MPLS Applications Configuration Guide

Junos® OS
MPLS Applications Configuration Guide
Release
11.4
Published: 2011-11-15
Copyright © 2011, Juniper Networks, Inc.
Juniper Networks, Inc.
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®
Junos OS MPLS Applications Configuration Guide
Release 11.4
Copyright © 2011, Juniper Networks, Inc.
All rights reserved.
Revision History
October 2011—R1 Junos OS 11.4
The information in this document is current as of the date listed in the revision history.
YEAR 2000 NOTICE
Juniper Networks hardware and software products are Year 2000 compliant. Junos OS has no known time-related limitations through the
year 2038. However, the NTP application is known to have some difficulty in the year 2036.
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The Juniper Networks product that is the subject of this technical documentation consists of (or is intended for use with) Juniper Networks
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http://www.juniper.net/support/eula.html. By downloading, installing or using such software, you agree to the terms and conditions
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Copyright © 2011, Juniper Networks, Inc.
Abbreviated Table of Contents
About This Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxvii
Part 1
Overview
Chapter 1
Traffic Engineering Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Chapter 2
Complete MPLS Applications Configuration Statements . . . . . . . . . . . . . . . . 9
Part 2
MPLS
Chapter 3
MPLS Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Chapter 4
MPLS Router Configuration Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Chapter 5
MPLS-Signaled LSP Configuration Guidelines . . . . . . . . . . . . . . . . . . . . . . . 125
Chapter 6
DiffServ-Aware Traffic Engineering Configuration Guidelines . . . . . . . . . . 169
Chapter 7
Static and Explicit-Path LSP Configuration Guidelines . . . . . . . . . . . . . . . . 193
Chapter 8
Point-to-Multipoint LSP Configuration Guidelines . . . . . . . . . . . . . . . . . . . 203
Chapter 9
Miscellaneous MPLS Properties Configuration Guidelines . . . . . . . . . . . . . 213
Chapter 10
Summary of MPLS Configuration Statements . . . . . . . . . . . . . . . . . . . . . . . 239
Part 3
RSVP
Chapter 11
RSVP Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
Chapter 12
RSVP Configuration Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
Chapter 13
Summary of RSVP Configuration Statements . . . . . . . . . . . . . . . . . . . . . . . 387
Part 4
LDP
Chapter 14
LDP Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425
Chapter 15
LDP Configuration Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433
Chapter 16
Summary of LDP Configuration Statements . . . . . . . . . . . . . . . . . . . . . . . . 465
Part 5
CCC and TCC
Chapter 17
CCC and TCC Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 501
Chapter 18
CCC and TCC Configuration Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 505
Chapter 19
Summary of CCC and TCC Configuration Statements . . . . . . . . . . . . . . . . . 527
Part 6
GMPLS
Chapter 20
GMPLS Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 541
Chapter 21
GMPLS Configuration Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 547
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
Chapter 22
Hierarchy of RSVP LSPs Configuration Guidelines . . . . . . . . . . . . . . . . . . . . 563
Chapter 23
Summary of GMPLS Configuration Statements . . . . . . . . . . . . . . . . . . . . . 569
Part 7
Indexes
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 589
Index of Statements and Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 609
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Copyright © 2011, Juniper Networks, Inc.
Table of Contents
About This Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxvii
Junos OS Documentation and Release Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . xxvii
Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxviii
Audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxviii
Supported Platforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxviii
Using the Indexes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxix
Using the Examples in This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxix
Merging a Full Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxix
Merging a Snippet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxx
Documentation Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxx
Documentation Feedback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxii
Requesting Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxii
Self-Help Online Tools and Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxiii
Opening a Case with JTAC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxiii
Part 1
Overview
Chapter 1
Traffic Engineering Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Traffic Engineering Capabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Components of Traffic Engineering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Packet Forwarding Component . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Packet Forwarding Based on Label Swapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
How a Packet Traverses an MPLS Backbone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Information Distribution Component . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Path Selection Component . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Offline Planning and Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Signaling Component . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Flexible LSP Calculation and Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Chapter 2
Complete MPLS Applications Configuration Statements . . . . . . . . . . . . . . . . 9
[edit logical-systems] Hierarchy Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
[edit protocols connections] Hierarchy Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
[edit protocols ldp] Hierarchy Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
[edit protocols link-management] Hierarchy Level . . . . . . . . . . . . . . . . . . . . . . . . . 12
[edit protocols mpls] Hierarchy Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
[edit protocols rsvp] Hierarchy Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
Part 2
MPLS
Chapter 3
MPLS Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
MPLS Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Supported MPLS Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Link-Layer Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
MPLS and Traffic Engineering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Label Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Special Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Label Allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Operations on Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Routers in an LSP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
How a Packet Travels Along an LSP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Types of LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Scope of LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Constrained-Path LSP Computation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
How CSPF Selects a Path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Path Selection Tie-Breaking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Computing Paths Offline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
LSPs on an Overloaded Router . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Fate Sharing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
SRLG Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
IGP Shortcuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Enabling IGP Shortcuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
LSPs Qualified in Shortcut Computations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
IGP Shortcut Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
IGP Shortcuts and Routing Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
IGP Shortcuts and VPNs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Advertising LSPs into IGPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
IP and MPLS Packets on Aggregated Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
MPLS Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
BGP Destinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
IGP and BGP Destinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Selecting a Forwarding LSP Next Hop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
MPLS and Routing Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
MPLS and Traffic Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Fast Reroute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Fast Reroute Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Detour Merging Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Detour Computations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Fast Reroute Path Optimization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Automatic Bandwidth Allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Point-to-Multipoint LSPs Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
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Copyright © 2011, Juniper Networks, Inc.
Table of Contents
Chapter 4
MPLS Router Configuration Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Minimum MPLS Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Configuring the Ingress Router for MPLS-Signaled LSPs . . . . . . . . . . . . . . . . . . . . 56
Creating Named Paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Examples: Creating Named Paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Configuring Alternate Backup Paths Using Fate Sharing . . . . . . . . . . . . . . . . 58
Configuring Fate Sharing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Implications for CSPF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Example: Configuring Fate Sharing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Example: Configuring a Constrained-Path LSP for Which Junos OS Makes All
Forwarding Decisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Example: Configuring an Explicit-Path LSP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Example: Configuring a Constrained-Path LSP for Which Junos OS Makes Most
Forwarding Decisions and Considers Hop Constraints . . . . . . . . . . . . . . . . . . 62
Example: Configuring a Constrained-Path LSP for Which Junos OS Makes Most
Forwarding Decisions and the Secondary Path Is Explicit . . . . . . . . . . . . . . . 62
Configuring the Intermediate and Egress Routers for MPLS-Signaled LSPs . . . . . 63
Improving Traffic Engineering Database Accuracy with RSVP PathErr
Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
PathErr Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Identifying the Problem Link . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Configuring the Router to Improve Traffic Engineering Database
Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Configuring MPLS-Signaled LSPs to Use GRE Tunnels . . . . . . . . . . . . . . . . . . . . . 66
Example: Configuring MPLS-Signaled LSPs to Use GRE Tunnels . . . . . . . . . 66
Tunneling IPv6 Traffic over MPLS IPv4 Networks . . . . . . . . . . . . . . . . . . . . . . . . . . 67
IPv6 over MPLS Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Configuring IPv4 MPLS Tunnels to Carry IPv6 Traffic . . . . . . . . . . . . . . . . . . . 69
Configuring IPv6 on Both Core-Facing and CE Router-Facing
Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Configuring MPLS and RSVP Between PE Routers . . . . . . . . . . . . . . . . . 69
Enabling IPv6 Tunneling on PE Routers . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Configuring Multiprotocol BGP to Carry IPv6 Traffic . . . . . . . . . . . . . . . . 70
Configuring ICMP Message Tunneling for MPLS . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Example: Configuring SRLG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Example: Excluding SRLG Links Completely for the Secondary LSP . . . . . . . . . . . 80
Example: Configuring SRLG With Link Protection . . . . . . . . . . . . . . . . . . . . . . . . . 85
Example: Configuring SRLG With Link Protection With the exclude-srlg
Option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Chapter 5
MPLS-Signaled LSP Configuration Guidelines . . . . . . . . . . . . . . . . . . . . . . . 125
