7950 XRS MPLS Guide R13.0 - Nokia Networks · GMPLS Configuration Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .493 Show

Alcatel-Lucent 7950EXTENSIBLE ROUTING SYSTEM | RELEASE 13.0.R4MPLS GUIDE

MPLS GUIDE

Alcatel-Lucent Proprietary & ConfidentialContains proprietary/trade secret information which is the property of Alcatel-Lucent. Not to be made available to, or copied or used by anyone who is not an employee of Alcatel-Lucent except when there is a valid non-disclosure agreement in place which covers such information and contains appropriate non-disclosure and limited use obligations.Copyright 2015 Alcatel-Lucent. All rights reserved.

All specifications, procedures, and information in this document are subject to change and revision at any time without notice. The information contained herein is believed to be accurate as of the date of publication. Alcatel-Lucent provides no warranty, express or implied, regarding its contents. Users are fully responsible for application or use of the documentation.

Alcatel, Lucent, Alcatel-Lucent and the Alcatel-Lucent logo are trademarks of Alcatel-Lucent. All other trademarks are the property of their respective owners.

Copyright 2015 Alcatel-Lucent.

All rights reserved.

Disclaimers

Alcatel-Lucent products are intended for commercial uses. Without the appropriate network design engineering, they must not be sold, licensed or otherwise distributed for use in any hazardous environments requiring fail-safe performance, such as in the operation of nuclear facilities, aircraft navigation or communication systems, air traffic control, direct life-support machines, or weapons systems, in which the failure of products could lead directly to death, personal injury, or severe physical or environmental damage. The customer hereby agrees that the use, sale, license or other distribution of the products for any such application without the prior written consent of Alcatel-Lucent, shall be at the customer's sole risk. The customer hereby agrees to defend and hold Alcatel-Lucent harmless from any claims for loss, cost, damage, expense or liability that may arise out of or in connection with the use, sale, license or other distribution of the products in such applications.

This document may contain information regarding the use and installation of non-Alcatel-Lucent products. Please note that this information is provided as a courtesy to assist you. While Alcatel-Lucent tries to ensure that this information accurately reflects information provided by the supplier, please refer to the materials provided with any non-Alcatel-Lucent product and contact the supplier for confirmation. Alcatel-Lucent assumes no responsibility or liability for incorrect or incomplete information provided about non-Alcatel-Lucent products.

However, this does not constitute a representation or warranty. The warranties provided for Alcatel-Lucent products, if any, are set forth in contractual documentation entered into by Alcatel-Lucent and its customers.

This document was originally written in English. If there is any conflict or inconsistency between the English version and any other version of a document, the English version shall prevail.

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Table of Contents

Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17About This Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17List of Technical Publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18Searching for Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

To search for specific information in this guide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19To search for specific information in multiple documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Getting StartedIn This Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23Alcatel-Lucent Router Configuration Process. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

MPLS and RSVPIn This Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25MPLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

MPLS Label Stack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28Label Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30

Label Switching Routers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31LSP Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

Bidirectional Forwarding Detection for MPLS LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33Bootstrapping the BFD Session . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33LSP BFD Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34Enabling and Implementing Limits for LSP BFD on a Node. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34BFD Configuration on RSVP-TE LSPs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35MPLS Facility Bypass Method of MPLS Fast Re-Route (FRR) . . . . . . . . . . . . . . . . . . . . . . . . . . . .37Manual Bypass LSP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37Uniform FRR Failover Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41Automatic Bandwidth Allocation for RSVP LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41

RSVP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50Using RSVP for MPLS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52

RSVP Traffic Engineering Extensions for MPLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52Hello Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52MD5 Authentication of RSVP Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53Configuring Authentication using Keychains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53

Reservation Styles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55RSVP Message Pacing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55

RSVP Overhead Refresh Reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56RSVP Graceful Restart Helper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57Enhancements to RSVP control plane congestion control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58RSVP LSP Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59P2MP RSVP-TE LSP Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

Configuring RSVP P2MP LSP Egress Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60Configuring RSVP P2MP LSP Ingress Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61Configuring Implicit Null . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62

Using Unnumbered Point-to-Point Interface in RSVP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64

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Operation of RSVP FRR Facility Backup over Unnumbered Interface. . . . . . . . . . . . . . . . . . . . . . .65MPLS Transport Profile (MPLS-TP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67

MPLS-TP Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68MPLS-TP Provider Edge and Gateway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69

VLL Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69Detailed Descriptions of MPLS-TP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71

MPLS-TP LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71MPLS-TP on Pseudowires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72

MPLS-TP Maintenance Identifiers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72Generic Associated Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76MPLS-TP Operations, Administration and Maintenance (OAM) . . . . . . . . . . . . . . . . . . . . . . . . . . .77PW Control Channel Status Notifications (Static Pseudowire Status Signaling) . . . . . . . . . . . . . . .81PW Control Channel Status Request Mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .82Pseudowire Redundancy and Active / Standby Dual Homing . . . . . . . . . . . . . . . . . . . . . . . . . . . . .83MPLS-TP LSP Protection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .83

