RFC 8287 defines the extensions to perform LSP Ping and Traceroute for Segment Routing IGPPrefix and IGP-Adjacency Segment Identifiers (SIDs) with the MPLS data plane. RFC 8287 proposes three Target Forwarding Equivalence Class (FEC) Stack sub-TLVs. While RFC 8287 defines the format and procedure to handle those sub-TLVs, it does not sufficiently clarify how the length of the Segment ID sub-TLVs should be computed to be included in the Length field of the sub-TLVs. This ambiguity has resulted in interoperability issues.
This document updates RFC 8287 by clarifying the length of each of the Segment ID sub-TLVs defined in RFC 8287.