LSP Configuration Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Configuring the Ingress and Egress Router Addresses for LSPs . . . . . . . . . . . . . . 129
Configuring the Ingress Router Address for LSPs . . . . . . . . . . . . . . . . . . . . . . 129
Configuring the Egress Router Address for LSPs . . . . . . . . . . . . . . . . . . . . . . 130
Preventing the Addition of Egress Router Addresses to Routing Tables . . . . 130
Configuring Primary and Secondary LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Configuring Primary and Secondary Paths for an LSP . . . . . . . . . . . . . . . . . . 132
Configuring the Revert Timer for LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
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Junos OS 11.4 MPLS Applications Configuration Guide
Specifying the Conditions for Path Selection . . . . . . . . . . . . . . . . . . . . . . . . . 133
Configuring a Text Description for LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
Configuring Fast Reroute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
Configuring the Optimization Interval for Fast Reroute Paths . . . . . . . . . . . . . . . 136
Adding LSP-Related Routes to the inet.3 Routing Table . . . . . . . . . . . . . . . . . . . . 136
Configuring the Connection Between Ingress and Egress Routers . . . . . . . . . . . . 137
Configuring LSP Metrics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Configuring Dynamic LSP Metrics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Configuring Static LSP Metrics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Configuring CSPF Tie Breaking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Configuring Load Balancing Based on MPLS Labels . . . . . . . . . . . . . . . . . . . . . . 140
Disabling Normal TTL Decrementing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
Configuring MPLS Soft Preemption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Configuring Automatic Bandwidth Allocation for LSPs . . . . . . . . . . . . . . . . . . . . 145
Configuring MPLS Statistics for Automatic Bandwidth Allocation . . . . . . . . 146
Configuring Automatic Bandwidth Allocation on LSPs . . . . . . . . . . . . . . . . . 147
Configuring the Automatic Bandwidth Allocation Interval . . . . . . . . . . . 147
Configuring the Maximum and Minimum Bounds of the LSP’s
Bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
Configuring the Automatic Bandwidth Adjustment Threshold . . . . . . . 148
Configuring a Limit on Bandwidth Overflow Samples . . . . . . . . . . . . . . 149
Configuring Passive Bandwidth Utilization Monitoring . . . . . . . . . . . . . . 151
Requesting Automatic Bandwidth Allocation Adjustment . . . . . . . . . . . . . . . 151
Disabling Constrained-Path LSP Computation . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
Configuring Administrative Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
Configuring Extended Administrative Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
Configuring Preference Values for LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
Disabling Path Route Recording . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
Configuring Class of Service for MPLS LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
Class of Service for MPLS Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
Configuring the MPLS CoS Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
Rewriting IEEE 802.1p Packet Headers with the MPLS CoS Value . . . . . . . . 159
Configuring Adaptive LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
Configuring Priority and Preemption for LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
Optimizing Signaled LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
Configuring the Smart Optimize Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
Limiting the Number of Hops in LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
Configuring the Bandwidth Value for LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
Configuring Hot Standby of Secondary Paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
Damping Advertisement of LSP State Changes . . . . . . . . . . . . . . . . . . . . . . . . . . 167
Chapter 6
DiffServ-Aware Traffic Engineering Configuration Guidelines . . . . . . . . . . 169
DiffServ-Aware Traffic Engineering Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 170
DiffServ-Aware Traffic Engineering Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
DiffServ-Aware Traffic Engineering Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 170
DiffServ-Aware Traffic Engineering Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
DiffServ-Aware Traffic Engineered LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
DiffServ-Aware Traffic Engineered LSPs Overview . . . . . . . . . . . . . . . . . . . . . . . . 172
DiffServ-Aware Traffic Engineered LSPs Operation . . . . . . . . . . . . . . . . . . . . . . . 173
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Multiclass LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
Multiclass LSP Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
Establishing a Multiclass LSP on the Differentiated Services Domain . . . . . . . . . 174
Configuring Routers for DiffServ-Aware Traffic Engineering . . . . . . . . . . . . . . . . . 175
Configuring the Bandwidth Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
Configuring Traffic Engineering Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
Requirements and Limitations for the Traffic Engineering Class
Matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
Configuring Class of Service for DiffServ-Aware Traffic Engineering . . . . . . . 178
Bandwidth Oversubscription Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
LSP Size Oversubscription . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Link Size Oversubscription . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Class Type Oversubscription and Local Oversubscription Multipliers . . . . . . . . . 180
Class Type Bandwidth and the LOM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
LOM Calculation for the MAM and Extended MAM Bandwidth Models . . . . . . . . 181
LOM Calculation for the Russian Dolls Bandwidth Model . . . . . . . . . . . . . . . . . . 182
Example: LOM Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
Configuring the Bandwidth Subscription Percentage for LSPs . . . . . . . . . . . . . . 183
Constraints on Configuring Bandwidth Subscription . . . . . . . . . . . . . . . . . . . 184
Configuring LSPs for DiffServ-Aware Traffic Engineering . . . . . . . . . . . . . . . . . . . 185
Configuring Class of Service for the Interfaces . . . . . . . . . . . . . . . . . . . . . . . 186
Configuring IGP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
Configuring Traffic-Engineered LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
Configuring Policing for LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
Configuring Fast Reroute for Traffic-Engineered LSPs . . . . . . . . . . . . . . . . . . 187
Configuring Multiclass LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
Configuring Class of Service for the Interfaces . . . . . . . . . . . . . . . . . . . . . . . 188
Configuring the IGP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
Configuring Class-Type Bandwidth Constraints for Multiclass LSPs . . . . . . 189
Configuring Policing for Multiclass LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190
Configuring Fast Reroute for Multiclass LSPs . . . . . . . . . . . . . . . . . . . . . . . . 190
Chapter 7
Static and Explicit-Path LSP Configuration Guidelines . . . . . . . . . . . . . . . . 193
Configuring Static LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
Configuring the Ingress Router for Static LSPs . . . . . . . . . . . . . . . . . . . . . . . . 193
Example: Configuring the Ingress Router . . . . . . . . . . . . . . . . . . . . . . . . 195
Configuring the Intermediate (Transit) and Egress Routers for Static
LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
Example: Configuring an Intermediate Router . . . . . . . . . . . . . . . . . . . . 197
Example: Configuring an Egress Router . . . . . . . . . . . . . . . . . . . . . . . . . 198
Configuring a Bypass LSP for the Static LSP . . . . . . . . . . . . . . . . . . . . . . . . . 199
Configuring the Protection Revert Timer for Static LSPs . . . . . . . . . . . . . . . . 199
Configuring Static Unicast Routes for Point-to-Multipoint LSPs . . . . . . . . . 199
Configuring Explicit-Path LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
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Chapter 8
Point-to-Multipoint LSP Configuration Guidelines . . . . . . . . . . . . . . . . . . . 203
Configuring Primary and Branch LSPs for Point-to-Multipoint LSPs . . . . . . . . . . 203
Configuring the Primary Point-to-Multipoint LSP . . . . . . . . . . . . . . . . . . . . . 204
Configuring a Branch LSP for Point-to-Multipoint LSPs . . . . . . . . . . . . . . . . 204
Configuring the Branch LSP as a Dynamic Path . . . . . . . . . . . . . . . . . . 205
Configuring the Branch LSP as a Static Path . . . . . . . . . . . . . . . . . . . . . 205
Configuring Link Protection for Point-to-Multipoint LSPs . . . . . . . . . . . . . . . . . . 205
Configuring Graceful Restart for Point-to-Multipoint LSPs . . . . . . . . . . . . . . . . . 206
Configuring a Multicast RPF Check Policy for Point-to-Multipoint LSPs . . . . . . . 206
Example: Configuring Multicast RPF Check Policy for a Point-to-Multipoint
LSP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207
Configuring Ingress PE Router Redundancy for Point-to-Multipoint LSPs . . . . . 207
Enabling Point-to-Point LSPs to Monitor Egress PE Routers . . . . . . . . . . . . . . . 208
Preserving Point-to-Multipoint LSP Functioning with Different Junos OS
Releases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
Example: Configuring a Point-to-Multipoint LSP . . . . . . . . . . . . . . . . . . . . . . . . . 209
Configuring Inter-domain P2MP LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
Chapter 9
Miscellaneous MPLS Properties Configuration Guidelines . . . . . . . . . . . . . 213
Configuring the Maximum Number of MPLS Labels . . . . . . . . . . . . . . . . . . . . . . . 213
Configuring MPLS to Pop the Label on the Ultimate-Hop Router . . . . . . . . . . . . 215
Advertising Explicit Null Labels to BGP Peers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
Configuring Traffic Engineering for LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
Using LSPs for Both BGP and IGP Traffic Forwarding . . . . . . . . . . . . . . . . . . 217
Using LSPs for Forwarding in Virtual Private Networks . . . . . . . . . . . . . . . . . 217
Using RSVP and LDP Routes for Forwarding but Not Route Selection . . . . . 217
Advertising the LSP Metric in Summary LSAs . . . . . . . . . . . . . . . . . . . . . . . . 218
Enabling Interarea Traffic Engineering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219
Enabling Inter-AS Traffic Engineering for LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . 219
Inter-AS Traffic Engineering Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . 220
Inter-AS Traffic Engineering Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
Configuring OSPF Passive TE Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221
Configuring MPLS to Gather Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222
Configuring System Log Messages and SNMP Traps for LSPs . . . . . . . . . . . . . . . 223
Configuring MPLS Firewall Filters and Policers . . . . . . . . . . . . . . . . . . . . . . . . . . . 224
Configuring MPLS Firewall Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
Examples: Configuring MPLS Firewall Filters . . . . . . . . . . . . . . . . . . . . . . . . . 226
Configuring Policers for LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226
LSP Policer Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227
Example: Configuring an LSP Policer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228
Configuring Automatic Policers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228
Configuring Automatic Policers for LSPs . . . . . . . . . . . . . . . . . . . . . . . . 229
Configuring Automatic Policers for DiffServ-Aware Traffic Engineering
LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230
Configuring Automatic Policers for Point-to-Multipoint LSPs . . . . . . . . 230