Switching Static MPLS-TP to Dynamic T-LDP Signaled PWs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87Configuring MPLS-TP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88

Configuration Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88Node-Wide MPLS-TP Parameter Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .89Node-Wide MPLS-TP Identifier Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .89Static LSP and pseudowire (VC) Label and Tunnel Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .90Interface Configuration for MPLS-TP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .91LER Configuration for MPLS-TP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .93Intermediate LSR Configuration for MPLS-TP LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .99

MPLS-TP Show Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .101Static MPLS Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .101MPLS-TP Tunnel Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .101MPLS-TP Path configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .102MPLS-TP Protection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .106MPLS TP Node Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .106MPLS-TP Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .108

MPLS-TP Debug Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .109Traffic Engineering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .111

TE Metric (IS-IS and OSPF) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .111Admin Group Support on Facility Bypass Backup LSP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112

Procedures at Head-End Node . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112Procedures at PLR Node . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .113

Diff-Serv Traffic Engineering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .115Mapping of Traffic to a Diff-Serv LSP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .115Admission Control of Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .115RSVP Control Plane Extensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .120IGP Extensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .120Diff-Serv TE Configuration and Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .121

Diff-Serv TE LSP Class Type Change under Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .124LSP Primary Path Retry Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .124Bandwidth Sharing Across Class Types. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .127Downgrading the CT of Bandwidth Sharing LSP Paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .128Upgrading the CT of Bandwidth Sharing LSP Paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .129


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Advanced MPLS/RSVP Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .130Extending RSVP LSP to use Loopback Interfaces Other Than router-id . . . . . . . . . . . . . . . . . . . . . .130LSP Path Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .130Manual LSP Path Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .131Make-Before-Break (MBB) Procedures for LSP/Path Parameter Configuration Change . . . . . . . . . .132Automatic Creation of RSVP-TE LSP Mesh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .133RSVP-TE LSP Shortcut for IGP Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .134

Using LSP Relative Metric with IGP Shortcut. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .136ECMP Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .137Handling of Control Packets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .138Forwarding Adjacency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .138LDP Forwarding over IGP Shortcut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .139Handling of Multicast Packets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .140

RSVP-TE LSP Signaling using LSP Template . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .142Shared Risk Link Groups. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .143

Enabling Disjoint Backup Paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .143SRLG Penalty Weights for Detour and Bypass LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .145Static Configurations of SRLG Memberships . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .148

TE Graceful Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .149Soft Preemption of Diff-Serv RSVP LSP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .149Least-Fill Bandwidth Rule in CSPF ECMP Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .150Inter Area TE LSP (ERO Expansion Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .150

Area Border Node FRR Protection for Inter Area LSP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .150Inter-Area LSP support of OSPF Virtual Links . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .154Area Border Node FRR Protection for Inter Area LSP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .154

Automatic Creation of a RSVP Mesh LSP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .157Feature Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .157Feature Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .158Multi-Area and Multi-Instance Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .159Mesh LSP Name Encoding and Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .159

Timer-based Reversion for RSVP-TE LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .160Automatic Creation of an RSVP One-Hop LSP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .161

Feature Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .161Feature Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .161

Point-to-Multipoint (P2MP) RSVP LSP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .163Application in Video Broadcast . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .163P2MP LSP Data Plane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .164

Procedures at Ingress LER Node. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .164Procedures at LSR Node . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .165Procedures at Branch LSR Node . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .165Procedures at Egress LER Node . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .166Procedures at BUD LSR Node. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .166

Ingress Path Management for P2MP LSP Packets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .167Ingress P2MP Path Management on XCM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .167

RSVP Control Plane in a P2MP LSP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .169Forwarding Multicast Packets over RSVP P2MP LSP in the Base Router . . . . . . . . . . . . . . . . . . . . .172

Procedures at Ingress LER Node. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .172Procedures at Egress LER Node . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .173

MPLS Service Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .175Service Distribution Paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .175

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MPLS/RSVP Configuration Process Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .176Configuration Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .177Configuring MPLS and RSVP with CLI. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .179MPLS Configuration Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .180

LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .180Paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .180Router Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .181Choosing the Signaling Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .181

Basic MPLS Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .182Common Configuration Tasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .183

Configuring MPLS Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .184Configuring Global MPLS Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .184Configuring an MPLS Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .185Configuring MPLS Paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .186Configuring an MPLS LSP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .187

Configuring a Static LSP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .188Configuring Manual Bypass Tunnels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .189

Configuring RSVP Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .191Configuring RSVP Message Pacing Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .192Configuring Graceful Shutdown. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .193

MPLS Configuration Management Tasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .194Deleting MPLS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .194Modifying MPLS Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .194Modifying an MPLS LSP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .195Modifying MPLS Path Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .196Modifying MPLS Static LSP Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .197Deleting an MPLS Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .198

RSVP Configuration Management Tasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .199Modifying RSVP Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .199Modifying RSVP Message Pacing Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .200Deleting an Interface from RSVP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .200

MPLS/RSVP Command Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .201Command Hierarchies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .201

