would go to DOWN state. However the rows/columns in the table are for the local state (new and old), and not for state in received packet. Since we can't go to AdminDown state or leave AdmnDown state based on a packet received, AdminDown state should be removed from this table . I think it'd be good to add a reference to the BFD FSM (6.8.2 of RFC5880) in the paragraph before the table.

Section 2. For configured period (or whatever we decide to call it) add a reference to section 1.2.

Section 4. s/to to/to/

=============================================================

(1) What type of RFC is being requested (BCP, Proposed Standard, Internet Standard, Informational, Experimental, or Historic)? Why is this the proper type of RFC? Is this type of RFC indicated in the title page header?
Standards Track as indicated on title page.

(2) The IESG approval announcement includes a Document Announcement Write-Up. Please provide such a Document Announcement Write-Up. Recent examples can be found in the "Action" announcements for approved documents. The approval announcement contains the following sections:

Technical Summary:
This document describes an optimization to BFD Authentication as described in Section 6.7 of RFC5880. To remove the computational load on end-systems running BFD, it removes the requirement to authenticate all BFD control packets while providing a mechanism to keep the BFD sessions secure.

Relevant content can frequently be found in the abstract and/or introduction of the document. If not, this may be an indication that there are deficiencies in the abstract or introduction.

Working Group Summary:
Initial revision of the document is from  February 2015. Since then there have been many discussions on the mailing list and in-person at BFD WG meetings. The document has improved significantly based on the various suggestions. There is consistency on the technical content.

One action which has been postponed is updating the BFD YANG model to enable this functionality (requires a -bis of the BFD YANG document due to the new auth-type) 

There has been controversy because of the IPR Disclosure, see below.

Was there anything in WG process that is worth noting? For example, was there controversy about particular points or were there decisions where the consensus was particularly rough?

Document Quality:

Are there existing implementations of the protocol? Have a significant number of vendors indicated their plan to implement the specification? Are there any reviewers that merit special mention as having done a thorough review, e.g., one that resulted in important changes or a conclusion that the document had no substantive issues? If there was a MIB Doctor, YANG Doctor, Media Type or other expert review, what was its course (briefly)? In the case of a Media Type review, on what date was the request posted?

The document is well-written, concise and technically accurate, but requires some editorial changes before being forwarded to the IESG.


Personnel:

Who is the Document Shepherd?
Reshad Rahman, BFD co-chair.

Who is the Responsible Area Director?
Martin Vigoureux is the responsible AD.


(3) Briefly describe the review of this document that was performed by the Document Shepherd. If this version of the document is not ready for publication, please explain why the document is being forwarded to the IESG.
The shepherd has gone through the document, email archive and meeting minutes. Comments have been addressed.

(4) Does the document Shepherd have any concerns about the depth or breadth of the reviews that have been performed?
None.

(5) Do portions of the document need review from a particular or from broader perspective, e.g., security, operational complexity, AAA, DNS, DHCP, XML, or internationalization? If so, describe the review that took place.
This document was discussed with security experts. This led to draft-ietf-bfd-secure-numbers.


(6) Describe any specific concerns or issues that the Document Shepherd has with this document that the Responsible Area Director and/or the IESG should be aware of? For example, perhaps he or she is uncomfortable with certain parts of the document, or has concerns whether there really is a need for it. In any event, if the WG has discussed those issues and has indicated that it still wishes to advance the document, detail those concerns here.
None

(7) Has each author confirmed that any and all appropriate IPR disclosures required for full conformance with the provisions of BCP 78 and BCP 79 have already been filed. If not, explain why?
Yes

(8) Has an IPR disclosure been filed that references this document? If so, summarize any WG discussion and conclusion regarding the IPR disclosures.
https://datatracker.ietf.org/ipr/3328/
There has been controversy on the IPR disclosure on this document for 2 main reasons:
i) IPR disclosure was late (Nov 2018)
ii) The terms of the IPR
The IPR disclosure and terms were discussed at length on the mailing list and in the WG meetings:
https://datatracker.ietf.org/meeting/104/materials/minutes-104-bfd-00.pdf
https://datatracker.ietf.org/meeting/105/materials/minutes-105-bfd-02.pdf



(9) How solid is the WG consensus behind this document? Does it represent the strong concurrence of a few individuals, with others being silent, or does the WG as a whole understand and agree with it?
Solid consensus on the technical aspects.
There is known opposition from 1 person (because of the IPR Disclosure).
https://mailarchive.ietf.org/arch/msg/rtg-bfd/u8rvWwvDWRKI3jseGHecAB9WtDo/


(10) Has anyone threatened an appeal or otherwise indicated extreme discontent? If so, please summarise the areas of conflict in separate email messages to the Responsible Area Director. (It should be in a separate email because this questionnaire is publicly available.)
None

(11) Identify any ID nits the Document Shepherd has found in this document. (See http://www.ietf.org/tools/idnits/ and the Internet-Drafts Checklist). Boilerplate checks are not enough; this check needs to be thorough.
3 warnings:
  == The copyright year in the IETF Trust and authors Copyright Line does not
    match the current year

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

  == Outdated reference: A later version (-05) exists of
    draft-ietf-bfd-secure-sequence-numbers-04

Comment about document data being 186 days in the past.

(12) Describe how the document meets any required formal review criteria, such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.
N/A

(13) Have all references within this document been identified as either normative or informative?
Yes

(14) Are there normative references to documents that are not ready for advancement or are otherwise in an unclear state? If such normative references exist, what is the plan for their completion?
None

(15) Are there downward normative references references (see RFC 3967)? If so, list these downward references to support the Area Director in the Last Call procedure.
None

(16) Will publication of this document change the status of any existing RFCs? Are those RFCs listed on the title page header, listed in the abstract, and discussed in the introduction? If the RFCs are not listed in the Abstract and Introduction, explain why, and point to the part of the document where the relationship of this document to the other RFCs is discussed. If this information is not in the document, explain why the WG considers it unnecessary.
No

(17) Describe the Document Shepherd's review of the IANA considerations section, especially with regard to its consistency with the body of the document. Confirm that all protocol extensions that the document makes are associated with the appropriate reservations in IANA registries. Confirm that any referenced IANA registries have been clearly identified. Confirm that newly created IANA registries include a detailed specification of the initial contents for the registry, that allocations procedures for future registrations are defined, and a reasonable name for the new registry has been suggested (see RFC 8126).
Assignment from the “BFD Authentication Types” registry requires Expert review. Checked https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml

(18) List any new IANA registries that require Expert Review for future allocations. Provide any public guidance that the IESG would find useful in selecting the IANA Experts for these new registries.
None

(19) Describe reviews and automated checks performed by the Document Shepherd to validate sections of the document written in a formal language, such as XML code, BNF rules, MIB definitions, YANG modules, etc.
N/A

(20) If the document contains a YANG module, has the module been checked with any of the recommended validation tools (https://trac.ietf.org/trac/ops/wiki/yang-review-tools) for syntax and formatting validation? If there are any resulting errors or warnings, what is the justification for not fixing them at this time? Does the YANG module comply with the Network Management Datastore Architecture (NMDA) as specified in RFC8342?
N/A


COMMENTS

General:
• Updates RFC5880 missing from title page
• Replace BFD frames by BFD packets or BFD control packets. Don’t use frames since RFC5880 uses packets.
• Use of term Null-authentication TLV. RFC5880 uses authentication section, doesn’t mention auth TLV.

Abstract:
Mention that this document updates RFC5880.

Requirements Language
Please put this is a separate (sub)section later, e.g. after introduction.

Introduction
First paragraph: s/is computationally intensive process/is a computationally intensive process/
Split first sentence into 2, e.g.
  Authenticating every BFD [RFC5880] packet with a Simple Password, or
  with a MD5 Message-Digest Algorithm [RFC1321], or Secure Hash
  Algorithm (SHA-1) algorithms is a computationally intensive process.
  This makes it difficult, if not impossible, to authenticate every packet,
  particularly at faster rates.

2nd paragraph: “… only BFD frames that signal a state change in BFD be authenticated.” State change is not 100% correct since P/F/D bit changes aren’t state changes (as mentioned in more detail below in section 2 comments). What about this instead: “State change, a demand mode change (to D bit) or a poll sequence change (P or F bit change) in a BFD packet are categorized as a significant BFD change. This document proposes that all BFD control packets which signal a significant BFD change MUST be authenticated if the session’s bfd.AuthType is non-zero. Other BFD control packets MAY be transmitted and received without the A bit set.” If you do use “significant BFD change”, add it to terminology section.
s/non-state change frame/BFD control packets without state or D/F/P bit change/, e.g.
“To detect a Man In the Middle (MITM) attack, it is also proposed that BFD control packets without a significant change be authenticated occasionally.  The interval of these control packets…”

Section 2
POLL and DEMAND are NOT strictly states. POLL refers to “Poll sequence” as specified in section 6.5 of RFC5880. DEMAND refers to “Demand mode” as specified in section 6.6 of RFC5880. In the table, the POLL entry refers to polling sequence enabled and in any BFD state. Likewise, the DEMAND entry refers to Demand mode. This means that a session in UP state, in demand mode and polling sequence enabled will match 3 entries in that table. It’s a bit confusing. Here’s what I suggest instead:
1. Take POLL out of the table. Add a paragraph mentioning that if P or F bit changes value, the packet MUST be authenticated
2. Take DEMAND out of the table. Add a paragraph mentioning that if D bit changes value, the packet MUST be authenticated

Another comment on the table. The text says it should be read as state change from column to row. Column INIT to row UP is n/a whereas column UP to row INIT is Auth. INIT to UP is a valid transition, UP to INIT is not (has to go through DOWN first). So I think those entries should be reversed in the table.

Last paragraph: CC frames is not defined in BFD, use “control packets” instead?

Section 3
Sequence number mentions “as defined in [RFC5880]”. Suggest mentioning bfd.XmitAuthSeq

Security Considerations.
I believe this needs to be beefed up:
1) Use of sequence number for non-authenticated frames. Secure sequence numbers even better.
2) Mention (again) that non-authenticated BFD packets which have a significant change (state, D/F/P) are dropped. So if someone injects a non-authenticated packet with Down state to take down the session, that won’t work.

Section 6.2
RFC5880 should be a normative reference.

=======================================================================================
Update May 4th 2025 on draft-ietf-bfd-optimizing-authentication-24

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

Strong consensus of a few individuals.
The initial revision of this document is from 2015. Since then there have been multiple
discussions on the BFD alias and in in-person WG meetings. The "recent" changes to the
document to use ISAAC are the ones on which the WG has been mostly silent.

There has been opposition by one person (see 2 below).

