rfc-9214

OSPFv3 Code Point for MPLS LSP Ping

N. Nainar, C. Pignataro, M. Aissaoui

date2022-04 streamIETF areartg wgmpls statusPROPOSED STANDARD pages6 canonicalhttps://www.rfc-editor.org/rfc/rfc9214 doi10.17487/RFC9214

IANA has created "Protocol in the Segment ID Sub-TLV" and "Protocol in Label Stack Sub-TLV of Downstream Detailed Mapping TLV" registries under the "Multiprotocol Label Switching (MPLS) Label Switched Paths (LSPs) Ping Parameters" registry. RFC 8287 defines the code points for Open Shortest Path First (OSPF) and Intermediate System to Intermediate System (IS-IS) protocols. This document specifies the code point to be used in the Segment ID sub-TLV and Downstream Detailed Mapping (DDMAP) TLV when the Interior Gateway Protocol (IGP) is OSPFv3. This document also updates RFC 8287 by clarifying that the existing "OSPF" code point is to be used only to indicate OSPFv2 and by defining the behavior when the Segment ID sub-TLV indicates the use of IPv6.

updates

rfc-8287 — Label Switched Path (LSP) Ping/Traceroute for Segment Routing (SR) IGP-Prefix and IGP-Adjacency Segment Identifiers (SIDs) with MPLS Data Planes

Extracted elements (11)

design-rationale §1

A separate OSPFv3 code point (value 3) is introduced rather than reusing the existing OSPF code point (value 1) because OSPFv2 is not compatible with IPv6 addresses used by Segment ID sub-TLV Types 35 and 36, necessitating clear IGP version disambiguation.

mpls, routing

interoperability-note §4

Responders receiving Segment ID sub-TLV Types 35 or 36 with protocol value 1 (OSPF) MAY treat it as 'Any IGP Protocol' (value 0) to maintain compatibility with legacy implementations that incorrectly used value 1 to indicate OSPFv3.

mpls, routing

normative-requirement §4 MUST NOT

The initiator MUST NOT set the protocol field of Segment ID sub-TLV Type 35 and Type 36 to OSPF (value 1), as OSPFv2 is not compatible with IPv6 addresses indicated by these sub-TLVs.

mpls, routing

normative-requirement §6 SHOULD

The 'OSPF' code points in the Protocol field of the Segment ID sub-TLV and DDMAP TLV SHOULD be used only for OSPFv2, updating RFC 8287.

mpls, routing

normative-requirement §4 MAY

When the protocol field in a received Segment ID sub-TLV Type 35 or 36 is OSPF (value 1), the responder MAY treat the protocol value as 'Any IGP Protocol' (value 0) to support legacy implementations that use value 1 to indicate OSPFv3.

mpls, routing

normative-requirement §4 MUST

When the protocol field of the Segment ID sub-TLV of Type 34, 35, or 36 is set to 3, the responder MUST perform FEC validation using OSPFv3 as the IGP.

mpls, routing

protocol-element §4

OSPFv3 is assigned code point 3 in the Segment ID sub-TLV protocol field, used in sub-TLV Types 34 (IPv4 IGP-Prefix Segment ID), 35 (IPv6 IGP-Prefix Segment ID), and 36 (IGP-Adjacency Segment ID).

mpls, routing

protocol-element §5

The protocol field of the DDMAP TLV in an echo reply is set to 7 when OSPFv3 is used to distribute the label carried in the Downstream Label field.

mpls, routing

registry §7.1

IANA has assigned code point 3 (OSPFv3) in the 'Protocol in the Segment ID Sub-TLV' registry under the MPLS LSP Ping Parameters registry, and added a note to code point 1 (OSPF): 'To be used for OSPFv2 only'.

mpls, registry, routing

registry §7.2

IANA has assigned code point 7 (OSPFv3) in the 'Protocol in Label Stack Sub-TLV of Downstream Detailed Mapping TLV' registry under the MPLS LSP Ping Parameters registry, and added a note to code point 5 (OSPF): 'To be used for OSPFv2 only'.

mpls, registry, routing

security-consideration §8

This document updates RFC 8287 and does not introduce any additional security considerations. Generic security considerations for MPLS LSP Ping are covered in RFC 8029.

mpls, security