One document matched: draft-raggarwa-isis-te-node-addr-00.txt

Network Working Group                                  Rahul Aggarwal
Internet Draft                                         Nischal Sheth
Expiration Date: March 2004                            Juniper Networks

            IS-IS TE Procedures for Learning Local Addresses

                draft-raggarwa-isis-te-node-addr-00.txt


1. Status of this Memo

   This document is an Internet-Draft and is in full conformance with
   all provisions of Section 10 of RFC2026.

   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
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2. Abstract

   This document describes procedures that enable a router to populate
   its Traffic Engineering Database (TED), with local addresses of other
   routers, that are not advertised in IS-IS TE extensions. The only
   addresses belonging to a router that are advertised in IS-IS TE LSAs
   are the router's local addresses on links enabled for TE and the
   Router ID. The described procedures enable a router to compute
   traffic engineered MPLS LSPs to a given router's loopback and non-TE
   capable interface addresses.










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3. Motivation

   In some cases it is desirable to setup, constrained shortest path
   first (CSPF) computed MPLS TE LSPs, to local addresses of a router
   that are not advertised in the TE LSAs i.e. loopback and non-TE
   interface addresses.

   For instance in a network carrying VPN and non-VPN traffic, its often
   desirable to use different MPLS TE LSPs for the VPN traffic and the
   non-VPN traffic. In this case one loopback address may be used as the
   BGP next-hop for VPN traffic while another may be used as the BGP
   next-hop for non-VPN traffic. Its also possible that different BGP
   sessions are used for VPN and non-VPN services. Hence two separate
   MPLS TE LSPs are desirable, one to each loopback address.

   However currently there is no defined procedure for a router to
   populate the TED with loopback or non-TE capable interface addresses
   of other routers. IS-IS TE extensions [IS-IS-TE] only advertise the
   router ID and the local addresses of TE enabled links, of a given
   router. Thus other routers in the network populate the TED only with
   these addresses.

   This document describes a procedure for populating the TED with
   loopback and non-TE interface addresses.


4. Proposed Solution

   The proposed solution is to use the local addresses learned from the
   IP Interface Address TLV [IS-IS] and the IPv6 Interface Address TLV
   [IS-IS-v6], to populate the TED. [IS-IS, IS-IS-v6] mandate including
   the IP(v6) Interface Address TLV in the IS-IS link state PDUs (LSP).
   This TLV contains a list of one or more IP(v6) addresses
   corresponding to one or more interfaces of the router which
   originates the LSP. Hence the local addresses that are not advertised
   in IS-IS TE extensions can be learned from the IP(v6) Interface
   Address TLV and used to populate the TED.

   Despite the mandatory requirement in [IS-IS] an existing
   implementation may not advertise the IP(v6) Interface Address TLV in
   its LSPs as the IP(v6) reachability information can be learned from
   the IP(v6) reachability TLVs defined in [IS-IS, IS-IS-v6]. Such an
   implementation will have to start advertising the IP(v6) Interface
   Address TLV in order to support the procedure described in this
   document.






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Internet Draft   draft-raggarwa-isis-te-node-addr-00.txt  September 2003


5. Security Considerations

   This document does not introduce any further security issues other
   than those discussed in [IS-IS, IS-IS-v6, IS-IS-TE].


6. Acknowledgments

   We would like to thank Kireeti Kompella for his contribution to this
   work. We would also like to thank Mike Shand and Robert Raszuk for
   their comments.



7. References

   [IS-IS]    "Intermediate System to Intermediate System Intra-Domain
               Routing exchange Protocol for use in Conjunction with the
               Protocol for Providing the Connectionless-mode Network
               Service (ISO 8473)", ISO 10589, 1992.

   [IS-IS-v6] C. E. Hopps, "Routing IPv6 with IS-IS",
              draft-ietf-isis-ipv6-05.txt.

   [IS-IS-TE] H. Smit, T. Li, "IS-IS extensions for Traffic
              Engineering", draft-ietf-isis-traffic-05.txt.

   [RFC]      Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.


8. Author Information


   Rahul Aggarwal
   Juniper Networks
   1194 North Mathilda Ave.
   Sunnyvale, CA 94089
   Email: rahul@juniper.net

   Nischal Sheth
   Juniper Networks
   1194 North Mathilda Ave.
   Sunnyvale, CA 94089
   Email: nsheth@juniper.net






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