MPLS Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .201MPLS-TP Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .204LSP Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .205lsp-bfd Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .209MPLS Path Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .209RSVP Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .209Show Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .212Tools Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .214Router Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .214Clear Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .215Debug Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .215MPLS Configuration Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .217RSVP Configuration Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .302Show Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .325Show Router BFD session Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .398Show RSVP Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .400Tools Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .419


Table of Contents

Clear Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .433Debug Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .437

GMPLSIn This Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .445GMPLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .446

Example Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .446Use Case 1: Dynamic Connection Setup with Constraints. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .446Use Case 2: Multi-Layer Resiliency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .448

GMPLS UNI Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .449Addressing and End-to-End gLSP Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .450

1830 PSS Identifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .451Recovery Reference Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .452

End to End Recovery (IP-layer) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .453End to End ECMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .453End to End Load Sharing Using a Load Sharing GMPLS Tunnel Group . . . . . . . . . . . . . . . . . . . . . .454End to End Recovery (GMPLS Layer). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .455

Unprotected gLSP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .455Full LSP Rerouting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4561: N Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .457Optical Segment Recovery. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .459

Configuring GMPLS with CLI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .461GMPLS Configuration Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .462LMP and IPCC Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .463

Configuration of IP Communication Channels for LMP and RSVP . . . . . . . . . . . . . . . . . . . . . . . . . . .463Configuring LMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .463Configuring Traffic Engineering Links and Data Bearers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .465

Configuring MPLS Paths for GMPLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .468Configuring RSVP in GMPLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .470Configuring a GMPLS LSP on the UNI. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .472

gLSP Constraints. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .474Bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .475Shared Risk Link Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .476Optical Network Segment Recovery. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .478Configuration of End-to-End GMPLS Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .479GMPLS Tunnel Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .482Configuring IP and MPLS in an Overlay Network to Use a GMPLS LSP . . . . . . . . . . . . . . . . . . . . . . . . .484Configuration Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .485GMPLS Command Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .487

Command Hierarchies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .487LMP Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .487GMPLS Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .488GMPLS Tunnel Group Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .489Show Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .489Clear Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .490Debug Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .491Tools Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .491GMPLS Configuration Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .493Show Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .519Clear Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .526

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Debug Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .527Tools Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .533

Label Distribution ProtocolIn This Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .547Label Distribution Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .548

LDP and MPLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .548LDP Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .549Subsystem Interrelationships . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .550

Memory Manager and LDP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .551Label Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .551LDP Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .551Logger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .551Service Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .551

Execution Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .552Initialization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .552Session Lifetime . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .552

Label Exchange. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .553Other Reasons for Label Actions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .553Cleanup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .554Configuring Implicit Null Label . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .554

Global LDP Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .554Per LDP Peer FEC Import and Export Policies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .555

Configuring Multiple LDP LSR ID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .555T-LDP hello reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .557Tracking a T-LDP Peer with BFD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .557Link LDP Hello Adjacency Tracking with BFD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .557LDP LSP Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .558

TTL Security for BGP and LDP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .560ECMP Support for LDP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .561

Label Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .561Unnumbered Interface Support in LDP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .563

Feature Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .563Operation of LDP over an Unnumbered IP Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .563

Link LDP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .564Targeted LDP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .565FEC Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .565

LDP over RSVP Tunnels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .566Signaling and Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .568

LDP Label Distribution and FEC Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .568Default FEC Resolution Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .569FEC Resolution Procedure When prefer-tunnel-in-tunnel is Enabled . . . . . . . . . . . . . . . . . . . . . .569

Rerouting Around Failures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .570LDP-over-RSVP Tunnel Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .570ABR Protection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .570

LDP over RSVP Without Area Boundary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .571LDP over RSVP and ECMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .572

Class-Based Forwarding of LDP Prefix Packets over IGP Shortcuts . . . . . . . . . . . . . . . . . . . . . . . . . . . .573Configuration and Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .573

LDP ECMP Uniform Failover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .576


Table of Contents

LDP Fast-Reroute for IS-IS and OSPF Prefixes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .578LDP FRR Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .578

Reducing the Scope of the LFA Calculation by SPF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .579LDP FRR Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .580

ECMP Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .581LDP FRR and LDP Shortcut. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .581LDP FRR and LDP-over-RSVP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .582LDP FRR and RSVP Shortcut (IGP Shortcut) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .582

IS-IS and OSPF Support for Loop-Free Alternate Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .582Loop-Free Alternate Calculation in the Presence of IGP shortcuts . . . . . . . . . . . . . . . . . . . . . . . .585Loop-Free Alternate Calculation for Inter-Area/inter-Level Prefixes. . . . . . . . . . . . . . . . . . . . . . . .588Loop-Free Alternate Shortest Path First (LFA SPF) Policies . . . . . . . . . . . . . . . . . . . . . . . . . . . . .588

mLDP Fast Upstream Switchover. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .589LDP FEC to BGP Label Route Stitching. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .590

Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .591Detailed LDP FEC Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .592Detailed BGP Labeled Route Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .593Data Plane Forwarding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .593