Disabling Automatic Policing on an LSP . . . . . . . . . . . . . . . . . . . . . . . . . 231
Example: Configuring Automatic Policing for an LSP . . . . . . . . . . . . . . . 231
Writing Different DSCP and EXP Values in MPLS-Tagged IP Packets . . . . . 232
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Configuring MPLS Rewrite Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
Rewriting the EXP Bits of All Three Labels of an Outgoing Packet . . . . . . . . 232
Rewriting MPLS and IPv4 Packet Headers . . . . . . . . . . . . . . . . . . . . . . . . . . . 233
Configuring BFD for MPLS IPv4 LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233
Configuring BFD for RSVP-Signaled LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . 234
Configuring a Failure Action for the BFD Session on an RSVP LSP . . . . . . . . 235
Pinging LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
Pinging MPLS LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
Pinging Point-to-Multipoint LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
Pinging the Endpoint Address of MPLS LSPs . . . . . . . . . . . . . . . . . . . . . . . . . 237
Pinging CCC LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
Pinging Layer 3 VPNs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
Support for LSP Ping and Traceroute Commands Based on RFC 4379 . . . . 237
Tracing MPLS and LSP Packets and Operations . . . . . . . . . . . . . . . . . . . . . . . . . . 237
Chapter 10
Summary of MPLS Configuration Statements . . . . . . . . . . . . . . . . . . . . . . . 239
adaptive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
adjust-interval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240
adjust-threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240
adjust-threshold-overflow-limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
admin-down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
admin-group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
admin-group (for Interfaces) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
admin-group (for LSPs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243
admin-groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244
admin-group-extended . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
admin-groups-extended . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246
admin-groups-extended-range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
advertisement-hold-time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
allow-fragmentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
always-mark-connection-protection-tlv . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
associate-backup-pe-groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
auto-bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250
auto-policing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
backup-pe-group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252
bandwidth (Fast Reroute, Signaled, and Multiclass LSPs) . . . . . . . . . . . . . . . . . 253
bandwidth (Static LSP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254
bandwidth-model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255
bandwidth-percent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256
bfd-liveness-detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
bypass (Static LSP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258
class-of-service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
diffserv-te . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
encoding-type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
exclude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
exclude (for Administrative Groups) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
exclude (for Fast Reroute) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264
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exclude-srlg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
expand-loose-hop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
explicit-null . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
failure-action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
family mpls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268
fast-reroute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269
fate-sharing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
from . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
gpid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
hop-limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
icmp-tunneling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274
include-all . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
include-all (for Administrative Groups) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
include-all (for Fast Reroute) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
include-any . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
include-any (for Administrative Groups) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
include-any (for Fast Reroute) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
ingress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279
install . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280
interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281
ipv6-tunneling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281
label-switched-path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282
ldp-tunneling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
least-fill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
link-protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285
link-protection (Dynamic LSPs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285
link-protection (Static LSPs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286
log-updown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
lsp-attributes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
maximum-bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
maximum-labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289
metric . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289
minimum-bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
monitor-bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
most-fill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
mpls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291
mtu-signaling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291
next-hop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292
no-cspf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
no-decrement-ttl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294
no-exclude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294
no-include-all . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294
no-include-any . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294
no-mcast-replication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295
no-install-to-address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295
node-protection (Static LSP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
no-propagate-ttl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297
no-record . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297
no-trap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298
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node-protection (Static LSP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
oam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300
optimize-aggressive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301
optimize-timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302
p2mp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303
p2mp-lsp-next-hop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303
path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304
path-mtu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305
policing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305
pop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306
preference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307
primary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
priority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309
protection-revert-time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310
push . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311
random . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312
record . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313
retry-limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313
retry-timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314
revert-timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315
rpf-check-policy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316
rsvp-error-hold-time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317
secondary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318
select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319
signal-bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319
smart-optimize-timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320
soft-preemption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321
srlg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321
srlg-cost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
srlg-value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
standby . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
static-label-switched-path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324
statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326
swap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
switch-away-lsps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328
switching-type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
te-class-matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
to . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331
traceoptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
traffic-engineering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334
Part 3
RSVP
Chapter 11
RSVP Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
RSVP Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 338
Supported RSVP Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 338
Junos OS RSVP Protocol Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340
RSVP Operation Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340
RSVP Authentication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341
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RSVP and IGP Hello Packets and Timers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341
RSVP Message Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341
Path Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342
Resv Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342
PathTear Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342
ResvTear Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342
PathErr Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343
ResvErr Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343
ResvConfirm Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343
RSVP Reservation Styles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343
RSVP Refresh Reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344
MTU Signaling in RSVP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345
How the Correct MTU Is Signaled in RSVP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346
Determining an Outgoing MTU Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346
MTU Signaling in RSVP Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347
Fast Reroute, Node Protection, and Link Protection . . . . . . . . . . . . . . . . . . . . . . . 347
Link Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348
Multiple Bypass LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
Node Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
RSVP Graceful Restart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
RSVP Graceful Restart Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351
RSVP Graceful Restart Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351
RSVP Graceful Restart Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351
Processing the Restart Cap Object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352
Chapter 12
RSVP Configuration Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
Minimum RSVP Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
Configuring RSVP and MPLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356