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

There has been controversy because of the IPR Disclosure.
https://mailarchive.ietf.org/arch/msg/rtg-bfd/u8rvWwvDWRKI3jseGHecAB9WtDo/

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize the areas of conflict in separate email messages to the
  responsible Area Director. (It should be in a separate email because this
  questionnaire is publicly available.)

No

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

No implementations and no known plans to implement.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

No and no.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

The document has undergone a YANG Doctor review.

The authors have addressed all the comments.


7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation?

Yes.

  If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time?

No errors and no warnings.

  Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

Yes.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

YANG has been validated.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

The document is clearly written and nearly ready.

The authors have addressed all review comments.
https://mailarchive.ietf.org/arch/msg/rtg-bfd/ca_gCMOCyXGNhhTBAvg5lGLXJK8/

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

There has been a secdir review and comments have been addressed:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/303D-DZ2DVFr9frgy75b6yyiILk/

No comments from RtgDir review:
https://mailarchive.ietf.org/arch/msg/rtg-dir/El6oDoBT6r40I9IWC-YdJNEiPPM/

Comments from opsdir review have been addressed:
https://mailarchive.ietf.org/arch/msg/ops-dir/xJiWAeDtJFSdwUSpOnztZjgXwZw/

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])?

Experimental as indicated on title page.

    Why is this the proper type
    of RFC?

  This document describes an experimental update to BFD [RFC5880].
  This experiment is intended to provide additional insights into what
  happens when the optimized authentication method defined in this
  document is used.  Here are the reasons why this document is on the
  Experimental track:

  *  In the initial stages of the document, there were significant
      participation and reviews from the working group.  Since then,
      there has been considerable changes to the document, e.g. the use
      of ISAAC, allowing for ISAAC bootstrapping when a BFD session
      comes up and use of a single Auth Type to indicate use of
      optimized authentication etc.  These changes did not get
      significant review from the working group and therefore does not
      meet the bar set in Section 4.1.1 of [RFC2026]

  *  There are no known implementations (even proof-of-concept) or
      implementation plans.  As a result, we do not currently know if
      there will be interop issues with legacy implementations or what
      exactly are the performance benefits of the optimization method.

  *  The work in this document could become very valuable in the
      future, especially if the need for deploying BFD authentication at
      scale becomes a reality.

    Do all Datatracker state attributes correctly reflect this intent?
Yes.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]?
Yes.

    To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.
Yes: https://mailarchive.ietf.org/arch/msg/rtg-bfd/tB3E6nl6N4w7wGIPMXsDF2gDdiE/

13. Has each author, editor, and contributor shown their willingness to be
    listed as such?
Yes.

    If the total number of authors and editors on the front page
    is greater than five, please provide a justification.
N/A.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)
  Miscellaneous warnings:
  ----------------------------------------------------------------------------

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

    (The document does seem to have the reference to RFC 2119 which the
    ID-Checklist requires).
  -- The document date (16 April 2025) is 18 days in the past.  Is this
    intentional?

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].
No.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?
N/A

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.
No.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?
No. Note that this document should be in the same bundle as draft-ietf-bfd-secure-sequence-numbers and draft-ietf-bfd-stability (which are updated in "locked-step" with this document).

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.
No. This is an experimental document.

20. Describe the document shepherd's review of the IANA considerations section,
    especially with regard to its consistency with the body of the document.
    Confirm that all aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).
Section 6 matches the rest of the document and confirming the above where applicable.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.
Assignment from the “BFD Authentication Types” registry requires Expert review. Checked https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml
There is also an updated IANA YANG module in the appendix.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://wiki.ietf.org/group/ops/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://wiki.ietf.org/group/iesg/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

=======================================================================================

=======================================================================================
Update December 31st 2024 on draft-ietf-bfd-optimizing-authentication-21

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

Strong consensus of a few individuals.
The initial revision of this document is from 2015. Since then there have been multiple
discussions on the BFD alias and in in-person WG meetings. The "recent" changes to the
document to use ISAAC are the ones on which the WG has been mostly silent.

There has been opposition by one person (see 2 below).

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

There has been controversy because of the IPR Disclosure.
https://mailarchive.ietf.org/arch/msg/rtg-bfd/u8rvWwvDWRKI3jseGHecAB9WtDo/

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize the areas of conflict in separate email messages to the
  responsible Area Director. (It should be in a separate email because this
  questionnaire is publicly available.)

No

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

No implementations and no known plans to implement.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

No and no.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

The document has undergone a YANG Doctor review.

7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation?

Yes.

  If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time?

No errors.

  Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

Yes.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

YANG has been validated.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

The document is clearly written and nearly ready.
There are some comments to be addressed before the document is handed off to the responsible AD:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/ca_gCMOCyXGNhhTBAvg5lGLXJK8/

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

There has been a secdir review and comments have been addressed:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/303D-DZ2DVFr9frgy75b6yyiILk/

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])?

Experimental as indicated on title page.

    Why is this the proper type
    of RFC?
Main reasons:
- No known implementations
- Not a lot of reviews on the latest revisions of the document

    Do all Datatracker state attributes correctly reflect this intent?
Yes.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]?
Yes.

    To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.
Waiting for response from 1 co-author.


13. Has each author, editor, and contributor shown their willingness to be
    listed as such?
Yes.

    If the total number of authors and editors on the front page
    is greater than five, please provide a justification.
N/A.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)
  Miscellaneous warnings:
  ----------------------------------------------------------------------------

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

    (The document does seem to have the reference to RFC 2119 which the
    ID-Checklist requires).
  -- The document date (21 October 2024) is 71 days in the past.  Is this
    intentional?

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].
No.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?
N/A

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.
No.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?
No. Note that this document should be in the same bundle as draft-ietf-bfd-secure-sequence-numbers (which is updated in "locked-step" with this document).

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.
No. This is an experimental document.

20. Describe the document shepherd's review of the IANA considerations section,
    especially with regard to its consistency with the body of the document.
    Confirm that all aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).
Section 6 matches the rest of the document and confirming the above where applicable.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.
Assignment from the “BFD Authentication Types” registry requires Expert review. Checked https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml
There is also an updated IANA YANG module in the appendix.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://wiki.ietf.org/group/ops/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://wiki.ietf.org/group/iesg/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

=======================================================================================

Update Nov 23rd 2020

All comments have been addressed.

Update July 23rd 2020

Revised comments on draft-ietf-bfd-optimizing-authentication-10

General: both "BFD control packet" and "BFD packet" are used. I think we should stick to "BFD control packet".
General: s/BFD Control packet/BFD control packet/

Introduction, next-to last paragraph. Instead of "The interval of this non-state change frame can be...", I'd suggest "The interval of these BFD packets can be..." or "The interval of the BFD packets without a significant change can be...". Anyway remove "frame" as previously discussed and avoid use of "non-state change" now that you've defined what a significant change is.

Section 1.2. The new table could be incorrectly interpreted as having 1 entry. Suggest changing this to bullet form would make it clearer.

Section 1.2 introduces the term "configured interval" but section 2 uses the term "configured period". Also for the description, what about "interval at which BFD control packets are authenticated in the UP state".
Also wondering if instead we should have a new bfd.AuthUpStateInterval state variable (see 6.8.1 of RFC5880) since having this value may not always be configured (implementation specific)?

Section 2. Replace  "frame" by "packet" or "BFD control packet"  as appropriate.

Section 2. Thanks for modifying the table as per our discussions. Regarding adding AdminDown to the table, I believe I misled you. Our discussion was based on "what happens if we're UP and receive a packet which says AdminDown"? As per 6.2 of RFC5880, the receiver would go to DOWN state. However the rows/columns in the table are for the local state (new and old), and not for state in received packet. Since we can't go to AdminDown state or leave AdmnDown state based on a packet received, AdminDown state should be removed from this table . I think it'd be good to add a reference to the BFD FSM (6.8.2 of RFC5880) in the paragraph before the table.

Section 2. For configured period (or whatever we decide to call it) add a reference to section 1.2.

Section 4. s/to to/to/

=============================================================

(1) What type of RFC is being requested (BCP, Proposed Standard, Internet Standard, Informational, Experimental, or Historic)? Why is this the proper type of RFC? Is this type of RFC indicated in the title page header?
Standards Track as indicated on title page.

(2) The IESG approval announcement includes a Document Announcement Write-Up. Please provide such a Document Announcement Write-Up. Recent examples can be found in the "Action" announcements for approved documents. The approval announcement contains the following sections:

Technical Summary:
This document describes an optimization to BFD Authentication as described in Section 6.7 of RFC5880. To remove the computational load on end-systems running BFD, it removes the requirement to authenticate all BFD control packets while providing a mechanism to keep the BFD sessions secure.

Relevant content can frequently be found in the abstract and/or introduction of the document. If not, this may be an indication that there are deficiencies in the abstract or introduction.

Working Group Summary:
Initial revision of the document is from  February 2015. Since then there have been many discussions on the mailing list and in-person at BFD WG meetings. The document has improved significantly based on the various suggestions. There is consistency on the technical content.

One action which has been postponed is updating the BFD YANG model to enable this functionality (requires a -bis of the BFD YANG document due to the new auth-type) 

There has been controversy because of the IPR Disclosure, see below.

Was there anything in WG process that is worth noting? For example, was there controversy about particular points or were there decisions where the consensus was particularly rough?

Document Quality:

Are there existing implementations of the protocol? Have a significant number of vendors indicated their plan to implement the specification? Are there any reviewers that merit special mention as having done a thorough review, e.g., one that resulted in important changes or a conclusion that the document had no substantive issues? If there was a MIB Doctor, YANG Doctor, Media Type or other expert review, what was its course (briefly)? In the case of a Media Type review, on what date was the request posted?

The document is well-written, concise and technically accurate, but requires some editorial changes before being forwarded to the IESG.


Personnel:

Who is the Document Shepherd?
Reshad Rahman, BFD co-chair.

Who is the Responsible Area Director?
Martin Vigoureux is the responsible AD.


(3) Briefly describe the review of this document that was performed by the Document Shepherd. If this version of the document is not ready for publication, please explain why the document is being forwarded to the IESG.
The shepherd has gone through the document, email archive and meeting minutes. Comments have been addressed.

(4) Does the document Shepherd have any concerns about the depth or breadth of the reviews that have been performed?
None.

(5) Do portions of the document need review from a particular or from broader perspective, e.g., security, operational complexity, AAA, DNS, DHCP, XML, or internationalization? If so, describe the review that took place.
This document was discussed with security experts. This led to draft-ietf-bfd-secure-numbers.