Automatic Creation of a Targeted Hello Adjacency and LDP Session . . . . . . . . . . . . . . . . . . . . . . . . . . .594Feature Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .594Feature Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .595

Multicast P2MP LDP for GRT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .599LDP P2MP Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .600

LDP P2MP Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .600LDP P2MP Protocol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .600Make Before Break (MBB). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .600ECMP Support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .600

Multicast LDP Fast Upstream Switchover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .601Feature Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .601Feature Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .602Uniform Failover from Primary to Backup ILM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .604

Multi-Area and Multi-Instance Extensions to LDP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .606LDP Shortcut for BGP Next-Hop Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .607LDP Shortcut for IGP Routes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .608

LDP Shortcut Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .608IGP Route Resolution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .608LDP Shortcut Forwarding Plane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .609

ECMP Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .610Disabling TTL Propagation in an LSP Shortcut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .610

LDP Graceful Handling of Resource Exhaustion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .611LDP Base Graceful Handling of Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .611

LDP Enhanced Graceful Handling of Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .613LSR Overload Notification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .613LSR Overload Protection Capability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .614Procedures for LSR overload protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .615

User Guidelines and Troubleshooting Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .617Common Procedures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .617Base Resource Handling Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .618Enhanced Resource Handling Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .621

LDP IPv6 Control and Data Planes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .625

7950 XRS MPLS Guide

Table of Contents

LDP Operation in an IPv6 Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .625Link LDP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .625Targeted LDP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .626FEC Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .627LDP Session Capabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .627LDP Adjacency Capabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .629Address and FEC Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .631Controlling IPv6 FEC Distribution During an Upgrade to SROS Supporting LDP IPv6. . . . . . . . . . . .633Handling of Duplicate Link-Local IPv6 Addresses in FEC Resolution. . . . . . . . . . . . . . . . . . . . . . . . .634IGP and Static Route Synchronization with LDP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .635BFD Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .636Services Using SDP with an LDP IPv6 FEC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .637Mirror Services and Lawful Intercept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .637

Configuration at mirror source node. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .637Configuration at mirror destination node . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .638

Static Route Resolution to a LDP IPv6 FEC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .638IGP Route Resolution to a LDP IPv6 FEC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .639OAM Support with LDP IPv6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .639LDP IPv6 Interoperability Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .640

Interoperability with Implementations Compliant with draft-ietf-mpls-ldp-ipv6 . . . . . . . . . . . . . . . .640Interoperability with Implementations Compliant with RFC 5036 for IPv4 LDP ControlPlane Only . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .641

LDP Process Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .642Configuring LDP with CLI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .645LDP Configuration Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .646Basic LDP Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .647Common Configuration Tasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .648

Enabling LDP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .648Configuring FEC Originate Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .650Configuring Graceful-Restart Helper Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .651Applying Export and Import Policies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .652Targeted Session Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .654Interface Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .655Session Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .656LDP Signaling and Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .657

LDP Configuration Management Tasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .660Disabling LDP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .660Modifying Targeted Session Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .661Modifying Interface Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .662

LDP Command Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .663Configuration Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .663Show Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .667Clear Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .670Debug Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .670Tools Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .671

LDP Configuration Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .673Show LDP Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .717Clear Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .827Debug Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .830Tools Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .834


Table of Contents

Standards and Protocol Support ...................................................................................................... 839

7950 XRS MPLS Guide

Table of Contents


List of Tables

Table 1: List of Technical Publications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

Getting StartedTable 2: Configuration Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

MPLS and RSVPTable 3: Packet/Label Field Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28Table 4: Mapping from RSVP-TE to MPLS-TP Maintenance Identifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74Table 5: Bypass LSP Admin-Group Constraint Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .113Table 6: Internal TE Class Definition when Diff-Serv TE is Disabled. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .122Table 7: Default Mapping of Forwarding Class to TE Class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .122Table 8: RSVP LSP Role As Outcome of LSP level and IGP level configuration options . . . . . . . . . . . . . . .135Table 9: Impact of LSP level configuration on IGP shortcut and forwarding adjacency features . . . . . . . . .139Table 10: Impact of IGP Shortcut and Forwarding Adjacency on Unicast and Multicast RTM . . . . . . . . . . .140

GMPLSTable 11: Combinations of End-to-End and Segment Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .478

Label Distribution ProtocolTable 12: Triggering Events and the Associated Priority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .597