Example: Configuring RSVP and MPLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357
Configuring RSVP Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357
Configuring RSVP Refresh Reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357
Determining the Refresh Reduction Capability of RSVP Neighbors . . . 359
Configuring the RSVP Hello Interval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360
Configuring RSVP Authentication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360
Configuring the Bandwidth Subscription for Class Types . . . . . . . . . . . . . . . 361
Configuring the RSVP Update Threshold on an Interface . . . . . . . . . . . . . . . 361
Configuring RSVP for Unnumbered Interfaces . . . . . . . . . . . . . . . . . . . . . . . 362
Configuring RSVP Node ID Hellos . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 363
Configuring Hello Acknowledgments for Nonsession RSVP Neighbors . . . . . . . 363
Configuring Node Protection or Link Protection for LSPs . . . . . . . . . . . . . . . . . . . 364
Switching LSPs Away from a Network Node . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365
Configuring Inter-AS Node and Link Protection . . . . . . . . . . . . . . . . . . . . . . . . . . 366
Configuring Link Protection on Interfaces Used by LSPs . . . . . . . . . . . . . . . . . . . 366
Configuring Bypass LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367
Configuring the Next-Hop or Next-Next-Hop Node Address for Bypass
LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 368
Configuring Administrative Groups for Bypass LSPs . . . . . . . . . . . . . . . . . . . 368
Configuring the Bandwidth for Bypass LSPs . . . . . . . . . . . . . . . . . . . . . . . . . 369
Configuring Class of Service for Bypass LSPs . . . . . . . . . . . . . . . . . . . . . . . . 369
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Configuring the Hop Limit for Bypass LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . 370
Configuring the Maximum Number of Bypass LSPs . . . . . . . . . . . . . . . . . . . 370
Disabling CSPF for Bypass LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371
Disabling Node Protection for Bypass LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . 371
Configuring the Optimization Interval for Bypass LSPs . . . . . . . . . . . . . . . . . 371
Configuring an Explicit Path for Bypass LSPs . . . . . . . . . . . . . . . . . . . . . . . . . 372
Configuring the Amount of Bandwidth Subscribed for Bypass LSPs . . . . . . 373
Configuring Priority and Preemption for Bypass LSPs . . . . . . . . . . . . . . . . . . 373
Configuring RSVP Setup Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 374
Configuring RSVP Graceful Restart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 374
Enabling Graceful Restart for All Routing Protocols . . . . . . . . . . . . . . . . . . . 375
Disabling Graceful Restart for RSVP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375
Disabling RSVP Helper Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375
Configuring the Maximum Helper Recovery Time . . . . . . . . . . . . . . . . . . . . . 375
Configuring the Maximum Helper Restart Time . . . . . . . . . . . . . . . . . . . . . . 376
Configuring Load Balancing Across RSVP LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . 376
Configuring RSVP Automatic Mesh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 377
Configuring Timers for RSVP Refresh Messages . . . . . . . . . . . . . . . . . . . . . . . . . . 378
Preempting RSVP Sessions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 379
Configuring MTU Signaling in RSVP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 380
Enabling MTU Signaling in RSVP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 380
Enabling Packet Fragmentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 381
Configuring RSVP to Pop the Label on the Ultimate-Hop Router . . . . . . . . . . . . 381
Disabling Adjacency Down and Neighbor Down Notification in IS-IS and
OSPF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 382
Enabling Ultimate-Hop Popping on Point-to-Multipoint LSPs . . . . . . . . . . . . . . 382
Tracing RSVP Protocol Traffic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383
Examples: Tracing RSVP Protocol Traffic . . . . . . . . . . . . . . . . . . . . . . . . . . . 384
Chapter 13
Summary of RSVP Configuration Statements . . . . . . . . . . . . . . . . . . . . . . . 387
admin-group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387
aggregate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 388
authentication-key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 389
bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 390
bypass (Signaled LSP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 391
bypass (Static LSP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 392
class-of-service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 393
disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 394
fast-reroute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 395
graceful-deletion-timeout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 395
graceful-restart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 396
hello-acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397
hello-interval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397
hop-limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398
interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399
keep-multiplier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400
link-protection (RSVP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 401
load-balance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 402
max-bypasses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 403
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no-local-reversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 404
node-hello . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405
no-adjacency-down-notification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405
no-aggregate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405
no-cspf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 406
no-interface-hello . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 406
no-neighbor-down-notification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 407
no-node-id-subobject . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 407
no-p2mp-sublsp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408
no-reliable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408
node-link-protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408
optimize-timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 409
path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 410
peer-interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411
preemption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 412
priority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
refresh-time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414
reliable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414
rsvp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415
rsvp-te . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 416
setup-protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 417
soft-preemption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 417
subscription . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 418
traceoptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 419
transit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 421
tunnel-services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 422
update-threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 422
Part 4
LDP
Chapter 14
LDP Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425
LDP Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425
Supported LDP Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 426
Junos OS LDP Protocol Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 426
LDP Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 427
Tunneling LDP LSPs in RSVP LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 427
Tunneling LDP LSPs in RSVP LSPs Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . 427
Label Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
LDP Message Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 429
Discovery Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 429
Session Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 430
Advertisement Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 430
Notification Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 430
LDP Session Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 430
LDP Graceful Restart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431
Chapter 15
LDP Configuration Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433
Minimum LDP Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434
Enabling and Disabling LDP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434
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Configuring the LDP Timer for Hello Messages . . . . . . . . . . . . . . . . . . . . . . . . . . 434
Configuring the LDP Timer for Link Hello Messages . . . . . . . . . . . . . . . . . . . 435
Configuring the LDP Timer for Targeted Hello Messages . . . . . . . . . . . . . . . 435
Configuring the Delay Before LDP Neighbors Are Considered Down . . . . . . . . . . 435
Configuring the LDP Hold Time for Link Hello Messages . . . . . . . . . . . . . . . 436
Configuring the LDP Hold Time for Targeted Hello Messages . . . . . . . . . . . 436
Enabling Strict Targeted Hello Messages for LDP . . . . . . . . . . . . . . . . . . . . . . . . . 437
Configuring the Interval for LDP Keepalive Messages . . . . . . . . . . . . . . . . . . . . . . 437
Configuring the LDP Keepalive Timeout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 437
Configuring LDP Route Preferences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 438
Configuring LDP Graceful Restart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 438
Enabling Graceful Restart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 438
Disabling LDP Graceful Restart or Helper Mode . . . . . . . . . . . . . . . . . . . . . . 439
Configuring Reconnect Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 439
Configuring Recovery Time and Maximum Recovery Time . . . . . . . . . . . . . 440
Filtering Inbound LDP Label Bindings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 440
Examples: Filtering Inbound LDP Label Bindings . . . . . . . . . . . . . . . . . . . . . 442
Filtering Outbound LDP Label Bindings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 442
Examples: Filtering Outbound LDP Label Bindings . . . . . . . . . . . . . . . . . . . . 443
Specifying the Transport Address Used by LDP . . . . . . . . . . . . . . . . . . . . . . . . . . 444
Configuring the Prefixes Advertised into LDP from the Routing Table . . . . . . . . 445
Example: Configuring the Prefixes Advertised into LDP . . . . . . . . . . . . . . . . 445
Configuring FEC Deaggregation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 446
Configuring Policers for LDP FECs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 446
Configuring LDP IPv4 FEC Filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447
Configuring BFD for LDP LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 448
Configuring ECMP-Aware BFD for LDP LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 450
Configuring a Failure Action for the BFD Session on an LDP LSP . . . . . . . . . . . . 450
Configuring the Holddown Interval for the BFD Session . . . . . . . . . . . . . . . . . . . . 451
Configuring OAM Ingress Policies for LDP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 451
Configuring LDP LSP Traceroute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 451
Collecting LDP Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 452
LDP Statistics Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 453
Disabling LDP Statistics on the Penultimate-Hop Router . . . . . . . . . . . . . . 454
LDP Statistics Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 454
Tracing LDP Protocol Traffic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 455
Tracing LDP Protocol Traffic at the Protocol and Routing Instance
Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 455
Tracing LDP Protocol Traffic Within FECs . . . . . . . . . . . . . . . . . . . . . . . . . . . 456
