Internet-Draft OSPFv3 Code Point for MPLS LSP Ping September 2021
Nainar, et al. Expires 27 March 2022 [Page]
Workgroup:
Network Work group
Internet-Draft:
draft-ietf-mpls-lsp-ping-ospfv3-codepoint-05
Updates:
8287 (if approved)
Published:
Intended Status:
Standards Track
Expires:
Authors:
N. Nainar
Cisco Systems, Inc.
C. Pignataro
Cisco Systems, Inc.
M. Aissaoui
Nokia

OSPFv3 CodePoint for MPLS LSP Ping

Abstract

IANA has created "Protocol in the Segment ID Sub-TLV" and "Protocol in the Label Stack Sub-TLV of the Downstream Detailed Mapping TLV" registries under the "Multi-Protocol Label Switching (MPLS) Label Switched Paths (LSPs) Ping Parameters" registry. RFC8287 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 TLV when the Interior Gateway Protocol (IGP) is OSPFv3. This document also updates RFC8287 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.

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.

Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."

This Internet-Draft will expire on 27 March 2022.

Table of Contents

1. Introduction

IANA has created the "Protocol in the Segment IS Sub-TLV" registry and "Protocol in the Label Stack Sub-TLV of the Downstream Detailed Mapping TLV" registries under the "Multi-Protocol Label Switching (MPLS) Label Switched Paths (LSPs) Ping Parameters" registry [IANA-MPLS-LSP-PING]. [RFC8287] defines the code points for OSPF and IS-IS.

"OSPF for IPv6" [RFC5340] describes OSPF version 3 (OSPFv3) to support IPv6. "Support of Address Families in OSPFv3" [RFC5838] describes the mechanism to support multiple address families (AFs) in OSPFv3. Accordingly, OSPFv3 may be used to advertise IPv6 and IPv4 prefixes.

This document specifies the code point to be used in the Segment ID sub-TLV (Type 34, 35 and 36) and in the Downstream Detailed Mapping (DDMAP) TLV when the IGP is OSPFv3.

This document also updates "Label Switched Path (LSP) Ping/Traceroute for Segment Routing (SR) IGP-Prefix and IGP-Adjacency Segment Identifiers (SIDs) with MPLS Data Planes" [RFC8287] 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.

2. Terminology

This document uses the terminology defined in "Segment Routing Architecture" [RFC8402], "Detecting Multiprotocol Label Switched (MPLS) Data-Plane Failures" [RFC8029], [RFC8287] and so the readers are expected to be familiar with the same.

3. Requirements Notation

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.

4. OSPFv3 protocol in Segment ID sub-TLVs

When the protocol field of the Segment ID sub-TLV of Type 34 (IPv4 IGP-Prefix Segment ID), Type 35 (IPv6 IGP-Prefix Segment ID) and Type 36 (IGP-Adjacency Segment ID) is set to 3, the responder MUST perform the Forwarding Equivalence Class (FEC) validation using OSPFv3 as the IGP.

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

When the protocol field in the received Segment ID sub-TLV Type 35 is OSPF (value 1), the responder MAY treat the protocol value as "Any IGP Protocol" (value 0) according to step 4a of Section 7.4 of [RFC8287]. This allows the responder to support legacy implementations that use value 1 to indicate OSPFv3.

5. OSPFv3 protocol in Downstream Detailed Mapping TLV

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

6. Update to RFC8287 - OSPFv2 Protocol in Segment ID and DDMAP sub-TLVs

Section 5 of [RFC8287] defines the code point for OSPF to be used in the Protocol field of the Segment ID sub-TLV. Section 6 of [RFC8287] defines the code point for OSPF to be used in the Protocol field of the DDMAP TLV.

This document updates [RFC8287], by specifying that the "OSPF" code points SHOULD be used only for OSPFv2.

7. IANA Considerations

7.1. Protocol in the Segment ID sub-TLV

IANA is requested to assign a new code point from the "Protocol in the Segment ID sub-TLV" registry under the "Multi-Protocol Label Switching (MPLS) Label Switched Paths (LSPs) Ping Parameters" registry as follows:

  Value        Meaning     Reference
----------     -------    ------------
  3          OSPFv3     This document

IANA is also requested to add a note for the existing entry for code point 1 (OSPF) to read: - "To be used for OSPFv2 only".

7.2. Protocol in Label Stack sub-TLV of Downstream Detailed Mapping TLV

IANA is requested to assign a new code point for OSPFv3 from "Protocol in Label Stack Sub-TLV of Downstream Detailed Mapping TLV" registry under the "Multi-Protocol Label Switching (MPLS) Label Switched Paths (LSPs) Ping Parameters" registry as follows:

  Value        Meaning      Reference
----------    ---------    ------------
  7         OSPFv3       This document

IANA is also requested to add a note for the existing codepoint 5 (OSPF) to read - "To be used for OSPFv2 only".

8. Security Considerations

This document updates [RFC8287] and does not introduce any additional security considerations. See [RFC8029] to see generic security considerations about the MPLS LSP Ping.

9. Acknowledgement

The authors would like to thank Les Ginsberg, Zafar Ali, Loa Andersson, Andrew Molotchko, Deborah Brungard, Acee Lindem and Adrian Farrel for their review and suggestions.

The authors also would like to thank Christer Holmberg, Tero Kivinen, Matthew Bocci and Tom Petch for their review comments.

10. Normative References

[IANA-MPLS-LSP-PING]
IANA, "Multi-Protocol Label Switching (MPLS) Label Switched Paths (LSPs) Ping Parameters", <http://www.iana.org/assignments/mpls-lsp-ping-parameters/mpls-lsp-ping-parameters.xhtml>.
[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/info/rfc2119>.
[RFC5340]
Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF for IPv6", RFC 5340, DOI 10.17487/RFC5340, , <https://www.rfc-editor.org/info/rfc5340>.
[RFC5838]
Lindem, A., Ed., Mirtorabi, S., Roy, A., Barnes, M., and R. Aggarwal, "Support of Address Families in OSPFv3", RFC 5838, DOI 10.17487/RFC5838, , <https://www.rfc-editor.org/info/rfc5838>.
[RFC8029]
Kompella, K., Swallow, G., Pignataro, C., Ed., Kumar, N., Aldrin, S., and M. Chen, "Detecting Multiprotocol Label Switched (MPLS) Data-Plane Failures", RFC 8029, DOI 10.17487/RFC8029, , <https://www.rfc-editor.org/info/rfc8029>.
[RFC8174]
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, , <https://www.rfc-editor.org/info/rfc8174>.
[RFC8287]
Kumar, N., Ed., Pignataro, C., Ed., Swallow, G., Akiya, N., Kini, S., and M. Chen, "Label Switched Path (LSP) Ping/Traceroute for Segment Routing (SR) IGP-Prefix and IGP-Adjacency Segment Identifiers (SIDs) with MPLS Data Planes", RFC 8287, DOI 10.17487/RFC8287, , <https://www.rfc-editor.org/info/rfc8287>.
[RFC8402]
Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L., Decraene, B., Litkowski, S., and R. Shakir, "Segment Routing Architecture", RFC 8402, DOI 10.17487/RFC8402, , <https://www.rfc-editor.org/info/rfc8402>.

Authors' Addresses

Nagendra Kumar Nainar
Cisco Systems, Inc.
7200-12 Kit Creek Road
Research Triangle Park, NC 27709
United States of America
Carlos Pignataro
Cisco Systems, Inc.
7200-11 Kit Creek Road
Research Triangle Park, NC 27709
United States of America
Mustapha Aissaoui
Nokia
Canada