7950 XRS MPLS Guide

List of Tables


List of Figures

MPLS and RSVPFigure 1: Label Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28Figure 2: Label Packet Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29Figure 3: Bypass Tunnel Nodes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38Figure 4: FRR Node-Protection Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40Figure 5: Establishing LSPs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50Figure 6: LSP Using RSVP Path Set Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51Figure 7: MPLS-TP Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68Figure 8: MPLS-TP Provider Edge and Gateway, VLL Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69Figure 9: MPLS-TP Provider Edge and Gateway, spoke-SDP Termination on VPLS. . . . . . . . . . . . . . . . . . .70Figure 10: MPLS-TP Provider Edge and Gateway, spoke-SDP Termination on IES/VPRN . . . . . . . . . . . . . .70Figure 11: MPLS-TP LSR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71Figure 12: MPLS-TP Maintenance Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73Figure 13: MPLS-TP LSP and Tunnel Information Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74Figure 14: MPLS-TP PW Information Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75Figure 15: Example usage of PW Identifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76Figure 16: Label for LSP and PW G-ACh Packets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77Figure 17: BFD used for proactive CC on MPLS-TP LSP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79Figure 18: BFD used for proactive CV on MPLS-TP LSP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80Figure 19: Normal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84Figure 20: Failed Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85Figure 21: Failed Condition - Switching at A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85Figure 22: Failed Condition - Switching at Z . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86Figure 23: Static - Dynamic PW Switching with MPLS-TP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87Figure 24: RDM with Two Class Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .118Figure 25: First LSP Reservation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .118Figure 26: Second LSP Reservation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .119Figure 27: RDM Admission Control Policy Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .127Figure 28: Sharing bandwidth when an LSP primary path is downgraded to backup CT . . . . . . . . . . . . . . .128Figure 29: Sharing Bandwidth When an LSP Primary Path is Upgraded to Main CT . . . . . . . . . . . . . . . . . .129Figure 30: Shared Risk Link Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .145Figure 31: SRLG Penalty Weight Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .146Figure 32: Automatic ABR Node Selection for Inter-Area LSP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .151Figure 33: ABR Node Protection Using Dynamic Bypass LSP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .155Figure 34: Application of P2MP LSP in Video Broadcast . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .163Figure 35: MPLS and RSVP Configuration and Implementation Flow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .176

GMPLSFigure 36: Dynamic Connection Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .447Figure 37: Multi-Layer Resiliency. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .448Figure 38: GMPLS UNI Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .449Figure 39: Identifier Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .451Figure 40: General GMPLS UNI Interconnection Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .452Figure 41: End-to-End ECMP with gLSP Diversity Across Single UNI-C . . . . . . . . . . . . . . . . . . . . . . . . . . .454Figure 42: End-to-End Load Sharing GMPLS Tunnel Group with gLSP Path Diversity . . . . . . . . . . . . . . . .455

7950 XRS MPLS Guide

List of Figures

Figure 43: gLSP Re-Establishment (PATH Refresh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .456Figure 44: Full LSP Rerouting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .457Figure 45: 1:N Protection, with N=1 (RFC4872) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .458Figure 46: N>1 Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .458Figure 47: Optical Segment Protection Domain. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .459Figure 48: SRLG Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .476

Label Distribution ProtocolFigure 49: Subsystem Interrelationships . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .550Figure 50: LDP Adjacency and Session over Unnumbered Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .563Figure 51: LDP over RSVP Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .566Figure 52: LDP over RSVP Application Variant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .567Figure 53: LDP over RSVP Without ABR Stitching Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .571Figure 54: Topology with Primary and LFA Routes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .583Figure 55: Example Topology with Broadcast Interfaces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .584Figure 56: Application of LDP to BGP FEC Stitching. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .590Figure 57: Video Distribution using P2MP LDP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .599Figure 58: mLDP LSP with Backup Upstream LSR Nodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .603Figure 59: LSR Overload Status TLV (Type = 0x3E02). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .614Figure 60: LSR Overload Protection Capability TLV (Type== 0x3E03). . . . . . . . . . . . . . . . . . . . . . . . . . . . .615Figure 61: LDP Adjacency and Session over an IPv6 Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .625Figure 62: LDP IPv6 Address and FEC Distribution Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .632Figure 63: LDP IPv6 Address and FEC Distribution Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .633Figure 64: LDP Configuration and Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .643

Preface

About This GuideThis guide describes the services and protocol support provided by the router and presents examples to configure and implement MPLS, RSVP, GMPLS, and LDP protocols.

This guide is organized into functional chapters and provides concepts and descriptions of the implementation flow, as well as Command Line Interface (CLI) syntax and command usage.

Audience

This guide is intended for network administrators who are responsible for configuring the 7950 XRS routers. It is assumed that the network administrators have an understanding of networking principles and configurations. Concepts described in this guide include the following:

Multiprotocol Label Switching (MPLS) Resource Reservation Protocol (RSVP) Generalized Multiprotocol Label Switching (GMPLS) Label Distribution Protocol (LDP)


Preface

List of Technical Publications

The 7950 XRS documentation set is composed of the following guides:

Table 1: List of Technical Publications

Guide Description

7950 XRS Basic System Configuration Guide This guide describes basic system configurations and operations.

7950 XRS System Management Guide This guide describes system security and access configurations as well as event logging and accounting logs.

7950 XRS Interface Configuration Guide This guide describes XMA Control Module (XCM), XRS Media Adaptor (XMA), port and Link Aggregation Group (LAG) provisioning.

7950 XRS Router Configuration Guide This guide describes logical IP routing interfaces and associated attributes such as an IP address, as well as IP and MAC-based filtering, and VRRP and Cflowd.

7950 XRS Routing Protocols Guide This guide provides an overview of routing concepts and provides configuration examples for RIP, OSPF, IS-IS, BGP, and route policies.