Examples: Tracing LDP Protocol Traffic . . . . . . . . . . . . . . . . . . . . . . . . . . . . 456
Configuring Miscellaneous LDP Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 457
Configuring LDP to Use the IGP Route Metric . . . . . . . . . . . . . . . . . . . . . . . . 458
Preventing Addition of Ingress Routes to the inet.0 Routing Table . . . . . . . 458
Multiple-Instance LDP and Carrier-of-Carriers VPNs . . . . . . . . . . . . . . . . . . 458
Configuring MPLS and LDP to Pop the Label on the Ultimate-Hop
Router . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 458
Enabling LDP over RSVP-Established LSPs . . . . . . . . . . . . . . . . . . . . . . . . . 459
Enabling LDP over RSVP-Established LSPs in Heterogeneous Networks . . 459
Configuring the TCP MD5 Signature for LDP Sessions . . . . . . . . . . . . . . . . . 460
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Configuring LDP Session Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461
Disabling SNMP Traps for LDP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461
Configuring LDP Synchronization with the IGP on LDP Links . . . . . . . . . . . . 461
Configuring LDP Synchronization with the IGP on the Router . . . . . . . . . . . 462
Configuring the Label Withdrawal Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 462
Ignoring the LDP Subnet Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 463
Chapter 16
Summary of LDP Configuration Statements . . . . . . . . . . . . . . . . . . . . . . . . 465
allow-subnet-mismatch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465
authentication-key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 466
bfd-liveness-detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 467
deaggregate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 468
disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 469
ecmp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 470
egress-policy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 470
explicit-null . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 471
export . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 471
failure-action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 472
graceful-restart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 473
hello-interval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 474
helper-disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 475
holddown-interval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 475
hold-time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 476
ignore-lsp-metrics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 477
igp-synchronization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 477
import . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 478
ingress-policy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 478
interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 479
keepalive-interval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 480
keepalive-timeout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 480
l2-smart-policy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 481
label-withdrawal-delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 481
ldp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 482
ldp-synchronization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 483
log-updown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 483
maximum-neighbor-recovery-time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 484
no-deaggregate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 484
no-forwarding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 485
oam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 486
p2mp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 487
periodic-traceroute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 488
policing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 489
preference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 490
reconnect-time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 490
recovery-time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 491
session . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 491
session-protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 492
strict-targeted-hellos . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 492
targeted-hello . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 493
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traceoptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 494
track-igp-metric . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 496
traffic-statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 497
transport-address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 498
Part 5
CCC and TCC
Chapter 17
CCC and TCC Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 501
CCC Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 501
Transmitting Nonstandard BPDUs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 502
TCC Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 502
CCC and TCC Graceful Restart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 503
Chapter 18
CCC and TCC Configuration Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 505
Configuring Layer 2 Switching Cross-Connects Using CCC . . . . . . . . . . . . . . . . . 505
Configuring the CCC Encapsulation for Layer 2 Switching
Cross-Connects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 506
Configuring ATM Encapsulation for Layer 2 Switching
Cross-Connects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 506
Configuring Ethernet Encapsulation for Layer 2 Switching
Cross-Connects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 507
Configuring Ethernet VLAN Encapsulation for Layer 2 Switching
Cross-Connects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 507
Configuring Aggregated Ethernet Encapsulation for Layer 2 Switching
Cross-Connects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 508
Configuring Frame Relay Encapsulation for Layer 2 Switching
Cross-Connects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 509
Configuring PPP and Cisco HDLC Encapsulation for Layer 2 Switching
Cross-Connects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 510
Configuring the CCC Connection for Layer 2 Switching Cross-Connects . . . 510
Configuring MPLS for Layer 2 Switching Cross-Connects . . . . . . . . . . . . . . . . 511
Example: Configuring a Layer 2 Switching Cross-Connect . . . . . . . . . . . . . . . 511
Configuring MPLS LSP Tunnel Cross-Connects Using CCC . . . . . . . . . . . . . . . . . 513
Configuring the CCC Encapsulation for LSP Tunnel Cross-Connects . . . . . . 514
Configuring the CCC Connection for LSP Tunnel Cross-Connects . . . . . . . . 515
Example: Configuring an LSP Tunnel Cross-Connect . . . . . . . . . . . . . . . . . . 516
Configuring LSP Stitching Cross-Connects Using CCC . . . . . . . . . . . . . . . . . . . . . 517
Example: Configuring an LSP Stitching Cross-Connect . . . . . . . . . . . . . . . . . 518
Configuring TCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 518
Configuring the Encapsulation for Layer 2 Switching TCCs . . . . . . . . . . . . . . 519
Configuring PPP and Cisco HDLC Encapsulation for Layer 2 Switching
TCCs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 519
Configuring ATM Encapsulation for Layer 2 Switching TCCs . . . . . . . . . 520
Configuring Frame Relay Encapsulation for Layer 2 Switching TCCs . . 520
Configuring Ethernet Encapsulation for Layer 2 Switching TCCs . . . . . 520
Configuring Ethernet Extended VLAN Encapsulation for Layer 2
Switching TCCs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 521
Configuring ARP for Ethernet and Ethernet Extended VLAN
Encapsulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 522
Configuring the Connection for Layer 2 Switching TCCs . . . . . . . . . . . . . . . . 522
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Configuring MPLS for Layer 2 Switching TCCs . . . . . . . . . . . . . . . . . . . . . . . . 523
Configuring CCC and TCC Graceful Restart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 524
Configuring CCC Switching for Point-to-Multipoint LSPs . . . . . . . . . . . . . . . . . . 524
Configuring the Point-to-Multipoint LSP Switch on Ingress PE Routers . . . 524
Configuring the Point-to-Multipoint LSP Switch on Egress PE Routers . . . . 525
Chapter 19
Summary of CCC and TCC Configuration Statements . . . . . . . . . . . . . . . . . 527
connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 528
encapsulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 529
encapsulation (Logical Interface) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 530
encapsulation (Physical Interface) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 532
interface-switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 534
lsp-switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 535
p2mp-receive-switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 536
p2mp-transmit-switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 537
remote-interface-switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 538
Part 6
GMPLS
Chapter 20
GMPLS Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 541
Supported GMPLS Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 541
GMPLS Terms and Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 542
Introduction to GMPLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 543
GMPLS Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 544
GMPLS and OSPF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 545
GMPLS and CSPF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 545
GMPLS Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 546
Chapter 21
GMPLS Configuration Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 547
LMP Configuration Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 547
Configuring LMP Traffic Engineering Links . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 548
Configuring the Local IP Address for Traffic Engineering Links . . . . . . . . . . . 549
Configuring the Remote IP Address for Traffic Engineering Links . . . . . . . . . 549
Configuring the Remote ID for Traffic Engineering Links . . . . . . . . . . . . . . . . 550
Configuring LMP Peers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 550
Configuring the ID for LMP Peers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 551
Configuring the Interface for Control Channels Between LMP Peers . . . . . . 551
Configuring the LMP Control Channel Interface for the Peer . . . . . . . . . . . . . 551
Configuring the Remote IP Address for LMP Control Channels . . . . . . . . . . 552
Configuring Hello Message Intervals for LMP Control Channels . . . . . . . . . . 552
Controlling Message Exchange for LMP Control Channels . . . . . . . . . . . . . . 553
Preventing the Local Peer from Initiating LMP Negotiation . . . . . . . . . . . . . 554
Associating Traffic Engineering Links with LMP Peers . . . . . . . . . . . . . . . . . 554
Disabling the Traffic Engineering Link for LMP Peers . . . . . . . . . . . . . . . . . . 554
Configuring RSVP and OSPF for LMP Peer Interfaces . . . . . . . . . . . . . . . . . . . . . 555
Configuring RSVP Signaling for LMP Peer Interfaces . . . . . . . . . . . . . . . . . . 555
Configuring OSPF Routing for LMP Peer Interfaces . . . . . . . . . . . . . . . . . . . 555
Configuring the Hello Interval for LMP Peer Interfaces . . . . . . . . . . . . . . . . . 556
Configuring MPLS Paths for GMPLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 556
Tracing LMP Traffic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 557
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Configuring MPLS LSPs for GMPLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 557
Configuring the Encoding Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 558
Configuring the GPID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 558
Configuring the Signal Bandwidth Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . 559
Configuring GMPLS Bidirectional LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 559
Allowing Nonpacket GMPLS LSPs to Establish Paths Through Routers
Running the Junos OS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 559
Gracefully Tearing Down GMPLS LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 560
Temporarily Deleting GMPLS LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 560
Permanently Deleting GMPLS LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 560