(6) Describe any specific concerns or issues that the Document Shepherd has with this document that the Responsible Area Director and/or the IESG should be aware of? For example, perhaps he or she is uncomfortable with certain parts of the document, or has concerns whether there really is a need for it. In any event, if the WG has discussed those issues and has indicated that it still wishes to advance the document, detail those concerns here.
None

(7) Has each author confirmed that any and all appropriate IPR disclosures required for full conformance with the provisions of BCP 78 and BCP 79 have already been filed. If not, explain why?
Yes

(8) Has an IPR disclosure been filed that references this document? If so, summarize any WG discussion and conclusion regarding the IPR disclosures.
https://datatracker.ietf.org/ipr/3328/
There has been controversy on the IPR disclosure on this document for 2 main reasons:
i) IPR disclosure was late (Nov 2018)
ii) The terms of the IPR
The IPR disclosure and terms were discussed at length on the mailing list and in the WG meetings:
https://datatracker.ietf.org/meeting/104/materials/minutes-104-bfd-00.pdf
https://datatracker.ietf.org/meeting/105/materials/minutes-105-bfd-02.pdf



(9) How solid is the WG consensus behind this document? Does it represent the strong concurrence of a few individuals, with others being silent, or does the WG as a whole understand and agree with it?
Solid consensus on the technical aspects.
There is known opposition from 1 person (because of the IPR Disclosure).
https://mailarchive.ietf.org/arch/msg/rtg-bfd/u8rvWwvDWRKI3jseGHecAB9WtDo/


(10) Has anyone threatened an appeal or otherwise indicated extreme discontent? If so, please summarise the areas of conflict in separate email messages to the Responsible Area Director. (It should be in a separate email because this questionnaire is publicly available.)
None

(11) Identify any ID nits the Document Shepherd has found in this document. (See http://www.ietf.org/tools/idnits/ and the Internet-Drafts Checklist). Boilerplate checks are not enough; this check needs to be thorough.
3 warnings:
  == The copyright year in the IETF Trust and authors Copyright Line does not
    match the current year

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

  == Outdated reference: A later version (-05) exists of
    draft-ietf-bfd-secure-sequence-numbers-04

Comment about document data being 186 days in the past.

(12) Describe how the document meets any required formal review criteria, such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.
N/A

(13) Have all references within this document been identified as either normative or informative?
Yes

(14) Are there normative references to documents that are not ready for advancement or are otherwise in an unclear state? If such normative references exist, what is the plan for their completion?
None

(15) Are there downward normative references references (see RFC 3967)? If so, list these downward references to support the Area Director in the Last Call procedure.
None

(16) Will publication of this document change the status of any existing RFCs? Are those RFCs listed on the title page header, listed in the abstract, and discussed in the introduction? If the RFCs are not listed in the Abstract and Introduction, explain why, and point to the part of the document where the relationship of this document to the other RFCs is discussed. If this information is not in the document, explain why the WG considers it unnecessary.
No

(17) Describe the Document Shepherd's review of the IANA considerations section, especially with regard to its consistency with the body of the document. Confirm that all protocol extensions that the document makes are associated with the appropriate reservations in IANA registries. Confirm that any referenced IANA registries have been clearly identified. Confirm that newly created IANA registries include a detailed specification of the initial contents for the registry, that allocations procedures for future registrations are defined, and a reasonable name for the new registry has been suggested (see RFC 8126).
Assignment from the “BFD Authentication Types” registry requires Expert review. Checked https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml

(18) List any new IANA registries that require Expert Review for future allocations. Provide any public guidance that the IESG would find useful in selecting the IANA Experts for these new registries.
None

(19) Describe reviews and automated checks performed by the Document Shepherd to validate sections of the document written in a formal language, such as XML code, BNF rules, MIB definitions, YANG modules, etc.
N/A

(20) If the document contains a YANG module, has the module been checked with any of the recommended validation tools (https://trac.ietf.org/trac/ops/wiki/yang-review-tools) for syntax and formatting validation? If there are any resulting errors or warnings, what is the justification for not fixing them at this time? Does the YANG module comply with the Network Management Datastore Architecture (NMDA) as specified in RFC8342?
N/A


COMMENTS

General:
• Updates RFC5880 missing from title page
• Replace BFD frames by BFD packets or BFD control packets. Don’t use frames since RFC5880 uses packets.
• Use of term Null-authentication TLV. RFC5880 uses authentication section, doesn’t mention auth TLV.

Abstract:
Mention that this document updates RFC5880.

Requirements Language
Please put this is a separate (sub)section later, e.g. after introduction.

Introduction
First paragraph: s/is computationally intensive process/is a computationally intensive process/
Split first sentence into 2, e.g.
  Authenticating every BFD [RFC5880] packet with a Simple Password, or
  with a MD5 Message-Digest Algorithm [RFC1321], or Secure Hash
  Algorithm (SHA-1) algorithms is a computationally intensive process.
  This makes it difficult, if not impossible, to authenticate every packet,
  particularly at faster rates.

2nd paragraph: “… only BFD frames that signal a state change in BFD be authenticated.” State change is not 100% correct since P/F/D bit changes aren’t state changes (as mentioned in more detail below in section 2 comments). What about this instead: “State change, a demand mode change (to D bit) or a poll sequence change (P or F bit change) in a BFD packet are categorized as a significant BFD change. This document proposes that all BFD control packets which signal a significant BFD change MUST be authenticated if the session’s bfd.AuthType is non-zero. Other BFD control packets MAY be transmitted and received without the A bit set.” If you do use “significant BFD change”, add it to terminology section.
s/non-state change frame/BFD control packets without state or D/F/P bit change/, e.g.
“To detect a Man In the Middle (MITM) attack, it is also proposed that BFD control packets without a significant change be authenticated occasionally.  The interval of these control packets…”

Section 2
POLL and DEMAND are NOT strictly states. POLL refers to “Poll sequence” as specified in section 6.5 of RFC5880. DEMAND refers to “Demand mode” as specified in section 6.6 of RFC5880. In the table, the POLL entry refers to polling sequence enabled and in any BFD state. Likewise, the DEMAND entry refers to Demand mode. This means that a session in UP state, in demand mode and polling sequence enabled will match 3 entries in that table. It’s a bit confusing. Here’s what I suggest instead:
1. Take POLL out of the table. Add a paragraph mentioning that if P or F bit changes value, the packet MUST be authenticated
2. Take DEMAND out of the table. Add a paragraph mentioning that if D bit changes value, the packet MUST be authenticated

Another comment on the table. The text says it should be read as state change from column to row. Column INIT to row UP is n/a whereas column UP to row INIT is Auth. INIT to UP is a valid transition, UP to INIT is not (has to go through DOWN first). So I think those entries should be reversed in the table.

Last paragraph: CC frames is not defined in BFD, use “control packets” instead?

Section 3
Sequence number mentions “as defined in [RFC5880]”. Suggest mentioning bfd.XmitAuthSeq

Security Considerations.
I believe this needs to be beefed up:
1) Use of sequence number for non-authenticated frames. Secure sequence numbers even better.
2) Mention (again) that non-authenticated BFD packets which have a significant change (state, D/F/P) are dropped. So if someone injects a non-authenticated packet with Down state to take down the session, that won’t work.

Section 6.2
RFC5880 should be a normative reference.

=======================================================================================
Update December 31st 2024 on draft-ietf-bfd-optimizing-authentication-21

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

Strong consensus of a few individuals.
The initial revision of this document is from 2015. Since then there have been multiple
discussions on the BFD alias and in in-person WG meetings. The "recent" changes to the
document to use ISAAC are the ones on which the WG has been mostly silent.

There has been opposition by one person (see 2 below).

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

There has been controversy because of the IPR Disclosure.
https://mailarchive.ietf.org/arch/msg/rtg-bfd/u8rvWwvDWRKI3jseGHecAB9WtDo/

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize the areas of conflict in separate email messages to the
  responsible Area Director. (It should be in a separate email because this
  questionnaire is publicly available.)

No

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

No implementations and no known plans to implement.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

No and no.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

The document has undergone a YANG Doctor review.

7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation?

Yes.

  If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time?

No errors.

  Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

Yes.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

YANG has been validated.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

The document is clearly written and nearly ready.
There are some comments to be addressed before the document is handed off to the responsible AD:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/ca_gCMOCyXGNhhTBAvg5lGLXJK8/

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

There has been a secdir review and comments have been addressed:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/303D-DZ2DVFr9frgy75b6yyiILk/

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])?

Experimental as indicated on title page.

    Why is this the proper type
    of RFC?
Main reasons:
- No known implementations
- Not a lot of reviews on the latest revisions of the document

    Do all Datatracker state attributes correctly reflect this intent?
Yes.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]?
Yes.

    To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.
Waiting for response from 1 co-author.


13. Has each author, editor, and contributor shown their willingness to be
    listed as such?
Yes.

    If the total number of authors and editors on the front page
    is greater than five, please provide a justification.
N/A.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)
  Miscellaneous warnings:
  ----------------------------------------------------------------------------

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

    (The document does seem to have the reference to RFC 2119 which the
    ID-Checklist requires).
  -- The document date (21 October 2024) is 71 days in the past.  Is this
    intentional?

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].
No.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?
N/A

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.
No.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?
No. Note that this document should be in the same bundle as draft-ietf-bfd-secure-sequence-numbers (which is updated in "locked-step" with this document).

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.
No. This is an experimental document.

20. Describe the document shepherd's review of the IANA considerations section,
    especially with regard to its consistency with the body of the document.
    Confirm that all aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).
Section 6 matches the rest of the document and confirming the above where applicable.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.
Assignment from the “BFD Authentication Types” registry requires Expert review. Checked https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml
There is also an updated IANA YANG module in the appendix.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://wiki.ietf.org/group/ops/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://wiki.ietf.org/group/iesg/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

=======================================================================================

Update Nov 23rd 2020

All comments have been addressed.

Update July 23rd 2020

Revised comments on draft-ietf-bfd-optimizing-authentication-10

General: both "BFD control packet" and "BFD packet" are used. I think we should stick to "BFD control packet".
General: s/BFD Control packet/BFD control packet/

Introduction, next-to last paragraph. Instead of "The interval of this non-state change frame can be...", I'd suggest "The interval of these BFD packets can be..." or "The interval of the BFD packets without a significant change can be...". Anyway remove "frame" as previously discussed and avoid use of "non-state change" now that you've defined what a significant change is.

Section 1.2. The new table could be incorrectly interpreted as having 1 entry. Suggest changing this to bullet form would make it clearer.

