OSPF Stub Router Advertisement
RFC 6987
Document | Type |
RFC - Informational
(September 2013; No errata)
Updated by RFC 8770
Obsoletes RFC 3137
|
|
---|---|---|---|
Authors | Alvaro Retana , Liem Nguyen , Alex Zinin , Russ White , Danny McPherson | ||
Last updated | 2020-07-29 | ||
Replaces | draft-retana-ospf-rfc3137bis | ||
Stream | Internet Engineering Task Force (IETF) | ||
Formats | plain text html pdf htmlized (tools) htmlized bibtex | ||
Reviews | |||
Stream | WG state | WG Document | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 6987 (Informational) | |
Action Holders |
(None)
|
||
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Stewart Bryant | ||
IESG note | Abhay Roy (akr@cisco.com) is the document shepherd. | ||
Send notices to | (None) | ||
IANA | IANA review state | IANA - Review Needed | |
IANA action state | No IANA Actions |
Internet Engineering Task Force (IETF) A. Retana Request for Comments: 6987 L. Nguyen Obsoletes: 3137 Cisco Systems, Inc. Category: Informational A. Zinin ISSN: 2070-1721 Cinarra Systems R. White D. McPherson Verisign, Inc. September 2013 OSPF Stub Router Advertisement Abstract This document describes a backward-compatible technique that may be used by OSPF (Open Shortest Path First) implementations to advertise a router's unavailability to forward transit traffic or to lower the preference level for the paths through such a router. This document obsoletes RFC 3137. Status of This Memo This document is not an Internet Standards Track specification; it is published for informational purposes. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Not all documents approved by the IESG are a candidate for any level of Internet Standard; see Section 2 of RFC 5741. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc6987. Retana, et al. Informational [Page 1] RFC 6987 OSPF Stub Router Advertisement September 2013 Copyright Notice Copyright (c) 2013 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 (http://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 Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1. OSPFv3-Only Solution . . . . . . . . . . . . . . . . . . 3 3. Maximum Link Metric . . . . . . . . . . . . . . . . . . . . . 4 4. Deployment Considerations . . . . . . . . . . . . . . . . . . 4 5. Security Considerations . . . . . . . . . . . . . . . . . . . 4 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 7.1. Normative References . . . . . . . . . . . . . . . . . . 5 7.2. Informative References . . . . . . . . . . . . . . . . . 5 Appendix A. Changes from RFC 3137 . . . . . . . . . . . . . . . 6 1. Introduction In some situations, it may be advantageous to inform routers in a network not to use a specific router as a transit point but to still route to it. Possible situations include the following: o The router is in a critical condition (for example, has a very high CPU load or does not have enough memory to store all Link State Advertisements (LSAs) or build the routing table). o Graceful introduction and removal of the router to/from the network. o Other (administrative or traffic engineering) reasons. Retana, et al. Informational [Page 2] RFC 6987 OSPF Stub Router Advertisement September 2013 Note that the solution introduced in this document does not remove the router from the topology view of the network (as could be done by just flushing that router's router-LSA) but discourages other routers from using it for transit routing, while still routing packets to the router's own IP addresses, i.e., the router is announced as a stub. It must be emphasized that the solution provides real benefits in networks designed with at least some level of redundancy, so that traffic can be routed around the stub router. Otherwise, traffic destined for the networks and reachable through such a stub router may still be routed through it. 2. Solutions The solution introduced in this document solves two challenges associated with the outlined problem. In the description below, router X is the router announcing itself as a stub. The challengesShow full document text