Configuring the Graceful Deletion Timeout Interval . . . . . . . . . . . . . . . . . . . . 561
Chapter 22
Hierarchy of RSVP LSPs Configuration Guidelines . . . . . . . . . . . . . . . . . . . . 563
Hierarchy of RSVP LSPs Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 563
Hierarchy of RSVP LSPs Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 563
Hierarchy of RSVP LSPs Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 563
Hierarchy of RSVP LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 564
Advertising the Forwarding Adjacency with OSPF . . . . . . . . . . . . . . . . . . . . . . . . 564
Configuring a Hierarchy of RSVP LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 564
Configuring an RSVP LSP on Ingress Routers . . . . . . . . . . . . . . . . . . . . . . . . 565
Configuring Forwarding Adjacencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 565
Configuring the Local IP Address for Forwarding Adjacencies . . . . . . . 565
Configuring the Remote IP Address for Forwarding Adjacencies . . . . . 565
Configuring the LSP for Forwarding Adjacencies . . . . . . . . . . . . . . . . . . 566
Configuring RSVP for Forwarding Adjacencies . . . . . . . . . . . . . . . . . . . . . . . 566
Advertising Forwarding Adjacencies Using OSPF . . . . . . . . . . . . . . . . . . . . . 567
Chapter 23
Summary of GMPLS Configuration Statements . . . . . . . . . . . . . . . . . . . . . 569
address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 569
control-channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 570
dead-interval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 570
disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 571
disable (GMPLS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 571
disable (OSPF Peer Interface) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 571
hello-dead-interval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 572
hello-interval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 573
hello-interval (LMP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 573
hello-interval (OSPF) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 574
interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 574
label-switched-path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 575
link-management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 575
lmp-control-channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 576
lmp-protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 576
local-address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 577
passive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 577
peer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 578
peer-interface (OSPF) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 579
remote-address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 580
remote-address (for LMP Control Channel) . . . . . . . . . . . . . . . . . . . . . . . . . 580
remote-address (for LMP Traffic Engineering) . . . . . . . . . . . . . . . . . . . . . . . 580
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remote-id . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 581
retransmission-interval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 581
retransmit-interval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 582
retry-limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 582
te-link . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 583
traceoptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 584
transit-delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 586
Part 7
Indexes
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 589
Index of Statements and Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 609
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List of Figures
Part 2
MPLS
Chapter 3
MPLS Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Figure 1: Label Encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Figure 2: Class-of-Service Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Figure 3: CSPF Computation Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Figure 4: Aggregation Router A Dual-Homed on Core Routers B and C . . . . . . . . . 35
Figure 5: Typical SPF Tree, Sourced from Router A . . . . . . . . . . . . . . . . . . . . . . . . . 37
Figure 6: Modified SPF Tree, Using LSP A–D as a Shortcut . . . . . . . . . . . . . . . . . . 37
Figure 7: Modified SPF Tree, Using LSP A–D and LSP A–E as Shortcuts . . . . . . . . 38
Figure 8: IGP Shortcuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Figure 9: IGP Shortcuts in a Bigger Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Figure 10: SPF Computations with Advertised LSPs . . . . . . . . . . . . . . . . . . . . . . . . 41
Figure 11: MPLS Application Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Figure 12: How BGP Determines How to Reach Next-Hop Addresses . . . . . . . . . . 44
Figure 13: Routing and Forwarding Tables, traffic-engineering bgp . . . . . . . . . . . . 45
Figure 14: Routing and Forwarding Tables, traffic-engineering bgp-igp . . . . . . . . 46
Figure 15: Detours Established for an LSP Using Fast Reroute . . . . . . . . . . . . . . . . 48
Figure 16: Detour After the Link from Router B to Router C Fails . . . . . . . . . . . . . . 48
Figure 17: Detours Merging into Other Detours . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Figure 18: Point-to-Multipoint LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Chapter 4
MPLS Router Configuration Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Figure 19: IPv6 Networks Linked by MPLS IPv4 Tunnels . . . . . . . . . . . . . . . . . . . . . 67
Chapter 5
MPLS-Signaled LSP Configuration Guidelines . . . . . . . . . . . . . . . . . . . . . . . 125
Figure 20: least-fill Load Balancing Algorithm Example . . . . . . . . . . . . . . . . . . . . 163
Chapter 7
Static and Explicit-Path LSP Configuration Guidelines . . . . . . . . . . . . . . . . 193
Figure 21: Static MPLS Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
Part 3
RSVP
Chapter 11
RSVP Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
Figure 22: Link Protection Creating a Bypass LSP for the Protected Interface . . 348
Figure 23: Node Protection Creating a Next-Next-Hop Bypass LSP . . . . . . . . . . 350
Part 4
LDP
Chapter 14
LDP Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425
Figure 24: Swap and Push When LDP LSPs Are Tunneled Through RSVP
LSPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
Figure 25: Double Push When LDP LSPs Are Tunneled Through RSVP LSPs . . . 429
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
Part 5
CCC and TCC
Chapter 17
CCC and TCC Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 501
Figure 26: TCC Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 502
Figure 27: Remote Interface Switch Connecting Two CE Routers Using CCC . . . 503
Chapter 18
CCC and TCC Configuration Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 505
Figure 28: Layer 2 Switching Cross-Connect . . . . . . . . . . . . . . . . . . . . . . . . . . . . 505
Figure 29: Topology of a Frame Relay Layer 2 Switching Cross-Connect . . . . . . . 511
Figure 30: Sample Topology of a VLAN Layer 2 Switching Cross-Connect . . . . . 512
Figure 31: MPLS Tunnel Cross-Connect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 513
Figure 32: Example Topology of MPLS LSP Tunnel Cross-Connect . . . . . . . . . . . 516
Figure 33: LSP Stitching Cross-Connect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 517
Figure 34: Example Topology of LSP Stitching Cross-Connect . . . . . . . . . . . . . . 518
xxiv
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List of Tables
About This Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxvii
Table 1: Notice Icons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxi
Table 2: Text and Syntax Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxi
Part 2
MPLS
Chapter 5
MPLS-Signaled LSP Configuration Guidelines . . . . . . . . . . . . . . . . . . . . . . . 125
Table 3: MPLS LSP Load Balancing Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Table 4: MPLS CoS Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
Chapter 6
DiffServ-Aware Traffic Engineering Configuration Guidelines . . . . . . . . . . 169
Table 5: Default Values for the Traffic Engineering Class Matrix . . . . . . . . . . . . . . 177
Chapter 9
Miscellaneous MPLS Properties Configuration Guidelines . . . . . . . . . . . . . 213
Table 6: Sample Scenarios for Using 3, 4, or 5 MPLS Labels . . . . . . . . . . . . . . . . 214
Part 3
RSVP
Chapter 11
RSVP Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
Table 7: One-to-One Backup Compared with Facility Backup . . . . . . . . . . . . . . . 347
Chapter 12
RSVP Configuration Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
Table 8: RSVP Refresh Reduction Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358
Part 4
LDP
Chapter 15
LDP Configuration Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433
Table 9: from Operators That Apply to LDP Received-Label Filtering . . . . . . . . . 441
Table 10: to Operators for LDP Outbound-Label Filtering . . . . . . . . . . . . . . . . . . 443
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
xxvi
Copyright © 2011, Juniper Networks, Inc.
About This Guide
®
This preface provides the following guidelines for using the Junos OS MPLS Applications
Configuration Guide:
•
Junos OS Documentation and Release Notes on page xxvii
•
Objectives on page xxviii
•
Audience on page xxviii
•
Supported Platforms on page xxviii
•
Using the Indexes on page xxix
•
Using the Examples in This Manual on page xxix
•
Documentation Conventions on page xxx
•
Documentation Feedback on page xxxii
•
Requesting Technical Support on page xxxii
Junos OS Documentation and Release Notes
For a list of related Junos OS documentation, see
http://www.juniper.net/techpubs/software/junos/ .
If the information in the latest release notes differs from the information in the
documentation, follow the Junos OS Release Notes.
®
To obtain the most current version of all Juniper Networks technical documentation,
see the product documentation page on the Juniper Networks website at
http://www.juniper.net/techpubs/ .
Juniper Networks supports a technical book program to publish books by Juniper Networks
engineers and subject matter experts with book publishers around the world. These
books go beyond the technical documentation to explore the nuances of network
architecture, deployment, and administration using the Junos operating system (Junos
OS) and Juniper Networks devices. In addition, the Juniper Networks Technical Library,
published in conjunction with O'Reilly Media, explores improving network security,
reliability, and availability using Junos OS configuration techniques. All the books are for
sale at technical bookstores and book outlets around the world. The current list can be
viewed at http://www.juniper.net/books .
Copyright © 2011, Juniper Networks, Inc.
xxvii
Junos OS 11.4 MPLS Applications Configuration Guide
Objectives
This guide provides an overview of the MPLS applications functions of the Junos OS and
describes how to configure MPLS applications on the router.
NOTE: For additional information about the Junos OS—either corrections to
or information that might have been omitted from this guide—see the software
release notes at http://www.juniper.net/ .
Audience
This guide is designed for network administrators who are configuring and monitoring a
Juniper Networks M Series, MX Series, T Series, EX Series, or J Series router or switch.
To use this guide, you need a broad understanding of networks in general, the Internet
in particular, networking principles, and network configuration. You must also be familiar
with one or more of the following Internet routing protocols:
•
Border Gateway Protocol (BGP)
•
Distance Vector Multicast Routing Protocol (DVMRP)
•
Intermediate System-to-Intermediate System (IS-IS)
•
Internet Control Message Protocol (ICMP) router discovery
•
Internet Group Management Protocol (IGMP)
•
Multiprotocol Label Switching (MPLS)
•
Open Shortest Path First (OSPF)
•
Protocol-Independent Multicast (PIM)
•
Resource Reservation Protocol (RSVP)
•
Routing Information Protocol (RIP)
•
Simple Network Management Protocol (SNMP)
Personnel operating the equipment must be trained and competent; must not conduct
themselves in a careless, willfully negligent, or hostile manner; and must abide by the
instructions provided by the documentation.