Section 1.2 introduces the term "configured interval" but section 2 uses the term "configured period". Also for the description, what about "interval at which BFD control packets are authenticated in the UP state".
Also wondering if instead we should have a new bfd.AuthUpStateInterval state variable (see 6.8.1 of RFC5880) since having this value may not always be configured (implementation specific)?

Section 2. Replace  "frame" by "packet" or "BFD control packet"  as appropriate.

Section 2. Thanks for modifying the table as per our discussions. Regarding adding AdminDown to the table, I believe I misled you. Our discussion was based on "what happens if we're UP and receive a packet which says AdminDown"? As per 6.2 of RFC5880, the receiver would go to DOWN state. However the rows/columns in the table are for the local state (new and old), and not for state in received packet. Since we can't go to AdminDown state or leave AdmnDown state based on a packet received, AdminDown state should be removed from this table . I think it'd be good to add a reference to the BFD FSM (6.8.2 of RFC5880) in the paragraph before the table.

Section 2. For configured period (or whatever we decide to call it) add a reference to section 1.2.

Section 4. s/to to/to/

=============================================================

(1) What type of RFC is being requested (BCP, Proposed Standard, Internet Standard, Informational, Experimental, or Historic)? Why is this the proper type of RFC? Is this type of RFC indicated in the title page header?
Standards Track as indicated on title page.

(2) The IESG approval announcement includes a Document Announcement Write-Up. Please provide such a Document Announcement Write-Up. Recent examples can be found in the "Action" announcements for approved documents. The approval announcement contains the following sections:

Technical Summary:
This document describes an optimization to BFD Authentication as described in Section 6.7 of RFC5880. To remove the computational load on end-systems running BFD, it removes the requirement to authenticate all BFD control packets while providing a mechanism to keep the BFD sessions secure.

Relevant content can frequently be found in the abstract and/or introduction of the document. If not, this may be an indication that there are deficiencies in the abstract or introduction.

Working Group Summary:
Initial revision of the document is from  February 2015. Since then there have been many discussions on the mailing list and in-person at BFD WG meetings. The document has improved significantly based on the various suggestions. There is consistency on the technical content.

One action which has been postponed is updating the BFD YANG model to enable this functionality (requires a -bis of the BFD YANG document due to the new auth-type) 

There has been controversy because of the IPR Disclosure, see below.

Was there anything in WG process that is worth noting? For example, was there controversy about particular points or were there decisions where the consensus was particularly rough?

Document Quality:

Are there existing implementations of the protocol? Have a significant number of vendors indicated their plan to implement the specification? Are there any reviewers that merit special mention as having done a thorough review, e.g., one that resulted in important changes or a conclusion that the document had no substantive issues? If there was a MIB Doctor, YANG Doctor, Media Type or other expert review, what was its course (briefly)? In the case of a Media Type review, on what date was the request posted?

The document is well-written, concise and technically accurate, but requires some editorial changes before being forwarded to the IESG.


Personnel:

Who is the Document Shepherd?
Reshad Rahman, BFD co-chair.

Who is the Responsible Area Director?
Martin Vigoureux is the responsible AD.


(3) Briefly describe the review of this document that was performed by the Document Shepherd. If this version of the document is not ready for publication, please explain why the document is being forwarded to the IESG.
The shepherd has gone through the document, email archive and meeting minutes. Comments have been addressed.

(4) Does the document Shepherd have any concerns about the depth or breadth of the reviews that have been performed?
None.

(5) Do portions of the document need review from a particular or from broader perspective, e.g., security, operational complexity, AAA, DNS, DHCP, XML, or internationalization? If so, describe the review that took place.
This document was discussed with security experts. This led to draft-ietf-bfd-secure-numbers.


(6) Describe any specific concerns or issues that the Document Shepherd has with this document that the Responsible Area Director and/or the IESG should be aware of? For example, perhaps he or she is uncomfortable with certain parts of the document, or has concerns whether there really is a need for it. In any event, if the WG has discussed those issues and has indicated that it still wishes to advance the document, detail those concerns here.
None

(7) Has each author confirmed that any and all appropriate IPR disclosures required for full conformance with the provisions of BCP 78 and BCP 79 have already been filed. If not, explain why?
Yes

(8) Has an IPR disclosure been filed that references this document? If so, summarize any WG discussion and conclusion regarding the IPR disclosures.
https://datatracker.ietf.org/ipr/3328/
There has been controversy on the IPR disclosure on this document for 2 main reasons:
i) IPR disclosure was late (Nov 2018)
ii) The terms of the IPR
The IPR disclosure and terms were discussed at length on the mailing list and in the WG meetings:
https://datatracker.ietf.org/meeting/104/materials/minutes-104-bfd-00.pdf
https://datatracker.ietf.org/meeting/105/materials/minutes-105-bfd-02.pdf



(9) How solid is the WG consensus behind this document? Does it represent the strong concurrence of a few individuals, with others being silent, or does the WG as a whole understand and agree with it?
Solid consensus on the technical aspects.
There is known opposition from 1 person (because of the IPR Disclosure).
https://mailarchive.ietf.org/arch/msg/rtg-bfd/u8rvWwvDWRKI3jseGHecAB9WtDo/


(10) Has anyone threatened an appeal or otherwise indicated extreme discontent? If so, please summarise the areas of conflict in separate email messages to the Responsible Area Director. (It should be in a separate email because this questionnaire is publicly available.)
None

(11) Identify any ID nits the Document Shepherd has found in this document. (See http://www.ietf.org/tools/idnits/ and the Internet-Drafts Checklist). Boilerplate checks are not enough; this check needs to be thorough.
3 warnings:
  == The copyright year in the IETF Trust and authors Copyright Line does not
    match the current year

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

  == Outdated reference: A later version (-05) exists of
    draft-ietf-bfd-secure-sequence-numbers-04

Comment about document data being 186 days in the past.

(12) Describe how the document meets any required formal review criteria, such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.
N/A

(13) Have all references within this document been identified as either normative or informative?
Yes

(14) Are there normative references to documents that are not ready for advancement or are otherwise in an unclear state? If such normative references exist, what is the plan for their completion?
None

(15) Are there downward normative references references (see RFC 3967)? If so, list these downward references to support the Area Director in the Last Call procedure.
None

(16) Will publication of this document change the status of any existing RFCs? Are those RFCs listed on the title page header, listed in the abstract, and discussed in the introduction? If the RFCs are not listed in the Abstract and Introduction, explain why, and point to the part of the document where the relationship of this document to the other RFCs is discussed. If this information is not in the document, explain why the WG considers it unnecessary.
No

(17) Describe the Document Shepherd's review of the IANA considerations section, especially with regard to its consistency with the body of the document. Confirm that all protocol extensions that the document makes are associated with the appropriate reservations in IANA registries. Confirm that any referenced IANA registries have been clearly identified. Confirm that newly created IANA registries include a detailed specification of the initial contents for the registry, that allocations procedures for future registrations are defined, and a reasonable name for the new registry has been suggested (see RFC 8126).
Assignment from the “BFD Authentication Types” registry requires Expert review. Checked https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml

(18) List any new IANA registries that require Expert Review for future allocations. Provide any public guidance that the IESG would find useful in selecting the IANA Experts for these new registries.
None

(19) Describe reviews and automated checks performed by the Document Shepherd to validate sections of the document written in a formal language, such as XML code, BNF rules, MIB definitions, YANG modules, etc.
N/A

(20) If the document contains a YANG module, has the module been checked with any of the recommended validation tools (https://trac.ietf.org/trac/ops/wiki/yang-review-tools) for syntax and formatting validation? If there are any resulting errors or warnings, what is the justification for not fixing them at this time? Does the YANG module comply with the Network Management Datastore Architecture (NMDA) as specified in RFC8342?
N/A


COMMENTS

General:
• Updates RFC5880 missing from title page
• Replace BFD frames by BFD packets or BFD control packets. Don’t use frames since RFC5880 uses packets.
• Use of term Null-authentication TLV. RFC5880 uses authentication section, doesn’t mention auth TLV.

Abstract:
Mention that this document updates RFC5880.

Requirements Language
Please put this is a separate (sub)section later, e.g. after introduction.

Introduction
First paragraph: s/is computationally intensive process/is a computationally intensive process/
Split first sentence into 2, e.g.
  Authenticating every BFD [RFC5880] packet with a Simple Password, or
  with a MD5 Message-Digest Algorithm [RFC1321], or Secure Hash
  Algorithm (SHA-1) algorithms is a computationally intensive process.
  This makes it difficult, if not impossible, to authenticate every packet,
  particularly at faster rates.

2nd paragraph: “… only BFD frames that signal a state change in BFD be authenticated.” State change is not 100% correct since P/F/D bit changes aren’t state changes (as mentioned in more detail below in section 2 comments). What about this instead: “State change, a demand mode change (to D bit) or a poll sequence change (P or F bit change) in a BFD packet are categorized as a significant BFD change. This document proposes that all BFD control packets which signal a significant BFD change MUST be authenticated if the session’s bfd.AuthType is non-zero. Other BFD control packets MAY be transmitted and received without the A bit set.” If you do use “significant BFD change”, add it to terminology section.
s/non-state change frame/BFD control packets without state or D/F/P bit change/, e.g.
“To detect a Man In the Middle (MITM) attack, it is also proposed that BFD control packets without a significant change be authenticated occasionally.  The interval of these control packets…”

Section 2
POLL and DEMAND are NOT strictly states. POLL refers to “Poll sequence” as specified in section 6.5 of RFC5880. DEMAND refers to “Demand mode” as specified in section 6.6 of RFC5880. In the table, the POLL entry refers to polling sequence enabled and in any BFD state. Likewise, the DEMAND entry refers to Demand mode. This means that a session in UP state, in demand mode and polling sequence enabled will match 3 entries in that table. It’s a bit confusing. Here’s what I suggest instead:
1. Take POLL out of the table. Add a paragraph mentioning that if P or F bit changes value, the packet MUST be authenticated
2. Take DEMAND out of the table. Add a paragraph mentioning that if D bit changes value, the packet MUST be authenticated

Another comment on the table. The text says it should be read as state change from column to row. Column INIT to row UP is n/a whereas column UP to row INIT is Auth. INIT to UP is a valid transition, UP to INIT is not (has to go through DOWN first). So I think those entries should be reversed in the table.

Last paragraph: CC frames is not defined in BFD, use “control packets” instead?

Section 3
Sequence number mentions “as defined in [RFC5880]”. Suggest mentioning bfd.XmitAuthSeq

Security Considerations.
I believe this needs to be beefed up:
1) Use of sequence number for non-authenticated frames. Secure sequence numbers even better.
2) Mention (again) that non-authenticated BFD packets which have a significant change (state, D/F/P) are dropped. So if someone injects a non-authenticated packet with Down state to take down the session, that won’t work.

