RFC 9827
Renaming the Extended Sequence Numbers (ESN) Transform Type in the Internet Key Exchange Protocol Version 2 (IKEv2), November 2025
- File formats:

- Also available: XML file for editing
- Status:
- PROPOSED STANDARD
- Updates:
- RFC 7296
- Author:
- V. Smyslov
- Stream:
- IETF
- Source:
- ipsecme (sec)
Cite this RFC: TXT | XML | BibTeX
DOI: https://doi.org/10.17487/RFC9827
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Abstract
This document clarifies and extends the meaning of Transform Type 5 in Internet Key Exchange Protocol Version 2 (IKEv2). It updates RFC 7296 by renaming Transform Type 5 from "Extended Sequence Numbers (ESN)" to "Sequence Numbers (SN)". It also renames two currently defined values for this Transform Type: value 0 from "No Extended Sequence Numbers" to "32-bit Sequential Numbers" and value 1 from "Extended Sequence Numbers" to "Partially Transmitted 64-bit Sequential Numbers".
For the definition of Status, see RFC 2026.
For the definition of Stream, see RFC 8729.