Supported Platforms
For the features described in this manual, the Junos OS currently supports the following
platforms:
xxviii
•
J Series
•
M Series
Copyright © 2011, Juniper Networks, Inc.
About This Guide
•
MX Series
•
T Series
•
EX Series
Using the Indexes
This reference contains two indexes: a complete index that includes topic entries, and
an index of statements and commands only.
In the index of statements and commands, an entry refers to a statement summary
section only. In the complete index, the entry for a configuration statement or command
contains at least two parts:
•
The primary entry refers to the statement summary section.
•
The secondary entry, usage guidelines, refers to the section in a configuration guidelines
chapter that describes how to use the statement or command.
Using the Examples in This Manual
If you want to use the examples in this manual, you can use the load merge or the load
merge relative command. These commands cause the software to merge the incoming
configuration into the current candidate configuration. The example does not become
active until you commit the candidate configuration.
If the example configuration contains the top level of the hierarchy (or multiple
hierarchies), the example is a full example. In this case, use the load merge command.
If the example configuration does not start at the top level of the hierarchy, the example
is a snippet. In this case, use the load merge relative command. These procedures are
described in the following sections.
Merging a Full Example
To merge a full example, follow these steps:
1.
From the HTML or PDF version of the manual, copy a configuration example into a
text file, save the file with a name, and copy the file to a directory on your routing
platform.
For example, copy the following configuration to a file and name the file ex-script.conf.
Copy the ex-script.conf file to the /var/tmp directory on your routing platform.
system {
scripts {
commit {
file ex-script.xsl;
}
}
}
interfaces {
fxp0 {
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
disable;
unit 0 {
family inet {
address 10.0.0.1/24;
}
}
}
}
2. Merge the contents of the file into your routing platform configuration by issuing the
load merge configuration mode command:
[edit]
user@host# load merge /var/tmp/ex-script.conf
load complete
Merging a Snippet
To merge a snippet, follow these steps:
1.
From the HTML or PDF version of the manual, copy a configuration snippet into a text
file, save the file with a name, and copy the file to a directory on your routing platform.
For example, copy the following snippet to a file and name the file
ex-script-snippet.conf. Copy the ex-script-snippet.conf file to the /var/tmp directory
on your routing platform.
commit {
file ex-script-snippet.xsl; }
2. Move to the hierarchy level that is relevant for this snippet by issuing the following
configuration mode command:
[edit]
user@host# edit system scripts
[edit system scripts]
3. Merge the contents of the file into your routing platform configuration by issuing the
load merge relative configuration mode command:
[edit system scripts]
user@host# load merge relative /var/tmp/ex-script-snippet.conf
load complete
For more information about the load command, see the Junos OS CLI User Guide.
Documentation Conventions
Table 1 on page xxxi defines notice icons used in this guide.
xxx
Copyright © 2011, Juniper Networks, Inc.
About This Guide
Table 1: Notice Icons
Icon
Meaning
Description
Informational note
Indicates important features or instructions.
Caution
Indicates a situation that might result in loss of data or hardware damage.
Warning
Alerts you to the risk of personal injury or death.
Laser warning
Alerts you to the risk of personal injury from a laser.
Table 2 on page xxxi defines the text and syntax conventions used in this guide.
Table 2: Text and Syntax Conventions
Convention
Description
Examples
Bold text like this
Represents text that you type.
To enter configuration mode, type the
configure command:
user@host> configure
Fixed-width text like this
Italic text like this
Italic text like this
Text like this
< > (angle brackets)
Copyright © 2011, Juniper Networks, Inc.
Represents output that appears on the
terminal screen.
user@host> show chassis alarms
•
Introduces important new terms.
•
•
Identifies book names.
•
Identifies RFC and Internet draft titles.
A policy term is a named structure
that defines match conditions and
actions.
•
Junos OS System Basics Configuration
Guide
•
RFC 1997, BGP Communities Attribute
No alarms currently active
Represents variables (options for which
you substitute a value) in commands or
configuration statements.
Configure the machine’s domain name:
Represents names of configuration
statements, commands, files, and
directories; interface names;
configuration hierarchy levels; or labels
on routing platform components.
•
To configure a stub area, include the
stub statement at the [edit protocols
ospf area area-id] hierarchy level.
•
The console port is labeled CONSOLE.
Enclose optional keywords or variables.
stub <default-metric metric>;
[edit]
root@# set system domain-name
domain-name
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Junos OS 11.4 MPLS Applications Configuration Guide
Table 2: Text and Syntax Conventions (continued)
Convention
Description
Examples
| (pipe symbol)
Indicates a choice between the mutually
exclusive keywords or variables on either
side of the symbol. The set of choices is
often enclosed in parentheses for clarity.
broadcast | multicast
# (pound sign)
Indicates a comment specified on the
same line as the configuration statement
to which it applies.
rsvp { # Required for dynamic MPLS only
[ ] (square brackets)
Enclose a variable for which you can
substitute one or more values.
community name members [
community-ids ]
Indention and braces ( { } )
Identify a level in the configuration
hierarchy.
; (semicolon)
Identifies a leaf statement at a
configuration hierarchy level.
(string1 | string2 | string3)
[edit]
routing-options {
static {
route default {
nexthop address;
retain;
}
}
}
J-Web GUI Conventions
Bold text like this
Represents J-Web graphical user
interface (GUI) items you click or select.
> (bold right angle bracket)
Separates levels in a hierarchy of J-Web
selections.
•
In the Logical Interfaces box, select
All Interfaces.
•
To cancel the configuration, click
Cancel.
In the configuration editor hierarchy,
select Protocols>Ospf.
Documentation Feedback
We encourage you to provide feedback, comments, and suggestions so that we can
improve the documentation. You can send your comments to
techpubs-comments@juniper.net, or fill out the documentation feedback form at
https://www.juniper.net/cgi-bin/docbugreport/ . If you are using e-mail, be sure to include
the following information with your comments:
•
Document or topic name
•
URL or page number
•
Software release version (if applicable)
Requesting Technical Support
Technical product support is available through the Juniper Networks Technical Assistance
Center (JTAC). If you are a customer with an active J-Care or JNASC support contract,
xxxii
Copyright © 2011, Juniper Networks, Inc.
About This Guide
or are covered under warranty, and need postsales technical support, you can access
our tools and resources online or open a case with JTAC.
•
JTAC policies—For a complete understanding of our JTAC procedures and policies,
review the JTAC User Guide located at
http://www.juniper.net/us/en/local/pdf/resource-guides/7100059-en.pdf .
•
JTAC Hours of Operation —The JTAC centers have resources available 24 hours a day,
7 days a week, 365 days a year.
Self-Help Online Tools and Resources
For quick and easy problem resolution, Juniper Networks has designed an online
self-service portal called the Customer Support Center (CSC) that provides you with the
following features:
•
Find CSC offerings: http://www.juniper.net/customers/support/
•
Find product documentation: http://www.juniper.net/techpubs/
•
Find solutions and answer questions using our Knowledge Base: http://kb.juniper.net/
•
Download the latest versions of software and review release notes:
http://www.juniper.net/customers/csc/software/
•
Search technical bulletins for relevant hardware and software notifications:
https://www.juniper.net/alerts/
•
Join and participate in the Juniper Networks Community Forum:
http://www.juniper.net/company/communities/
•
Open a case online in the CSC Case Management tool: http://www.juniper.net/cm/
To verify service entitlement by product serial number, use our Serial Number Entitlement
(SNE) Tool: https://tools.juniper.net/SerialNumberEntitlementSearch/
Opening a Case with JTAC
You can open a case with JTAC on the Web or by telephone.
•
Use the Case Management tool in the CSC at http://www.juniper.net/cm/ .
•
Call 1-888-314-JTAC (1-888-314-5822 toll-free in the USA, Canada, and Mexico).
For international or direct-dial options in countries without toll-free numbers, visit us at
http://www.juniper.net/support/requesting-support.html
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
xxxiv
Copyright © 2011, Juniper Networks, Inc.
PART 1
Overview
•
Traffic Engineering Overview on page 3
•
Complete MPLS Applications Configuration Statements on page 9
Copyright © 2011, Juniper Networks, Inc.
1
Junos OS 11.4 MPLS Applications Configuration Guide
2
Copyright © 2011, Juniper Networks, Inc.