Section 6.2
RFC5880 should be a normative reference.

=======================================================================================
Update December 31st 2024 on draft-ietf-bfd-optimizing-authentication-21

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

Strong consensus of a few individuals.
The initial revision of this document is from 2015. Since then there have been multiple
discussions on the BFD alias and in in-person WG meetings. The "recent" changes to the
document to use ISAAC are the ones on which the WG has been mostly silent.

There has been opposition by one person (see 2 below).

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

There has been controversy because of the IPR Disclosure.
https://mailarchive.ietf.org/arch/msg/rtg-bfd/u8rvWwvDWRKI3jseGHecAB9WtDo/

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize the areas of conflict in separate email messages to the
  responsible Area Director. (It should be in a separate email because this
  questionnaire is publicly available.)

No

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

No implementations and no known plans to implement.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

No and no.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

The document has undergone a YANG Doctor review.

7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation?

Yes.

  If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time?

No errors.

  Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

Yes.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

YANG has been validated.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

The document is clearly written and nearly ready.
There are some comments to be addressed before the document is handed off to the responsible AD:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/ca_gCMOCyXGNhhTBAvg5lGLXJK8/

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

There has been a secdir review and comments have been addressed:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/303D-DZ2DVFr9frgy75b6yyiILk/

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])?

Experimental as indicated on title page.

    Why is this the proper type
    of RFC?
Main reasons:
- No known implementations
- Not a lot of reviews on the latest revisions of the document

    Do all Datatracker state attributes correctly reflect this intent?
Yes.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]?
Yes.

    To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.
Waiting for response from 1 co-author.


13. Has each author, editor, and contributor shown their willingness to be
    listed as such?
Yes.

    If the total number of authors and editors on the front page
    is greater than five, please provide a justification.
N/A.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)
  Miscellaneous warnings:
  ----------------------------------------------------------------------------

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

    (The document does seem to have the reference to RFC 2119 which the
    ID-Checklist requires).
  -- The document date (21 October 2024) is 71 days in the past.  Is this
    intentional?

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].
No.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?
N/A

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.
No.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?
This document should be in the same bundle as draft-ietf-bfd-secure-sequence-numbers

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.
No. This is an experimental document.

20. Describe the document shepherd's review of the IANA considerations section,
    especially with regard to its consistency with the body of the document.
    Confirm that all aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).
Section 6 matches the rest of the document and confirming the above where applicable.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.
Assignment from the “BFD Authentication Types” registry requires Expert review. Checked https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml
There is also an updated IANA YANG module in the appendix.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://wiki.ietf.org/group/ops/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://wiki.ietf.org/group/iesg/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

=======================================================================================

Update Nov 23rd 2020

All comments have been addressed.

Update July 23rd 2020

Revised comments on draft-ietf-bfd-optimizing-authentication-10

General: both "BFD control packet" and "BFD packet" are used. I think we should stick to "BFD control packet".
General: s/BFD Control packet/BFD control packet/

Introduction, next-to last paragraph. Instead of "The interval of this non-state change frame can be...", I'd suggest "The interval of these BFD packets can be..." or "The interval of the BFD packets without a significant change can be...". Anyway remove "frame" as previously discussed and avoid use of "non-state change" now that you've defined what a significant change is.

Section 1.2. The new table could be incorrectly interpreted as having 1 entry. Suggest changing this to bullet form would make it clearer.

Section 1.2 introduces the term "configured interval" but section 2 uses the term "configured period". Also for the description, what about "interval at which BFD control packets are authenticated in the UP state".
Also wondering if instead we should have a new bfd.AuthUpStateInterval state variable (see 6.8.1 of RFC5880) since having this value may not always be configured (implementation specific)?

Section 2. Replace  "frame" by "packet" or "BFD control packet"  as appropriate.

Section 2. Thanks for modifying the table as per our discussions. Regarding adding AdminDown to the table, I believe I misled you. Our discussion was based on "what happens if we're UP and receive a packet which says AdminDown"? As per 6.2 of RFC5880, the receiver would go to DOWN state. However the rows/columns in the table are for the local state (new and old), and not for state in received packet. Since we can't go to AdminDown state or leave AdmnDown state based on a packet received, AdminDown state should be removed from this table . I think it'd be good to add a reference to the BFD FSM (6.8.2 of RFC5880) in the paragraph before the table.

Section 2. For configured period (or whatever we decide to call it) add a reference to section 1.2.

Section 4. s/to to/to/

=============================================================

(1) What type of RFC is being requested (BCP, Proposed Standard, Internet Standard, Informational, Experimental, or Historic)? Why is this the proper type of RFC? Is this type of RFC indicated in the title page header?
Standards Track as indicated on title page.

(2) The IESG approval announcement includes a Document Announcement Write-Up. Please provide such a Document Announcement Write-Up. Recent examples can be found in the "Action" announcements for approved documents. The approval announcement contains the following sections:

Technical Summary:
This document describes an optimization to BFD Authentication as described in Section 6.7 of RFC5880. To remove the computational load on end-systems running BFD, it removes the requirement to authenticate all BFD control packets while providing a mechanism to keep the BFD sessions secure.

Relevant content can frequently be found in the abstract and/or introduction of the document. If not, this may be an indication that there are deficiencies in the abstract or introduction.

Working Group Summary:
Initial revision of the document is from  February 2015. Since then there have been many discussions on the mailing list and in-person at BFD WG meetings. The document has improved significantly based on the various suggestions. There is consistency on the technical content.

One action which has been postponed is updating the BFD YANG model to enable this functionality (requires a -bis of the BFD YANG document due to the new auth-type) 

There has been controversy because of the IPR Disclosure, see below.

Was there anything in WG process that is worth noting? For example, was there controversy about particular points or were there decisions where the consensus was particularly rough?

Document Quality:

Are there existing implementations of the protocol? Have a significant number of vendors indicated their plan to implement the specification? Are there any reviewers that merit special mention as having done a thorough review, e.g., one that resulted in important changes or a conclusion that the document had no substantive issues? If there was a MIB Doctor, YANG Doctor, Media Type or other expert review, what was its course (briefly)? In the case of a Media Type review, on what date was the request posted?

The document is well-written, concise and technically accurate, but requires some editorial changes before being forwarded to the IESG.


Personnel:

Who is the Document Shepherd?
Reshad Rahman, BFD co-chair.

Who is the Responsible Area Director?
Martin Vigoureux is the responsible AD.


(3) Briefly describe the review of this document that was performed by the Document Shepherd. If this version of the document is not ready for publication, please explain why the document is being forwarded to the IESG.
The shepherd has gone through the document, email archive and meeting minutes. Comments have been addressed.

(4) Does the document Shepherd have any concerns about the depth or breadth of the reviews that have been performed?
None.

(5) Do portions of the document need review from a particular or from broader perspective, e.g., security, operational complexity, AAA, DNS, DHCP, XML, or internationalization? If so, describe the review that took place.
This document was discussed with security experts. This led to draft-ietf-bfd-secure-numbers.


(6) Describe any specific concerns or issues that the Document Shepherd has with this document that the Responsible Area Director and/or the IESG should be aware of? For example, perhaps he or she is uncomfortable with certain parts of the document, or has concerns whether there really is a need for it. In any event, if the WG has discussed those issues and has indicated that it still wishes to advance the document, detail those concerns here.
None

(7) Has each author confirmed that any and all appropriate IPR disclosures required for full conformance with the provisions of BCP 78 and BCP 79 have already been filed. If not, explain why?
Yes

(8) Has an IPR disclosure been filed that references this document? If so, summarize any WG discussion and conclusion regarding the IPR disclosures.
https://datatracker.ietf.org/ipr/3328/
There has been controversy on the IPR disclosure on this document for 2 main reasons:
i) IPR disclosure was late (Nov 2018)
ii) The terms of the IPR
The IPR disclosure and terms were discussed at length on the mailing list and in the WG meetings:
https://datatracker.ietf.org/meeting/104/materials/minutes-104-bfd-00.pdf
https://datatracker.ietf.org/meeting/105/materials/minutes-105-bfd-02.pdf



(9) How solid is the WG consensus behind this document? Does it represent the strong concurrence of a few individuals, with others being silent, or does the WG as a whole understand and agree with it?
Solid consensus on the technical aspects.
There is known opposition from 1 person (because of the IPR Disclosure).
https://mailarchive.ietf.org/arch/msg/rtg-bfd/u8rvWwvDWRKI3jseGHecAB9WtDo/


(10) Has anyone threatened an appeal or otherwise indicated extreme discontent? If so, please summarise the areas of conflict in separate email messages to the Responsible Area Director. (It should be in a separate email because this questionnaire is publicly available.)
None

(11) Identify any ID nits the Document Shepherd has found in this document. (See http://www.ietf.org/tools/idnits/ and the Internet-Drafts Checklist). Boilerplate checks are not enough; this check needs to be thorough.
3 warnings:
  == The copyright year in the IETF Trust and authors Copyright Line does not
    match the current year

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

  == Outdated reference: A later version (-05) exists of
    draft-ietf-bfd-secure-sequence-numbers-04

Comment about document data being 186 days in the past.

(12) Describe how the document meets any required formal review criteria, such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.
N/A

(13) Have all references within this document been identified as either normative or informative?
Yes

(14) Are there normative references to documents that are not ready for advancement or are otherwise in an unclear state? If such normative references exist, what is the plan for their completion?
None

(15) Are there downward normative references references (see RFC 3967)? If so, list these downward references to support the Area Director in the Last Call procedure.
None

(16) Will publication of this document change the status of any existing RFCs? Are those RFCs listed on the title page header, listed in the abstract, and discussed in the introduction? If the RFCs are not listed in the Abstract and Introduction, explain why, and point to the part of the document where the relationship of this document to the other RFCs is discussed. If this information is not in the document, explain why the WG considers it unnecessary.
No

(17) Describe the Document Shepherd's review of the IANA considerations section, especially with regard to its consistency with the body of the document. Confirm that all protocol extensions that the document makes are associated with the appropriate reservations in IANA registries. Confirm that any referenced IANA registries have been clearly identified. Confirm that newly created IANA registries include a detailed specification of the initial contents for the registry, that allocations procedures for future registrations are defined, and a reasonable name for the new registry has been suggested (see RFC 8126).
Assignment from the “BFD Authentication Types” registry requires Expert review. Checked https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml

(18) List any new IANA registries that require Expert Review for future allocations. Provide any public guidance that the IESG would find useful in selecting the IANA Experts for these new registries.
None

(19) Describe reviews and automated checks performed by the Document Shepherd to validate sections of the document written in a formal language, such as XML code, BNF rules, MIB definitions, YANG modules, etc.
N/A

(20) If the document contains a YANG module, has the module been checked with any of the recommended validation tools (https://trac.ietf.org/trac/ops/wiki/yang-review-tools) for syntax and formatting validation? If there are any resulting errors or warnings, what is the justification for not fixing them at this time? Does the YANG module comply with the Network Management Datastore Architecture (NMDA) as specified in RFC8342?
N/A


COMMENTS

General:
• Updates RFC5880 missing from title page
• Replace BFD frames by BFD packets or BFD control packets. Don’t use frames since RFC5880 uses packets.
• Use of term Null-authentication TLV. RFC5880 uses authentication section, doesn’t mention auth TLV.

