RFC 5586, "MPLS Generic Associated Channel", June 2009Source of RFC: mpls (rtg)
Errata ID: 4364
Reported By: Alexander ("Sasha") Vainshtein
Date Reported: 2015-05-12
Rejected by: Deborah Brungard
Date Rejected: 2015-05-18
Section 4.2.1 says:
The Time-To-Live (TTL) field of the LSE that contains the GAL follows the definition and processing rules specified in [RFC3443].
It should say:
The value of the Time-To-Live (TTL) field of the LSE that contains the GAL follows is irrelevant as long as it exceeds 1. (Setting this value to 0 or 1 SHOULD be avoided because it could result in trapping the OAM packets in with wrong reason: "TTL expiration" instead of "GAL encountered").
The processing rules specific in RFC 3443 deal with handling TTL in the LSE of a labeled packets that are forwarded based on this LSE, or with setting the TTL value by a LER pushing a label stack on an unlabeled packet.
As per the last para in Section 4.2, LSRs and LERs MUST NOT forward packets based on the LSE that contains GAL, hence these rules are mainly not applicable.
This proposes a change to the RFC which needs to be agreed via working group consensus.