7950 XRS MPLS Guide This guide describes how to configure Multiprotocol Label Switching (MPLS) and Label Distribution Protocol (LDP).

7950 XRS Services Guide This guide describes how to configure service parameters such as service distribution points (SDPs), customer information, and user services.

7950 XRS Layer 2 Services and EVPN Guide: VLL, VPLS, PBB, and EVPN

This guide describes Virtual Leased Lines (VLL), Virtual Private LAN Service (VPLS), Provider Backbone Bridging (PBB), and Ethernet VPN (EVPN).

7950 XRS Layer 3 Services Guide: Internet Enhanced Services and Virtual Private Routed Network Services

This guide describes Internet Enhanced Services (IES) and Virtual Private Routed Network (VPRN) services.

Page 18 7950 XRS MPLS Guide

Preface

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7950 XRS OAM and Diagnostics Guide This guide describes how to configure features such as service mirroring and Operations, Administration and Management (OAM) tools.

7950 XRS Quality of Service Guide This guide describes how to configure Quality of Service (QoS) policy management.

Table 1: List of Technical Publications

Guide Description


Preface

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Preface

Technical Support

If you purchased a service agreement for your 7950 SR-Series router and related products from a distributor or authorized reseller, contact the technical support staff for that distributor or reseller for assistance. If you purchased an Alcatel-Lucent service agreement, follow this link to contact an Alcatel-Lucent support representative and to access product manuals and documentation updates:

https://support2.alcatel-lucent.com/portal/olcsHome.do


Preface


GETTING STARTED

In This ChapterThis chapter provides process flow information to configure MPLS, RSVP, GMPLS, and LDP protocols.

Alcatel-Lucent Router Configuration ProcessTable 2 lists the tasks necessary to configure MPLS applications functions.

This guide is presented in an overall logical configuration flow. Each section describes a software area and provides CLI syntax and command usage to configure parameters for a functional area.

Note: In SR OS 12.0.R4 any function that displays an IPv6 address or prefix changes to reflect rules described in RFC 5952, A Recommendation for IPv6 Address Text Representation. Specifically, hexadecimal letters in IPv6 addresses are now represented in lowercase, and the correct compression of all leading zeros is displayed. This changes visible display output

Table 2: Configuration Process

Area Task Chapter

Protocol configuration Configure MPLS protocols:

MPLS MPLS on page 27

RSVP RSVP on page 50

GMPLS GMPLS on page 445

LDP Label Distribution Protocol on page 548

Reference List of IEEE, IETF, and other proprietary entities.

Standards and Protocol Support on page 839


Getting Started

compared to previous SR OS releases. Previous SR OS behavior can cause issues with operator scripts that use standard IPv6 address expressions and with libraries that have standard IPv6 parsing as per RFC 5952 rules. See the section on IPv6 Addresses in the Router Configuration Guide for more information.


MPLS and RSVP

In This ChapterThis chapter provides information to configure MPLS and RSVP.

MPLS on page 27 MPLS Label Stack on page 28 Label Switching Routers on page 31

RSVP on page 50 Using RSVP for MPLS on page 52 Reservation Styles on page 55 RSVP Overhead Refresh Reduction on page 56 RSVP Graceful Restart Helper on page 57 Enhancements to RSVP control plane congestion control on page 58 RSVP LSP Statistics on page 59

MPLS Transport Profile (MPLS-TP) on page 67 Traffic Engineering on page 111

TE Metric (IS-IS and OSPF) on page 111 Diff-Serv Traffic Engineering on page 115 Diff-Serv TE LSP Class Type Change under Failure on page 124

Advanced MPLS/RSVP Features on page 130 LSP Path Change on page 130 Make-Before-Break (MBB) Procedures for LSP/Path Parameter Configuration

Change on page 132 Automatic Creation of RSVP-TE LSP Mesh on page 133 RSVP-TE LSP Shortcut for IGP Resolution on page 134 Shared Risk Link Groups on page 143 TE Graceful Shutdown on page 149


In This Chapter

Soft Preemption of Diff-Serv RSVP LSP on page 149 Least-Fill Bandwidth Rule in CSPF ECMP Selection on page 150 Inter Area TE LSP (ERO Expansion Method) on page 150 Automatic Creation of a RSVP Mesh LSP on page 157 Timer-based Reversion for RSVP-TE LSPs on page 160

Automatic Creation of an RSVP One-Hop LSP on page 161 Point-to-Multipoint (P2MP) RSVP LSP on page 163

Application in Video Broadcast on page 163 P2MP LSP Data Plane on page 164 Ingress Path Management for P2MP LSP Packets on page 167 RSVP Control Plane in a P2MP LSP on page 169 Forwarding Multicast Packets over RSVP P2MP LSP in the Base Router on page 172

MPLS Service Usage on page 175 Service Distribution Paths on page 175

MPLS/RSVP Configuration Process Overview on page 176 Configuration Notes on page 177


MPLS and RSVP

MPLS

Multiprotocol Label Switching (MPLS) is a label switching technology that provides the ability to set up connection-oriented paths over a connectionless IP network. MPLS facilitates network traffic flow and provides a mechanism to engineer network traffic patterns independently from routing tables. MPLS sets up a specific path for a sequence of packets. The packets are identified by a label inserted into each packet. MPLS is not enabled by default and must be explicitly enabled.