Abstract:
Mention that this document updates RFC5880.

Requirements Language
Please put this is a separate (sub)section later, e.g. after introduction.

Introduction
First paragraph: s/is computationally intensive process/is a computationally intensive process/
Split first sentence into 2, e.g.
  Authenticating every BFD [RFC5880] packet with a Simple Password, or
  with a MD5 Message-Digest Algorithm [RFC1321], or Secure Hash
  Algorithm (SHA-1) algorithms is a computationally intensive process.
  This makes it difficult, if not impossible, to authenticate every packet,
  particularly at faster rates.

2nd paragraph: “… only BFD frames that signal a state change in BFD be authenticated.” State change is not 100% correct since P/F/D bit changes aren’t state changes (as mentioned in more detail below in section 2 comments). What about this instead: “State change, a demand mode change (to D bit) or a poll sequence change (P or F bit change) in a BFD packet are categorized as a significant BFD change. This document proposes that all BFD control packets which signal a significant BFD change MUST be authenticated if the session’s bfd.AuthType is non-zero. Other BFD control packets MAY be transmitted and received without the A bit set.” If you do use “significant BFD change”, add it to terminology section.
s/non-state change frame/BFD control packets without state or D/F/P bit change/, e.g.
“To detect a Man In the Middle (MITM) attack, it is also proposed that BFD control packets without a significant change be authenticated occasionally.  The interval of these control packets…”

Section 2
POLL and DEMAND are NOT strictly states. POLL refers to “Poll sequence” as specified in section 6.5 of RFC5880. DEMAND refers to “Demand mode” as specified in section 6.6 of RFC5880. In the table, the POLL entry refers to polling sequence enabled and in any BFD state. Likewise, the DEMAND entry refers to Demand mode. This means that a session in UP state, in demand mode and polling sequence enabled will match 3 entries in that table. It’s a bit confusing. Here’s what I suggest instead:
1. Take POLL out of the table. Add a paragraph mentioning that if P or F bit changes value, the packet MUST be authenticated
2. Take DEMAND out of the table. Add a paragraph mentioning that if D bit changes value, the packet MUST be authenticated

Another comment on the table. The text says it should be read as state change from column to row. Column INIT to row UP is n/a whereas column UP to row INIT is Auth. INIT to UP is a valid transition, UP to INIT is not (has to go through DOWN first). So I think those entries should be reversed in the table.

Last paragraph: CC frames is not defined in BFD, use “control packets” instead?

Section 3
Sequence number mentions “as defined in [RFC5880]”. Suggest mentioning bfd.XmitAuthSeq

Security Considerations.
I believe this needs to be beefed up:
1) Use of sequence number for non-authenticated frames. Secure sequence numbers even better.
2) Mention (again) that non-authenticated BFD packets which have a significant change (state, D/F/P) are dropped. So if someone injects a non-authenticated packet with Down state to take down the session, that won’t work.

Section 6.2
RFC5880 should be a normative reference.

=======================================================================================
Update December 31st 2024 on draft-ietf-bfd-optimizing-authentication-21

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

Strong consensus of a few individuals.
The initial revision of this document is from 2015. Since then there have been multiple
discussions on the BFD alias and in in-person WG meetings. The "recent" changes to the
document to use ISAAC are the ones on which the WG has been mostly silent.

There has been opposition by one person (see 2 below).

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

There has been controversy because of the IPR Disclosure.
https://mailarchive.ietf.org/arch/msg/rtg-bfd/u8rvWwvDWRKI3jseGHecAB9WtDo/

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize the areas of conflict in separate email messages to the
  responsible Area Director. (It should be in a separate email because this
  questionnaire is publicly available.)

No

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

No implementations and no known plans to implement.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

No and no.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

The document has undergone a YANG Doctor review.

7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation?

Yes.

  If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time?

No errors.

  Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

Yes.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

YANG has been validated.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

The document is clearly written and nearly ready.
There are some comments to be addressed before the document is handed off to the responsible AD.

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

There has been a secdir review and comments have been addressed:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/303D-DZ2DVFr9frgy75b6yyiILk/

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])?

Experimental as indicated on title page.

    Why is this the proper type
    of RFC?
Main reasons:
- No known implementations
- Not a lot of reviews on the latest revisions of the document

    Do all Datatracker state attributes correctly reflect this intent?
Yes.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]?
Yes.

    To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.
Waiting for response from 1 co-author.


13. Has each author, editor, and contributor shown their willingness to be
    listed as such?
Yes.

    If the total number of authors and editors on the front page
    is greater than five, please provide a justification.
N/A.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)
  Miscellaneous warnings:
  ----------------------------------------------------------------------------

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

    (The document does seem to have the reference to RFC 2119 which the
    ID-Checklist requires).
  -- The document date (21 October 2024) is 71 days in the past.  Is this
    intentional?

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].
No.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?
N/A

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.
No.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?
This document should be in the same bundle as draft-ietf-bfd-secure-sequence-numbers

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.
No. This is an experimental document.

20. Describe the document shepherd's review of the IANA considerations section,
    especially with regard to its consistency with the body of the document.
    Confirm that all aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).
Section 6 matches the rest of the document and confirming the above where applicable.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.
Assignment from the “BFD Authentication Types” registry requires Expert review. Checked https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml
There is also an updated IANA YANG module in the appendix.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://wiki.ietf.org/group/ops/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://wiki.ietf.org/group/iesg/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

=======================================================================================

Update Nov 23rd 2020

All comments have been addressed.

Update July 23rd 2020

Revised comments on draft-ietf-bfd-optimizing-authentication-10

General: both "BFD control packet" and "BFD packet" are used. I think we should stick to "BFD control packet".
General: s/BFD Control packet/BFD control packet/

Introduction, next-to last paragraph. Instead of "The interval of this non-state change frame can be...", I'd suggest "The interval of these BFD packets can be..." or "The interval of the BFD packets without a significant change can be...". Anyway remove "frame" as previously discussed and avoid use of "non-state change" now that you've defined what a significant change is.

Section 1.2. The new table could be incorrectly interpreted as having 1 entry. Suggest changing this to bullet form would make it clearer.

Section 1.2 introduces the term "configured interval" but section 2 uses the term "configured period". Also for the description, what about "interval at which BFD control packets are authenticated in the UP state".
Also wondering if instead we should have a new bfd.AuthUpStateInterval state variable (see 6.8.1 of RFC5880) since having this value may not always be configured (implementation specific)?

Section 2. Replace  "frame" by "packet" or "BFD control packet"  as appropriate.

Section 2. Thanks for modifying the table as per our discussions. Regarding adding AdminDown to the table, I believe I misled you. Our discussion was based on "what happens if we're UP and receive a packet which says AdminDown"? As per 6.2 of RFC5880, the receiver would go to DOWN state. However the rows/columns in the table are for the local state (new and old), and not for state in received packet. Since we can't go to AdminDown state or leave AdmnDown state based on a packet received, AdminDown state should be removed from this table . I think it'd be good to add a reference to the BFD FSM (6.8.2 of RFC5880) in the paragraph before the table.

Section 2. For configured period (or whatever we decide to call it) add a reference to section 1.2.

Section 4. s/to to/to/

=============================================================

(1) What type of RFC is being requested (BCP, Proposed Standard, Internet Standard, Informational, Experimental, or Historic)? Why is this the proper type of RFC? Is this type of RFC indicated in the title page header?
Standards Track as indicated on title page.

(2) The IESG approval announcement includes a Document Announcement Write-Up. Please provide such a Document Announcement Write-Up. Recent examples can be found in the "Action" announcements for approved documents. The approval announcement contains the following sections:

Technical Summary:
This document describes an optimization to BFD Authentication as described in Section 6.7 of RFC5880. To remove the computational load on end-systems running BFD, it removes the requirement to authenticate all BFD control packets while providing a mechanism to keep the BFD sessions secure.

Relevant content can frequently be found in the abstract and/or introduction of the document. If not, this may be an indication that there are deficiencies in the abstract or introduction.

Working Group Summary:
Initial revision of the document is from  February 2015. Since then there have been many discussions on the mailing list and in-person at BFD WG meetings. The document has improved significantly based on the various suggestions. There is consistency on the technical content.

One action which has been postponed is updating the BFD YANG model to enable this functionality (requires a -bis of the BFD YANG document due to the new auth-type) 

There has been controversy because of the IPR Disclosure, see below.

Was there anything in WG process that is worth noting? For example, was there controversy about particular points or were there decisions where the consensus was particularly rough?

Document Quality:

Are there existing implementations of the protocol? Have a significant number of vendors indicated their plan to implement the specification? Are there any reviewers that merit special mention as having done a thorough review, e.g., one that resulted in important changes or a conclusion that the document had no substantive issues? If there was a MIB Doctor, YANG Doctor, Media Type or other expert review, what was its course (briefly)? In the case of a Media Type review, on what date was the request posted?

The document is well-written, concise and technically accurate, but requires some editorial changes before being forwarded to the IESG.


Personnel:

Who is the Document Shepherd?
Reshad Rahman, BFD co-chair.

Who is the Responsible Area Director?
Martin Vigoureux is the responsible AD.


(3) Briefly describe the review of this document that was performed by the Document Shepherd. If this version of the document is not ready for publication, please explain why the document is being forwarded to the IESG.
The shepherd has gone through the document, email archive and meeting minutes. Comments have been addressed.

(4) Does the document Shepherd have any concerns about the depth or breadth of the reviews that have been performed?
None.

(5) Do portions of the document need review from a particular or from broader perspective, e.g., security, operational complexity, AAA, DNS, DHCP, XML, or internationalization? If so, describe the review that took place.
This document was discussed with security experts. This led to draft-ietf-bfd-secure-numbers.


