Label Distribution Protocol Extensions for Point-to-Multipoint and Multipoint-to-Multipoint Label Switched Paths
RFC 6388

Internet Engineering Task Force (IETF)                 IJ. Wijnands, Ed.
Request for Comments: 6388                           Cisco Systems, Inc.
Category: Standards Track                                  I. Minei, Ed.
ISSN: 2070-1721                                              K. Kompella
                                                        Juniper Networks
                                                               B. Thomas
                                                           November 2011

               Label Distribution Protocol Extensions for
 Point-to-Multipoint and Multipoint-to-Multipoint Label Switched Paths

Abstract

   This document describes extensions to the Label Distribution Protocol
   (LDP) for the setup of point-to-multipoint (P2MP) and multipoint-to-
   multipoint (MP2MP) Label Switched Paths (LSPs) in MPLS networks.
   These extensions are also referred to as multipoint LDP.  Multipoint
   LDP constructs the P2MP or MP2MP LSPs without interacting with or
   relying upon any other multicast tree construction protocol.
   Protocol elements and procedures for this solution are described for
   building such LSPs in a receiver-initiated manner.  There can be
   various applications for multipoint LSPs, for example IP multicast or
   support for multicast in BGP/MPLS Layer 3 Virtual Private Networks
   (L3VPNs).  Specification of how such applications can use an LDP
   signaled multipoint LSP is outside the scope of this document.

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/rfc6388.

Wijnands, et al.             Standards Track                    [Page 1]
RFC 6388            P2MP and MP2MP LSP Setup with LDP      November 2011

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Table of Contents

   1. Introduction ....................................................3
      1.1. Conventions Used in This Document ..........................4
      1.2. Terminology ................................................4
      1.3. Manageability ..............................................5
   2. Setting Up P2MP LSPs with LDP ...................................6
      2.1. Support for P2MP LSP Setup with LDP ........................6
      2.2. The P2MP FEC Element .......................................6
      2.3. The LDP MP Opaque Value Element ............................8
           2.3.1. The Generic LSP Identifier ..........................9
      2.4. Using the P2MP FEC Element .................................9
           2.4.1. Label Mapping ......................................10
           2.4.2. Label Withdraw .....................................12
           2.4.3. Upstream LSR Change ................................13
   3. Setting up MP2MP LSPs with LDP .................................14
      3.1. Support for MP2MP LSP Setup with LDP ......................14
      3.2. The MP2MP Downstream and Upstream FEC Elements ............15
      3.3. Using the MP2MP FEC Elements ..............................15