Internet-Draft | Advertise Node Ix | September 2024 |
Chen, et al. | Expires 28 March 2025 | [Page] |
- Workgroup:
- Network Working Group
- Internet-Draft:
- draft-chen-lsr-adv-ni-05
- Published:
- Intended Status:
- Standards Track
- Expires:
IGP Extensions for Advertising Node Index
Abstract
This document describes OSPF and IS-IS extensions for distributing the node index configured on a node.¶
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.¶
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 28 March 2025.¶
Copyright Notice
Copyright (c) 2024 IETF Trust and the persons identified as the document authors. All rights reserved.¶
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License.¶
1. Introduction
When the nodes in a network are numbered or indexed from 1 to the number of the nodes, an efficient stateless multicast along the shortest paths to the egresses of a P2MP tree can be achieved using the node indices of the egresses.¶
This document proposes OSPF and IS-IS extensions for distributing the node index configured on a node to support the best effort stateless multicast. When a controller such as PCE as a controller has the node indexes, it can send the P2MP tree encoded in the node indexes to the ingress of the tree.¶
1.1. Terminology
2. Extensions to OSPF
This section describes extensions to OSPF for distributing the node index configured on a node. The node index of a node MUST be unique in a network. This is like the identifier (ID) of the node.¶
[RFC7770] defines the Router Information (RI) Link state Advertisement (LSA). The RI LSA is used to advertise Optional Router Information using Router Information LSA TLVs. A new Router Information LSA TLV, called Node Index TLV, is defined to carry the Node Index configured on the node originating the RI LSA. The Node Index TLV has the following format:¶
This TLV is optional. It is applicable to both OSPFv2 and OSPFv3. For advertising a node index, the area-scoped RI LSA including a Node Index TLV is used.¶
3. Extension to IS-IS
This section describes an extension to IS-IS for distributing the Node Index configured on a node.¶
[RFC7981] defines the IS-IS Router CAPABILITY TLV to advertise Router Information. The TLV includes multiple sub-TLVs. A new Node Index sub-TLV to be included in the TLV, is defined to carry the Node Index configured on the node originating the TLV in its LSP. This sub-TLV has the following format:¶
This sub-TLV is optional. For advertising a node index, the area-scoped LSP including a Node Index sub-TLV in an IS-IS Router CAPABILITY TLV is used.¶
5. IANA Considerations
5.1. OSPF RI TLVs Registry
Under "OSPF Router Information (RI) TLVs registry" as defined in [RFC7770], IANA is requested to assign a new type as follows:¶
+==============+===================+=====================+ | Value | Description | reference | +==============+===================+=====================+ | TBD1 | Node Index | This document | +--------------+-------------------+---------------------+¶
5.2. IS-IS Sub-TLVs for TLV 242 Registry
Under "Sub-TLVs for TLV 242 (IS-IS Router CAPABILITY TLV) registry" as defined in [RFC7981], IANA is requested to assign a new sub-TLV as follows:¶
+==============+===================+=====================+ | Value | Description | reference | +==============+===================+=====================+ | TBD2 | Node Index | This document | +--------------+-------------------+---------------------+¶
6. Acknowledgements
The authors would like to thank people for their comments on this work.¶
7. Normative References
- [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>.
- [RFC7770]
- Lindem, A., Ed., Shen, N., Vasseur, JP., Aggarwal, R., and S. Shaffer, "Extensions to OSPF for Advertising Optional Router Capabilities", RFC 7770, DOI 10.17487/RFC7770, , <https://www.rfc-editor.org/info/rfc7770>.
- [RFC7981]
- Ginsberg, L., Previdi, S., and M. Chen, "IS-IS Extensions for Advertising Router Information", RFC 7981, DOI 10.17487/RFC7981, , <https://www.rfc-editor.org/info/rfc7981>.
- [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>.