(6) Describe any specific concerns or issues that the Document Shepherd has with this document that the Responsible Area Director and/or the IESG should be aware of? For example, perhaps he or she is uncomfortable with certain parts of the document, or has concerns whether there really is a need for it. In any event, if the WG has discussed those issues and has indicated that it still wishes to advance the document, detail those concerns here.
None

(7) Has each author confirmed that any and all appropriate IPR disclosures required for full conformance with the provisions of BCP 78 and BCP 79 have already been filed. If not, explain why?
Yes

(8) Has an IPR disclosure been filed that references this document? If so, summarize any WG discussion and conclusion regarding the IPR disclosures.
https://datatracker.ietf.org/ipr/3328/
There has been controversy on the IPR disclosure on this document for 2 main reasons:
i) IPR disclosure was late (Nov 2018)
ii) The terms of the IPR
The IPR disclosure and terms were discussed at length on the mailing list and in the WG meetings:
https://datatracker.ietf.org/meeting/104/materials/minutes-104-bfd-00.pdf
https://datatracker.ietf.org/meeting/105/materials/minutes-105-bfd-02.pdf



(9) How solid is the WG consensus behind this document? Does it represent the strong concurrence of a few individuals, with others being silent, or does the WG as a whole understand and agree with it?
Solid consensus on the technical aspects.
There is known opposition from 1 person (because of the IPR Disclosure).
https://mailarchive.ietf.org/arch/msg/rtg-bfd/u8rvWwvDWRKI3jseGHecAB9WtDo/


(10) Has anyone threatened an appeal or otherwise indicated extreme discontent? If so, please summarise the areas of conflict in separate email messages to the Responsible Area Director. (It should be in a separate email because this questionnaire is publicly available.)
None

(11) Identify any ID nits the Document Shepherd has found in this document. (See http://www.ietf.org/tools/idnits/ and the Internet-Drafts Checklist). Boilerplate checks are not enough; this check needs to be thorough.
3 warnings:
  == The copyright year in the IETF Trust and authors Copyright Line does not
    match the current year

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

  == Outdated reference: A later version (-05) exists of
    draft-ietf-bfd-secure-sequence-numbers-04

Comment about document data being 186 days in the past.

(12) Describe how the document meets any required formal review criteria, such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.
N/A

(13) Have all references within this document been identified as either normative or informative?
Yes

(14) Are there normative references to documents that are not ready for advancement or are otherwise in an unclear state? If such normative references exist, what is the plan for their completion?
None

(15) Are there downward normative references references (see RFC 3967)? If so, list these downward references to support the Area Director in the Last Call procedure.
None

(16) Will publication of this document change the status of any existing RFCs? Are those RFCs listed on the title page header, listed in the abstract, and discussed in the introduction? If the RFCs are not listed in the Abstract and Introduction, explain why, and point to the part of the document where the relationship of this document to the other RFCs is discussed. If this information is not in the document, explain why the WG considers it unnecessary.
No

(17) Describe the Document Shepherd's review of the IANA considerations section, especially with regard to its consistency with the body of the document. Confirm that all protocol extensions that the document makes are associated with the appropriate reservations in IANA registries. Confirm that any referenced IANA registries have been clearly identified. Confirm that newly created IANA registries include a detailed specification of the initial contents for the registry, that allocations procedures for future registrations are defined, and a reasonable name for the new registry has been suggested (see RFC 8126).
Assignment from the “BFD Authentication Types” registry requires Expert review. Checked https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml

(18) List any new IANA registries that require Expert Review for future allocations. Provide any public guidance that the IESG would find useful in selecting the IANA Experts for these new registries.
None

(19) Describe reviews and automated checks performed by the Document Shepherd to validate sections of the document written in a formal language, such as XML code, BNF rules, MIB definitions, YANG modules, etc.
N/A

(20) If the document contains a YANG module, has the module been checked with any of the recommended validation tools (https://trac.ietf.org/trac/ops/wiki/yang-review-tools) for syntax and formatting validation? If there are any resulting errors or warnings, what is the justification for not fixing them at this time? Does the YANG module comply with the Network Management Datastore Architecture (NMDA) as specified in RFC8342?
N/A


COMMENTS

General:
• Updates RFC5880 missing from title page
• Replace BFD frames by BFD packets or BFD control packets. Don’t use frames since RFC5880 uses packets.
• Use of term Null-authentication TLV. RFC5880 uses authentication section, doesn’t mention auth TLV.

Abstract:
Mention that this document updates RFC5880.

Requirements Language
Please put this is a separate (sub)section later, e.g. after introduction.

Introduction
First paragraph: s/is computationally intensive process/is a computationally intensive process/
Split first sentence into 2, e.g.
  Authenticating every BFD [RFC5880] packet with a Simple Password, or
  with a MD5 Message-Digest Algorithm [RFC1321], or Secure Hash
  Algorithm (SHA-1) algorithms is a computationally intensive process.
  This makes it difficult, if not impossible, to authenticate every packet,
  particularly at faster rates.

2nd paragraph: “… only BFD frames that signal a state change in BFD be authenticated.” State change is not 100% correct since P/F/D bit changes aren’t state changes (as mentioned in more detail below in section 2 comments). What about this instead: “State change, a demand mode change (to D bit) or a poll sequence change (P or F bit change) in a BFD packet are categorized as a significant BFD change. This document proposes that all BFD control packets which signal a significant BFD change MUST be authenticated if the session’s bfd.AuthType is non-zero. Other BFD control packets MAY be transmitted and received without the A bit set.” If you do use “significant BFD change”, add it to terminology section.
s/non-state change frame/BFD control packets without state or D/F/P bit change/, e.g.
“To detect a Man In the Middle (MITM) attack, it is also proposed that BFD control packets without a significant change be authenticated occasionally.  The interval of these control packets…”

Section 2
POLL and DEMAND are NOT strictly states. POLL refers to “Poll sequence” as specified in section 6.5 of RFC5880. DEMAND refers to “Demand mode” as specified in section 6.6 of RFC5880. In the table, the POLL entry refers to polling sequence enabled and in any BFD state. Likewise, the DEMAND entry refers to Demand mode. This means that a session in UP state, in demand mode and polling sequence enabled will match 3 entries in that table. It’s a bit confusing. Here’s what I suggest instead:
1. Take POLL out of the table. Add a paragraph mentioning that if P or F bit changes value, the packet MUST be authenticated
2. Take DEMAND out of the table. Add a paragraph mentioning that if D bit changes value, the packet MUST be authenticated

Another comment on the table. The text says it should be read as state change from column to row. Column INIT to row UP is n/a whereas column UP to row INIT is Auth. INIT to UP is a valid transition, UP to INIT is not (has to go through DOWN first). So I think those entries should be reversed in the table.

Last paragraph: CC frames is not defined in BFD, use “control packets” instead?

Section 3
Sequence number mentions “as defined in [RFC5880]”. Suggest mentioning bfd.XmitAuthSeq

Security Considerations.
I believe this needs to be beefed up:
1) Use of sequence number for non-authenticated frames. Secure sequence numbers even better.
2) Mention (again) that non-authenticated BFD packets which have a significant change (state, D/F/P) are dropped. So if someone injects a non-authenticated packet with Down state to take down the session, that won’t work.

Section 6.2
RFC5880 should be a normative reference.

=======================================================================================
Update December 31st 2024 on draft-ietf-bfd-optimizing-authentication-21

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

Strong consensus of a few individuals.
The initial revision of this document is from 2015. Since then there have been multiple
discussions on the BFD alias and in in-person WG meetings. The "recent" changes to the
document to use ISAAC are the ones on which the WG has been mostly silent.

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

There has been controversy because of the IPR Disclosure, see below.

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize the areas of conflict in separate email messages to the
  responsible Area Director. (It should be in a separate email because this
  questionnaire is publicly available.)

No

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

No implementations and no known plans to implement.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

No and no.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

The document has undergone a YANG Doctor review.

7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation?

Yes.

  If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time?

No errors.

  Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

Yes.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

YANG has been validated.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

The document is clearly written and nearly ready.
There are some comments to be addressed before the document is handed off to the responsible AD.

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

There has been a secdir review and comments have been addressed:
https://mailarchive.ietf.org/arch/msg/rtg-bfd/303D-DZ2DVFr9frgy75b6yyiILk/

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])?

Experimental as indicated on title page.

    Why is this the proper type
    of RFC?
Main reasons:
- No known implementations
- Not a lot of reviews on the latest revisions of the document

    Do all Datatracker state attributes correctly reflect this intent?
Yes.

12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]?
Yes.

    To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.
Waiting for response from 1 co-author.


13. Has each author, editor, and contributor shown their willingness to be
    listed as such?
Yes.

    If the total number of authors and editors on the front page
    is greater than five, please provide a justification.
N/A.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)
  Miscellaneous warnings:
  ----------------------------------------------------------------------------

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

    (The document does seem to have the reference to RFC 2119 which the
    ID-Checklist requires).
  -- The document date (21 October 2024) is 71 days in the past.  Is this
    intentional?

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].
No.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?
N/A

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.
No.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?
This document should be in the same bundle as draft-ietf-bfd-secure-sequence-numbers

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.
No. This is an experimental document.

20. Describe the document shepherd's review of the IANA considerations section,
    especially with regard to its consistency with the body of the document.
    Confirm that all aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).
Section 6 matches the rest of the document and confirming the above where applicable.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.
Assignment from the “BFD Authentication Types” registry requires Expert review. Checked https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml
There is also an updated IANA YANG module in the appendix.

[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://wiki.ietf.org/group/ops/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://wiki.ietf.org/group/iesg/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]: https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/

=======================================================================================

Update Nov 23rd 2020

All comments have been addressed.

Update July 23rd 2020

Revised comments on draft-ietf-bfd-optimizing-authentication-10

General: both "BFD control packet" and "BFD packet" are used. I think we should stick to "BFD control packet".
General: s/BFD Control packet/BFD control packet/

Introduction, next-to last paragraph. Instead of "The interval of this non-state change frame can be...", I'd suggest "The interval of these BFD packets can be..." or "The interval of the BFD packets without a significant change can be...". Anyway remove "frame" as previously discussed and avoid use of "non-state change" now that you've defined what a significant change is.

Section 1.2. The new table could be incorrectly interpreted as having 1 entry. Suggest changing this to bullet form would make it clearer.

Section 1.2 introduces the term "configured interval" but section 2 uses the term "configured period". Also for the description, what about "interval at which BFD control packets are authenticated in the UP state".
Also wondering if instead we should have a new bfd.AuthUpStateInterval state variable (see 6.8.1 of RFC5880) since having this value may not always be configured (implementation specific)?

Section 2. Replace  "frame" by "packet" or "BFD control packet"  as appropriate.

