RFC 5884, "Bidirectional Forwarding Detection (BFD) for MPLS Label Switched Paths (LSPs)", June 2010Source of RFC: bfd (rtg)
Errata ID: 5085
Reported By: Balaji Rajagopalan
Date Reported: 2017-08-11
Section 6 says:
The egress LSR MAY respond with an LSP Ping Echo reply message that carries the local discriminator assigned by it for the BFD session.
It should say:
The egress LSR MUST respond with an LSP Ping Echo reply message that MAY carry the local discriminator assigned by it for the BFD session.
It is not clear from the original text which of the following is optional:
- The egress MUST send a reply, but the discriminator in the reply is optional
- The reply itself is optional
Technically, the reply cannot be optional, because the egress needs to report LSP-Ping verification status to the ingress.
The proposed text recommends to include BFD discriminator in the reply. This was the intent of the original text.