Extensions to OSPF for Advertising Prefix Administrative Tags
draft-ietf-lsr-ospf-admin-tags-00
Network Working Group A. Lindem, Ed.
Internet-Draft P. Psenak
Intended status: Standards Track Cisco Systems
Expires: July 24, 2021 January 20, 2021
Extensions to OSPF for Advertising Prefix Administrative Tags
draft-ietf-lsr-ospf-admin-tags-00
Abstract
It is useful for routers in an OSPFv2 or OSPFv3 routing domain to be
able to associate tags with prefixes. Previously, OSPFv2 and OSPFv3
were relegated to a single tag for AS External and Not-So-Stubby-Area
(NSSA) prefixes. With the flexible encodings provided by OSPFv2
Prefix/Link Attribute Advertisement and OSPFv3 Extended LSAs,
multiple administrative tags may advertised for all types of
prefixes. These administrative tags can be used for many
applications including route redistribution policy, selective prefix
prioritization, selective IP Fast-ReRoute (IPFRR) prefix protection,
and many others.
The ISIS protocol supports a similar mechanism that is described in
RFC 5130.
Status of This Memo
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This Internet-Draft will expire on July 24, 2021.
Copyright Notice
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document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
2. 32-Bit Administrative Tag Sub-TLV . . . . . . . . . . . . . . 3
3. Administrative Tag Applicability . . . . . . . . . . . . . . 4
4. Protocol Operation . . . . . . . . . . . . . . . . . . . . . 5
4.1. Equal-Cost Multipath Applicability . . . . . . . . . . . 5
5. Security Considerations . . . . . . . . . . . . . . . . . . . 5
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 6
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
8.1. Normative References . . . . . . . . . . . . . . . . . . 6
8.2. Informative References . . . . . . . . . . . . . . . . . 7
Appendix A. 64-Bit Administrative Tag Sub-TLV . . . . . . . . . 8
Appendix B. Link Administrative Tags . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction
It is useful for routers in an OSPFv2 [RFC2328] or OSPFv3 [RFC5340]
routing domain to be able to associate tags with prefixes.
Previously, OSPFv3 and OSPFv3 were relegated to a single tag for AS
External and Not-So-Stubby-Area (NSSA) prefixes. With the flexible
encodings provided by OSPFv2 Prefix/Link Attribute Advertisement
([RFC7684]) and OSPFv3 Extended LSA ([RFC8362]), multiple
administrative tags may be advertised for all types of prefixes.
These administrative tags can be used many applications including
(but not limited to):
1. Controlling which routes are redistributed into other protocols
for readvertisement.
2. Prioritizing selected prefixes for faster convergence and
installation in the forwarding plane.
3. Identifying selected prefixes for Loop-Free Alternative (LFA)
protection.
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Throughout this document, OSPF is used when the text applies to both
OSPFv2 and OSPFv3. OSPFv2 or OSPFv3 is used when the text is
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