Section 2. Thanks for modifying the table as per our discussions. Regarding adding AdminDown to the table, I believe I misled you. Our discussion was based on "what happens if we're UP and receive a packet which says AdminDown"? As per 6.2 of RFC5880, the receiver would go to DOWN state. However the rows/columns in the table are for the local state (new and old), and not for state in received packet. Since we can't go to AdminDown state or leave AdmnDown state based on a packet received, AdminDown state should be removed from this table . I think it'd be good to add a reference to the BFD FSM (6.8.2 of RFC5880) in the paragraph before the table.

Section 2. For configured period (or whatever we decide to call it) add a reference to section 1.2.

Section 4. s/to to/to/

=============================================================

(1) What type of RFC is being requested (BCP, Proposed Standard, Internet Standard, Informational, Experimental, or Historic)? Why is this the proper type of RFC? Is this type of RFC indicated in the title page header?
Standards Track as indicated on title page.

(2) The IESG approval announcement includes a Document Announcement Write-Up. Please provide such a Document Announcement Write-Up. Recent examples can be found in the "Action" announcements for approved documents. The approval announcement contains the following sections:

Technical Summary:
This document describes an optimization to BFD Authentication as described in Section 6.7 of RFC5880. To remove the computational load on end-systems running BFD, it removes the requirement to authenticate all BFD control packets while providing a mechanism to keep the BFD sessions secure.

Relevant content can frequently be found in the abstract and/or introduction of the document. If not, this may be an indication that there are deficiencies in the abstract or introduction.

Working Group Summary:
Initial revision of the document is from  February 2015. Since then there have been many discussions on the mailing list and in-person at BFD WG meetings. The document has improved significantly based on the various suggestions. There is consistency on the technical content.

One action which has been postponed is updating the BFD YANG model to enable this functionality (requires a -bis of the BFD YANG document due to the new auth-type) 

There has been controversy because of the IPR Disclosure, see below.

Was there anything in WG process that is worth noting? For example, was there controversy about particular points or were there decisions where the consensus was particularly rough?

Document Quality:

Are there existing implementations of the protocol? Have a significant number of vendors indicated their plan to implement the specification? Are there any reviewers that merit special mention as having done a thorough review, e.g., one that resulted in important changes or a conclusion that the document had no substantive issues? If there was a MIB Doctor, YANG Doctor, Media Type or other expert review, what was its course (briefly)? In the case of a Media Type review, on what date was the request posted?

The document is well-written, concise and technically accurate, but requires some editorial changes before being forwarded to the IESG.


Personnel:

Who is the Document Shepherd?
Reshad Rahman, BFD co-chair.

Who is the Responsible Area Director?
Martin Vigoureux is the responsible AD.


(3) Briefly describe the review of this document that was performed by the Document Shepherd. If this version of the document is not ready for publication, please explain why the document is being forwarded to the IESG.
The shepherd has gone through the document, email archive and meeting minutes. Comments have been addressed.

(4) Does the document Shepherd have any concerns about the depth or breadth of the reviews that have been performed?
None.

(5) Do portions of the document need review from a particular or from broader perspective, e.g., security, operational complexity, AAA, DNS, DHCP, XML, or internationalization? If so, describe the review that took place.
This document was discussed with security experts. This led to draft-ietf-bfd-secure-numbers.


(6) Describe any specific concerns or issues that the Document Shepherd has with this document that the Responsible Area Director and/or the IESG should be aware of? For example, perhaps he or she is uncomfortable with certain parts of the document, or has concerns whether there really is a need for it. In any event, if the WG has discussed those issues and has indicated that it still wishes to advance the document, detail those concerns here.
None

(7) Has each author confirmed that any and all appropriate IPR disclosures required for full conformance with the provisions of BCP 78 and BCP 79 have already been filed. If not, explain why?
Yes

(8) Has an IPR disclosure been filed that references this document? If so, summarize any WG discussion and conclusion regarding the IPR disclosures.
https://datatracker.ietf.org/ipr/3328/
There has been controversy on the IPR disclosure on this document for 2 main reasons:
i) IPR disclosure was late (Nov 2018)
ii) The terms of the IPR
The IPR disclosure and terms were discussed at length on the mailing list and in the WG meetings:
https://datatracker.ietf.org/meeting/104/materials/minutes-104-bfd-00.pdf
https://datatracker.ietf.org/meeting/105/materials/minutes-105-bfd-02.pdf



(9) How solid is the WG consensus behind this document? Does it represent the strong concurrence of a few individuals, with others being silent, or does the WG as a whole understand and agree with it?
Solid consensus on the technical aspects.
There is known opposition from 1 person (because of the IPR Disclosure).
https://mailarchive.ietf.org/arch/msg/rtg-bfd/u8rvWwvDWRKI3jseGHecAB9WtDo/


(10) Has anyone threatened an appeal or otherwise indicated extreme discontent? If so, please summarise the areas of conflict in separate email messages to the Responsible Area Director. (It should be in a separate email because this questionnaire is publicly available.)
None

(11) Identify any ID nits the Document Shepherd has found in this document. (See http://www.ietf.org/tools/idnits/ and the Internet-Drafts Checklist). Boilerplate checks are not enough; this check needs to be thorough.
3 warnings:
  == The copyright year in the IETF Trust and authors Copyright Line does not
    match the current year

  == The document seems to lack the recommended RFC 2119 boilerplate, even if
    it appears to use RFC 2119 keywords -- however, there's a paragraph with
    a matching beginning. Boilerplate error?

  == Outdated reference: A later version (-05) exists of
    draft-ietf-bfd-secure-sequence-numbers-04

Comment about document data being 186 days in the past.

(12) Describe how the document meets any required formal review criteria, such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.
N/A

(13) Have all references within this document been identified as either normative or informative?
Yes

(14) Are there normative references to documents that are not ready for advancement or are otherwise in an unclear state? If such normative references exist, what is the plan for their completion?
None

(15) Are there downward normative references references (see RFC 3967)? If so, list these downward references to support the Area Director in the Last Call procedure.
None

(16) Will publication of this document change the status of any existing RFCs? Are those RFCs listed on the title page header, listed in the abstract, and discussed in the introduction? If the RFCs are not listed in the Abstract and Introduction, explain why, and point to the part of the document where the relationship of this document to the other RFCs is discussed. If this information is not in the document, explain why the WG considers it unnecessary.
No

(17) Describe the Document Shepherd's review of the IANA considerations section, especially with regard to its consistency with the body of the document. Confirm that all protocol extensions that the document makes are associated with the appropriate reservations in IANA registries. Confirm that any referenced IANA registries have been clearly identified. Confirm that newly created IANA registries include a detailed specification of the initial contents for the registry, that allocations procedures for future registrations are defined, and a reasonable name for the new registry has been suggested (see RFC 8126).
Assignment from the “BFD Authentication Types” registry requires Expert review. Checked https://www.iana.org/assignments/bfd-parameters/bfd-parameters.xhtml

(18) List any new IANA registries that require Expert Review for future allocations. Provide any public guidance that the IESG would find useful in selecting the IANA Experts for these new registries.
None

(19) Describe reviews and automated checks performed by the Document Shepherd to validate sections of the document written in a formal language, such as XML code, BNF rules, MIB definitions, YANG modules, etc.
N/A

(20) If the document contains a YANG module, has the module been checked with any of the recommended validation tools (https://trac.ietf.org/trac/ops/wiki/yang-review-tools) for syntax and formatting validation? If there are any resulting errors or warnings, what is the justification for not fixing them at this time? Does the YANG module comply with the Network Management Datastore Architecture (NMDA) as specified in RFC8342?
N/A


COMMENTS

General:
• Updates RFC5880 missing from title page
• Replace BFD frames by BFD packets or BFD control packets. Don’t use frames since RFC5880 uses packets.
• Use of term Null-authentication TLV. RFC5880 uses authentication section, doesn’t mention auth TLV.

Abstract:
Mention that this document updates RFC5880.

Requirements Language
Please put this is a separate (sub)section later, e.g. after introduction.

Introduction
First paragraph: s/is computationally intensive process/is a computationally intensive process/
Split first sentence into 2, e.g.
  Authenticating every BFD [RFC5880] packet with a Simple Password, or
  with a MD5 Message-Digest Algorithm [RFC1321], or Secure Hash
  Algorithm (SHA-1) algorithms is a computationally intensive process.
  This makes it difficult, if not impossible, to authenticate every packet,
  particularly at faster rates.

2nd paragraph: “… only BFD frames that signal a state change in BFD be authenticated.” State change is not 100% correct since P/F/D bit changes aren’t state changes (as mentioned in more detail below in section 2 comments). What about this instead: “State change, a demand mode change (to D bit) or a poll sequence change (P or F bit change) in a BFD packet are categorized as a significant BFD change. This document proposes that all BFD control packets which signal a significant BFD change MUST be authenticated if the session’s bfd.AuthType is non-zero. Other BFD control packets MAY be transmitted and received without the A bit set.” If you do use “significant BFD change”, add it to terminology section.
s/non-state change frame/BFD control packets without state or D/F/P bit change/, e.g.
“To detect a Man In the Middle (MITM) attack, it is also proposed that BFD control packets without a significant change be authenticated occasionally.  The interval of these control packets…”

Section 2
POLL and DEMAND are NOT strictly states. POLL refers to “Poll sequence” as specified in section 6.5 of RFC5880. DEMAND refers to “Demand mode” as specified in section 6.6 of RFC5880. In the table, the POLL entry refers to polling sequence enabled and in any BFD state. Likewise, the DEMAND entry refers to Demand mode. This means that a session in UP state, in demand mode and polling sequence enabled will match 3 entries in that table. It’s a bit confusing. Here’s what I suggest instead:
1. Take POLL out of the table. Add a paragraph mentioning that if P or F bit changes value, the packet MUST be authenticated
2. Take DEMAND out of the table. Add a paragraph mentioning that if D bit changes value, the packet MUST be authenticated

Another comment on the table. The text says it should be read as state change from column to row. Column INIT to row UP is n/a whereas column UP to row INIT is Auth. INIT to UP is a valid transition, UP to INIT is not (has to go through DOWN first). So I think those entries should be reversed in the table.

Last paragraph: CC frames is not defined in BFD, use “control packets” instead?

Section 3
Sequence number mentions “as defined in [RFC5880]”. Suggest mentioning bfd.XmitAuthSeq

Security Considerations.
I believe this needs to be beefed up:
1) Use of sequence number for non-authenticated frames. Secure sequence numbers even better.
2) Mention (again) that non-authenticated BFD packets which have a significant change (state, D/F/P) are dropped. So if someone injects a non-authenticated packet with Down state to take down the session, that won’t work.

Section 6.2
RFC5880 should be a normative reference.