MPLS is independent of any routing protocol but is considered multiprotocol because it works with the Internet Protocol (IP), Asynchronous Transport Mode (ATM), and frame relay network protocols.


MPLS Label Stack

MPLS Label Stack

MPLS requires a set of procedures to enhance network layer packets with label stacks which thereby turns them into labeled packets. Routers that support MPLS are known as Label Switching Routers (LSRs). In order to transmit a labeled packet on a particular data link, an LSR must support the encoding technique which, when given a label stack and a network layer packet, produces a labeled packet.

In MPLS, packets can carry not just one label, but a set of labels in a stack. An LSR can swap the label at the top of the stack, pop the stack, or swap the label and push one or more labels into the stack. The processing of a labeled packet is completely independent of the level of hierarchy. The processing is always based on the top label, without regard for the possibility that some number of other labels may have been above it in the past, or that some number of other labels may be below it at present.

As described in RFC 3032, MPLS Label Stack Encoding, the label stack is represented as a sequence of label stack entries. Each label stack entry is represented by 4 octets. Figure 1 displays the label placement in a packet.

Figure 1: Label Placement

0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0

0 2

Label 1 Exp S TTL

2 3

1

OSSG013

Table 3: Packet/Label Field Description

Field Description

Label This 20-bit field carries the actual value (unstructured) of the label.

Exp This 3-bit field is reserved for experimental use. It is currently used for Class of Service (CoS).

S This bit is set to 1 for the last entry (bottom) in the label stack, and 0 for all other label stack entries.

TTL This 8-bit field is used to encode a TTL value.


MPLS and RSVP

A stack can carry several labels, organized in a last in/first out order. The top of the label stack appears first in the packet and the bottom of the stack appears last (Figure 2).

Figure 2: Label Packet Placement

The label value at the top of the stack is looked up when a labeled packet is received. A successful lookup reveals:

The next hop where the packet is to be forwarded. The operation to be performed on the label stack before forwarding.

In addition, the lookup may reveal outgoing data link encapsulation and other information needed to properly forward the packet.

An empty label stack can be thought of as an unlabeled packet. An empty label stack has zero (0) depth. The label at the bottom of the stack is referred to as the Level 1 label. The label above it (if it exists) is the Level 2 label, and so on. The label at the top of the stack is referred to as the Level m label.

Labeled packet processing is independent of the level of hierarchy. Processing is always based on the top label in the stack which includes information about the operations to perform on the packet's label stack.

OSSG014

Layer 2 Header Top Label Bottom Label Data Packet


MPLS Label Stack

Label Values

Packets traveling along an LSP (see Label Switching Routers on page 31) are identified by its label, the 20-bit, unsigned integer. The range is 0 through 1,048,575. Label values 0-15 are reserved and are defined below as follows:

A value of 0 represents the IPv4 Explicit NULL Label. This Label value is legal only at the bottom of the Label stack. It indicates that the Label stack must be popped, and the packet forwarding must be based on the IPv4 header.

A value of 1 represents the router alert Label. This Label value is legal anywhere in the Label stack except at the bottom. When a received packet contains this Label value at the top of the Label stack, it is delivered to a local software module for processing. The actual packet forwarding is determined by the Label beneath it in the stack. However, if the packet is further forwarded, the router alert Label should be pushed back onto the Label stack before forwarding. The use of this Label is analogous to the use of the router alert option in IP packets. Since this Label cannot occur at the bottom of the stack, it is not associated with a particular network layer protocol.

A value of 2 represents the IPv6 explicit NULL Label. This Label value is only legal at the bottom of the Label stack. It indicates that the Label stack must be popped, and the packet forwarding must be based on the IPv6 header.

A value of 3 represents the Implicit NULL Label. This is a Label that a Label Switching Router (LSR) can assign and distribute, but which never actually appears in the encapsulation. When an LSR would otherwise replace the Label at the top of the stack with a new Label, but the new Label is Implicit NULL, the LSR pops the stack instead of doing the replacement. Although this value may never appear in the encapsulation, it needs to be specified in the Label Distribution Protocol (LDP), so a value is reserved.

Values 4-15 are reserved for future use.

The router uses labels for MPLS, RSVP-TE, and LDP, as well as packet-based services such as VLL and VPLS.

Label values 16 through 1,048,575 are defined as follows:

Label values 16 through 31 are reserved for future use. Label values 32 through 1,023 are available for static LSP label assignments. Label values 1,024 through 2,047 are reserved for future use. Label values 2,048 through 18,431 are available for static service label assignments Label values 18,432 through 262,143 are assigned dynamically by RSVP, LDP, and BGP

control planes for both MPLS LSP and service labels. Label values 262,144 through 1,048,575 are reserved for future use.


