Individual Vishwas Manral Internet-Draft SiNett Corp. Expires: May 26, 2005 November 26, 2004 Treating unknown Router-LSA link types draft-manral-ospf-router-lsa-unknown-type-00 Status of this Memo This document is an Internet-Draft and is subject to all provisions of section 3 of RFC 3667. By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she become aware will be disclosed, in accordance with RFC 3668. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on April 4, 2005. Copyright Notice Copyright (C) The Internet Society (2004). Abstract This document attempts to discuss and clarify the text in [OSPFv2] and [OSPFv3], about dealing with unknown link types in router LSA's. Manral, Expires May 26, 2005 [Page 1] Internet-Draft Treating unknown Router-LSA link types November 2004 1. Problem Definition The text in [OSPFv2] and [OSPFv3] does not state how to treat unknown link types when present in Router LSA's. Link-state Routing assumes that an OSPF router maintains an identical database describing the Autonomous System's topology. Incase the a Router LSA with an unknown link type is received implementations treat the LSA differently. While some implementations can ignore the link yet process the rest of the LSA others can simply ignore the LSA. This leads to different databases in the routers and hence different routing tables. 2. Changes for OSPFv2 Section 12.4.1 [OSPFv2] describes the various values used to Link-types in Router LSA's. The values 1, 2, 3 and 4 are defined. If a Router LSA with an unknown link-type is being processed, the link is ignored and the rest of the router LSA is processed normally. Section 16.1 (2)(a) [OSPFv2] should now read If this is a link to a stub network, examine the next link in V's LSA. Links to stub networks will be considered in the second stage of the shortest path calculation. If the link type is unknown examine the next link in V's LSA. Unknown Link Types are ignored. 3. Changes for OSPFv3 Section A.4.3 [OSPFv3] described the various values of Link-types in Router LSA's/ The values 1, 2 and 4 are defined to be used in routing table calculations, while 3 is reserved. Manral, Expires May 26, 2005 [Page 2] Internet-Draft Treating unknown Router-LSA link types November 2004 If a Router-LSA with an unknown or reserved link-type is being processed, the link is ignored and the rest of the router LSA is processed normally. Section 3.8.1 [OSPFv3] remains unchanged as it Refers to Section 16.1, [OSPFv2]. 4. Security Considerations This document doesn't raise any new security concerns other than those covered in [OSPFv2] and [OSPFv3]. Manral, Expires May 26, 2005 [Page 3] Internet-Draft Treating unknown Router-LSA link types November 2004 5. Normative References [OSPFv2] Moy, J., "OSPF Version 2", RFC 2328, April 1998. [OSPFv3] Moy, J., Ferguson, D. and R. Colton, "OSPF for IPv6", RFC 2740, December 1999. Authors' Addresses Vishwas Manral SiNett Corp Bangalore India EMail: vishwas@sinett.com Manral, Expires May 26, 2005 [Page 4] Internet-Draft Treating unknown Router-LSA link types November 2004 Appendix A. Acknowledgments Many thanks to Acee Lindem, Padma P., Tony Przygienda and Sina Mirtorabi for initiating the discussion. Manral, Expires May 26, 2005 [Page 5] Internet-Draft Treating unknown Router-LSA link types November 2004 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. 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Disclaimer of Validity This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Copyright Statement Copyright (C) The Internet Society (2004). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Manral, Expires May 26, 2005 [Page 6]