Mechanism for Performing Label Switched Path Ping (LSP Ping) over MPLS Tunnels
RFC 6424

Internet Engineering Task Force (IETF)                        N. Bahadur
Request for Comments: 6424                                   K. Kompella
Updates: 4379                                     Juniper Networks, Inc.
Category: Standards Track                                     G. Swallow
ISSN: 2070-1721                                            Cisco Systems
                                                           November 2011

      Mechanism for Performing Label Switched Path Ping (LSP Ping)
                           over MPLS Tunnels

Abstract

   This document describes methods for performing LSP ping (specified in
   RFC 4379) traceroute over MPLS tunnels and for traceroute of stitched
   MPLS Label Switched Paths (LSPs).  The techniques outlined in RFC
   4379 are insufficient to perform traceroute Forwarding Equivalency
   Class (FEC) validation and path discovery for an LSP that goes over
   other MPLS tunnels or for a stitched LSP.  This document deprecates
   the Downstream Mapping TLV (defined in RFC 4379) in favor of a new
   TLV that, along with other procedures outlined in this document, can
   be used to trace such LSPs.

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/rfc6424.

Bahadur, et al.              Standards Track                    [Page 1]
RFC 6424               LSP Ping over MPLS Tunnels          November 2011

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Bahadur, et al.              Standards Track                    [Page 2]
RFC 6424               LSP Ping over MPLS Tunnels          November 2011

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4
     1.1.  Conventions Used in This Document  . . . . . . . . . . . .  4
   2.  Motivation . . . . . . . . . . . . . . . . . . . . . . . . . .  4
   3.  Packet Format  . . . . . . . . . . . . . . . . . . . . . . . .  5
     3.1.  Summary of Changes . . . . . . . . . . . . . . . . . . . .  5
     3.2.  New Return Codes . . . . . . . . . . . . . . . . . . . . .  6
       3.2.1.  Return Code per Downstream . . . . . . . . . . . . . .  6
       3.2.2.  Return Code for Stitched LSPs  . . . . . . . . . . . .  6
     3.3.  Downstream Detailed Mapping TLV  . . . . . . . . . . . . .  7
       3.3.1.  Sub-TLVs . . . . . . . . . . . . . . . . . . . . . . .  9
         3.3.1.1.  Multipath Data Sub-TLV . . . . . . . . . . . . . .  9
     3.4.  Deprecation of Downstream Mapping TLV  . . . . . . . . . . 13
   4.  Performing MPLS Traceroute on Tunnels  . . . . . . . . . . . . 13
     4.1.  Transit Node Procedure . . . . . . . . . . . . . . . . . . 13
       4.1.1.  Addition of a New Tunnel . . . . . . . . . . . . . . . 13
       4.1.2.  Transition between Tunnels . . . . . . . . . . . . . . 14
       4.1.3.  Modification to FEC Validation Procedure on Transit  . 16
     4.2.  Modification to FEC Validation Procedure on Egress . . . . 16
     4.3.  Ingress Node Procedure . . . . . . . . . . . . . . . . . . 17