MPLS and RSVP

Label Switching Routers

LSRs perform the label switching function. LSRs perform different functions based on its position in an LSP. Routers in an LSP do one of the following:

The router at the beginning of an LSP is the ingress label edge router (ILER). The ingress router can encapsulate packets with an MPLS header and forward it to the next router along the path. An LSP can only have one ingress router.

A Label Switching Router (LSR) can be any intermediate router in the LSP between the ingress and egress routers. An LSR swaps the incoming label with the outgoing MPLS label and forwards the MPLS packets it receives to the next router in the MPLS path (LSP). An LSP can have 0-253 transit routers.

The router at the end of an LSP is the egress label edge router (ELER). The egress router strips the MPLS encapsulation which changes it from an MPLS packet to a data packet, and then forwards the packet to its final destination using information in the forwarding table. Each LSP can have only one egress router. The ingress and egress routers in an LSP cannot be the same router.

A router in your network can act as an ingress, egress, or transit router for one or more LSPs, depending on your network design.

An LSP is confined to one IGP area for LSPs using constrained-path. They cannot cross an autonomous system (AS) boundary.

Static LSPs can cross AS boundaries. The intermediate hops are manually configured so the LSP has no dependence on the IGP topology or a local forwarding table.

LSP Types

The following are LSP types:

Static LSPs A static LSP specifies a static path. All routers that the LSP traverses must be configured manually with labels. No signaling such as RSVP or LDP is required.

Signaled LSP LSPs are set up using a signaling protocol such as RSVP-TE or LDP. The signaling protocol allows labels to be assigned from an ingress router to the egress router. Signaling is triggered by the ingress routers. Configuration is required only on the ingress router and is not required on intermediate routers. Signaling also facilitates path selection.

There are two signaled LSP types: Explicit-path LSPs MPLS uses RSVP-TE to set up explicit path LSPs. The hops

within the LSP are configured manually. The intermediate hops must be configured as either strict or loose meaning that the LSP must take either a direct path from the


Label Switching Routers

previous hop router to this router (strict) or can traverse through other routers (loose). You can control how the path is set up. They are similar to static LSPs but require less configuration. See RSVP on page 50.

Constrained-path LSPs The intermediate hops of the LSP are dynamically assigned. A constrained path LSP relies on the Constrained Shortest Path First (CSPF) routing algorithm to find a path which satisfies the constraints for the LSP. In turn, CSPF relies on the topology database provided by the extended IGP such as OSPF or IS-IS. Once the path is found by CSPF, RSVP uses the path to request the LSP set up. CSPF calculates the shortest path based on the constraints provided such as bandwidth, class of service, and specified hops.

If fast reroute is configured, the ingress router signals the routers downstream. Each downstream router sets up a detour for the LSP. If a downstream router does not support fast reroute, the request is ignored and the router continues to support the LSP. This can cause some of the detours to fail, but otherwise the LSP is not impacted.

No bandwidth is reserved for the rerouted path. If the user enters a value in the bandwidth parameter in the config>router>mpls>lsp>fast-reroute context, it will have no effect on the LSP backup LSP establishment.

Hop-limit parameters specifies the maximum number of hops that an LSP can traverse, including the ingress and egress routers. An LSP is not set up if the hop limit is exceeded. The hop count is set to 255 by default for the primary and secondary paths. It is set to 16 by default for a bypass or detour LSP path.


MPLS and RSVP

Bidirectional Forwarding Detection for MPLS LSPs

BFD for MPLS LSPs enables BFD to monitor the LSP between its LERs, irrespective of how many LSRs the LSP may traverse. Therefore, it enables faults that are local to individual LSPs to be detected, whether or not they also affect forwarding for other LSPs or IP packet flows. This makes it ideal for monitoring LSPs carrying specific high-value services, where detecting forwarding failures in the minimal amount of time is critical. The system will raise an SNMP trap, as well as indicate the BFD session state in show and tools dump commands if a LSP BFD session goes down.

The system supports LSP BFD on RSVP LSPs. BFD packets are encapsulated in an MPLS label stack corresponding to the FEC that the BFD session is associated with, as per Section 7 of [RFC5884].

Since RSVP LSPs are unidirectional, a routed return path is used for the BFD control packets from the egress LER towards the ingress LER.

Bootstrapping the BFD Session

A BFD session on an LSP is bootstrapped using LSP Ping. LSP Ping is used to exchange the local/remote discriminator values to use for the BFD session for a particular .

The process is as follows:

1. The ingress LER sends an LSP ping to egress LSR, including the BFD Discriminator TLV with the local discriminator value.

2. The egress LER validates the received FEC. If this is true, then the Egress LSR sends a BFD control packet to the ingress LSR with the your discriminator field set to the value of the local discriminator in the received LSP Ping, and my discriminator field set to the locally assigned discriminator value. This BFD control packet will be routed to the ingress LSR.

3. The ingress LER then follows normal BFD procedures in response to t