IPv6 Traffic Engineering in IS-IS
RFC 6119

Internet Engineering Task Force (IETF)                       J. Harrison
Request for Comments: 6119                                     J. Berger
Category: Standards Track                                    M. Bartlett
ISSN: 2070-1721                                      Metaswitch Networks
                                                           February 2011

                   IPv6 Traffic Engineering in IS-IS

Abstract

   This document specifies a method for exchanging IPv6 traffic
   engineering information using the IS-IS routing protocol.  This
   information enables routers in an IS-IS network to calculate traffic-
   engineered routes using IPv6 addresses.

Status of This Memo

   This is an Internet Standards Track document.

   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).  Further information on
   Internet Standards is available in 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/rfc6119.

Copyright Notice

   Copyright (c) 2011 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
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   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.

Harrison, et al.             Standards Track                    [Page 1]
RFC 6119            IPv6 Traffic Engineering in IS-IS      February 2011

   This document may contain material from IETF Documents or IETF
   Contributions published or made publicly available before November
   10, 2008.  The person(s) controlling the copyright in some of this
   material may not have granted the IETF Trust the right to allow
   modifications of such material outside the IETF Standards Process.
   Without obtaining an adequate license from the person(s) controlling
   the copyright in such materials, this document may not be modified
   outside the IETF Standards Process, and derivative works of it may
   not be created outside the IETF Standards Process, except to format
   it for publication as an RFC or to translate it into languages other
   than English.

1.  Overview

   The IS-IS routing protocol is defined in [IS-IS].  Each router
   generates a Link State PDU (LSP) that contains information describing
   the router and the links from the router.  The information in the LSP
   is encoded in a variable length data structure consisting of a Type,
   Length, and Value.  Such a data structure is referred to as a TLV.

   [TE] and [GMPLS] define a number of TLVs and sub-TLVs that allow
   Traffic Engineering (TE) information to be disseminated by the IS-IS
   protocol [IS-IS].  The addressing information passed in these TLVs is
   IPv4 specific.

   [IPv6] describes how the IS-IS protocol can be used to carry out
   Shortest Path First (SPF) routing for IPv6.  It does this by defining
   IPv6-specific TLVs that are analogous to the TLVs used by IS-IS for
   carrying IPv4 addressing information.

   Multiprotocol Label Switching (MPLS) traffic engineering is very
   successful, and, as the use of IPv6 grows, there is a need to be able
   to support traffic engineering in IPv6 networks.

   This document defines the TLVs that allow traffic engineering
   information (including Generalized-MPLS (GMPLS) TE information) to be
   carried in IPv6 IS-IS networks.

2.  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 [KEYWORDS].

Harrison, et al.             Standards Track                    [Page 2]
RFC 6119            IPv6 Traffic Engineering in IS-IS      February 2011

3.  Summary of Operation

3.1.  Identifying IS-IS Links Using IPv6 Addresses

   Each IS-IS link has certain properties -- bandwidth, shared risk link
   groups (SRLGs), switching capabilities, and so on.  The IS-IS