RFC Errata
RFC 5549, "Advertising IPv4 Network Layer Reachability Information with an IPv6 Next Hop", May 2009
Note: This RFC has been obsoleted by RFC 8950
Source of RFC: softwire (int)
Errata ID: 6786
Status: Rejected
Type: Technical
Publication Format(s) : TEXT
Reported By: Mike Dubrovsky
Date Reported: 2021-12-17
Rejected by: Éric Vyncke
Date Rejected: 2023-08-02
Section 4 says:
A BGP speaker MUST only advertise to a BGP peer the IPv4 or VPN-IPv4 NLRI with an IPv6 Next Hop if the BGP speaker has first ascertained via BGP Capability Advertisement that the BGP peer supports the Extended Next Hop Encoding capability for the relevant AFI/SAFI pair.
It should say:
A BGP speaker MUST only advertise to a BGP peer the IPv4 or VPN-IPv4 NLRI with an IPv6 Next Hop if the BGP speaker has first ascertained via BGP Capability Advertisement that the BGP peer supports the Extended Next Hop Encoding capability for the relevant AFI/SAFI pair. IPv4 or VPN-IPv4 NLRI with an IPv6 Next Hop SHOULD be treated as malformed if it received from a BGP speaker that has not sent BGP Capability Advertisement for the relevant AFI/SAFI pair.
Notes:
The behavior was not explicitly mentioned.
--VERIFIER NOTES--
The RFC 5549 has been obsoleted by RFC 8950. Per point 7 of https://www.ietf.org/about/groups/iesg/statements/processing-errata-ietf-stream/, this errata is rejected.
It appears to me that RFC 8950 may have the same error and may also require a similar errata.
Thanks for the report.