CHAPTER 1
Traffic Engineering Overview
This chapter discusses the following topics:
•
Traffic Engineering Capabilities on page 3
•
Components of Traffic Engineering on page 4
•
Packet Forwarding Component on page 4
•
Packet Forwarding Based on Label Swapping on page 4
•
How a Packet Traverses an MPLS Backbone on page 5
•
Information Distribution Component on page 5
•
Path Selection Component on page 6
•
Offline Planning and Analysis on page 6
•
Signaling Component on page 7
•
Flexible LSP Calculation and Configuration on page 7
Traffic Engineering Capabilities
The task of mapping traffic flows onto an existing physical topology is called traffic
engineering. Traffic engineering provides the ability to move traffic flow away from the
shortest path selected by the interior gateway protocol (IGP) and onto a potentially less
congested physical path across a network.
Traffic engineering provides the capabilities to do the following:
•
Route primary paths around known bottlenecks or points of congestion in the network.
•
Provide precise control over how traffic is rerouted when the primary path is faced with
single or multiple failures.
•
Provide more efficient use of available aggregate bandwidth and long-haul fiber by
ensuring that subsets of the network do not become overutilized while other subsets
of the network along potential alternate paths are underutilized.
•
Maximize operational efficiency.
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
•
Enhance the traffic-oriented performance characteristics of the network by minimizing
packet loss, minimizing prolonged periods of congestion, and maximizing throughput.
•
Enhance statistically bound performance characteristics of the network (such as loss
ratio, delay variation, and transfer delay) required to support a multiservices Internet.
Components of Traffic Engineering
In the Junos OS, traffic engineering is implemented with MPLS and RSVP. Traffic
engineering is composed of four functional components:
•
Packet Forwarding Component on page 4
•
Information Distribution Component on page 5
•
Path Selection Component on page 6
•
Signaling Component on page 7
Packet Forwarding Component
The packet forwarding component of the Junos traffic engineering architecture is MPLS,
which is responsible for directing a flow of IP packets along a predetermined path across
a network. This path is called a label-switched path (LSP). LSPs are simplex; that is, the
traffic flows in one direction from the head-end (ingress) router to a tail-end (egress)
router. Duplex traffic requires two LSPs: one LSP to carry traffic in each direction. An LSP
is created by the concatenation of one or more label-switched hops, allowing a packet
to be forwarded from one router to another across the MPLS domain.
When an ingress router receives an IP packet, it adds an MPLS header to the packet and
forwards it to the next router in the LSP. The labeled packet is forwarded along the LSP
by each router until it reaches the tail end of the LSP, the egress router. At this point the
MPLS header is removed, and the packet is forwarded based on Layer 3 information such
as the IP destination address. The value of this scheme is that the physical path of the
LSP is not limited to what the IGP would choose as the shortest path to reach the
destination IP address.
This section discusses the following topics:
•
Packet Forwarding Based on Label Swapping on page 4
•
How a Packet Traverses an MPLS Backbone on page 5
Packet Forwarding Based on Label Swapping
The packet forwarding process at each router is based on the concept of label swapping.
This concept is similar to what occurs at each Asynchronous Transfer Mode (ATM) switch
in a permanent virtual circuit (PVC). Each MPLS packet carries a 4-byte encapsulation
header that contains a 20-bit, fixed-length label field. When a packet containing a label
arrives at a router, the router examines the label and copies it as an index to its MPLS
forwarding table. Each entry in the forwarding table contains an interface-inbound label
4
Copyright © 2011, Juniper Networks, Inc.
Chapter 1: Traffic Engineering Overview
pair mapped to a set of forwarding information that is applied to all packets arriving on
the specific interface with the same inbound label.
How a Packet Traverses an MPLS Backbone
This section describes how an IP packet is processed as it traverses an MPLS backbone
network.
At the entry edge of the MPLS backbone, the IP header is examined by the ingress router.
Based on this analysis, the packet is classified, assigned a label, encapsulated in an MPLS
header, and forwarded toward the next hop in the LSP. MPLS provides a high degree of
flexibility in the way that an IP packet can be assigned to an LSP. For example, in the
Junos traffic engineering implementation, all packets arriving at the ingress router that
are destined to exit the MPLS domain at the same egress router are forwarded along the
same LSP.
Once the packet begins to traverse the LSP, each router uses the label to make the
forwarding decision. The MPLS forwarding decision is made independently of the original
IP header: the incoming interface and label are used as lookup keys into the MPLS
forwarding table. The old label is replaced with a new label, and the packet is forwarded
to the next hop along the LSP. This process is repeated at each router in the LSP until
the packet reaches the egress router.
When the packet arrives at the egress router, the label is removed and the packet exits
the MPLS domain. The packet is then forwarded based on the destination IP address
contained in the packet’s original IP header according to the traditional shortest path
calculated by the IP routing protocol.
Information Distribution Component
Traffic engineering requires detailed knowledge about the network topology as well as
dynamic information about network loading. To implement the information distribution
component, simple extensions to the IGPs are defined. Link attributes are included as
part of each router’s link-state advertisement. IS-IS extensions include the definition of
new type length values (TLVs), whereas OSPF extensions are implemented with opaque
link-state advertisements (LSAs). The standard flooding algorithm used by the link-state
IGPs ensures that link attributes are distributed to all routers in the routing domain. Some
of the traffic engineering extensions to be added to the IGP link-state advertisement
include maximum link bandwidth, maximum reserved link bandwidth, current bandwidth
reservation, and link coloring.
Each router maintains network link attributes and topology information in a specialized
traffic engineering database. The traffic engineering database is used exclusively for
calculating explicit paths for the placement of LSPs across the physical topology. A
separate database is maintained so that the subsequent traffic engineering computation
is independent of the IGP and the IGP’s link-state database. Meanwhile, the IGP continues
its operation without modification, performing the traditional shortest-path calculation
based on information contained in the router’s link-state database.
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
Path Selection Component
After network link attributes and topology information are flooded by the IGP and placed
in the traffic engineering database, each ingress router uses the traffic engineering
database to calculate the paths for its own set of LSPs across the routing domain. The
path for each LSP can be represented by either a strict or loose explicit route. An explicit
route is a preconfigured sequence of routers that should be part of the physical path of
the LSP. If the ingress router specifies all the routers in the LSP, the LSP is said to be
identified by a strict explicit route. If the ingress router specifies only some of the routers
in the LSP, the LSP is described as a loose explicit route. Support for strict and loose
explicit routes allows the path selection process to be given broad latitude whenever
possible, but to be constrained when necessary.
The ingress router determines the physical path for each LSP by applying a Constrained
Shortest Path First (CSPF) algorithm to the information in the traffic engineering database.
CSPF is a shortest-path-first algorithm that has been modified to take into account
specific restrictions when the shortest path across the network is calculated. Input into
the CSPF algorithm includes:
•
Topology link-state information learned from the IGP and maintained in the traffic
engineering database
•
Attributes associated with the state of network resources (such as total link bandwidth,
reserved link bandwidth, available link bandwidth, and link color) that are carried by
IGP extensions and stored in the traffic engineering database
•
Administrative attributes required to support traffic traversing the proposed LSP (such
as bandwidth requirements, maximum hop count, and administrative policy
requirements) that are obtained from user configuration
As CSPF considers each candidate node and link for a new LSP, it either accepts or rejects
a specific path component based on resource availability or whether selecting the
component violates user policy constraints. The output of the CSPF calculation is an
explicit route consisting of a sequence of router addresses that provides the shortest
path through the network that meets the constraints. This explicit route is then passed
to the signaling component, which establishes the forwarding state in the routers along
the LSP.
Offline Planning and Analysis
Despite the reduced management effort resulting from online path calculation, an offline
planning and analysis tool is still required to optimize traffic engineering globally. Online
calculation takes resource constraints into account and calculates one LSP at a time.
The challenge with this approach is that it is not deterministic. The order in which LSPs
are calculated plays a critical role in determining each LSP’s physical path across the
network. LSPs that are calculated early in the process have more resources available to
them than LSPs calculated later in the process because previously calculated LSPs
consume network resources. If the order in which the LSPs are calculated is changed,
the resulting set of physical paths for the LSPs also can change.
6
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Chapter 1: Traffic Engineering Overview
An offline planning and analysis tool simultaneously examines each link’s resource
constraints and the requirements of each LSP. Although the offline approach can take
several hours to complete, it performs global calculations, compares the results of each
calculation, and then selects the best solution for the network as a whole. The output of
the offline calculation is a set of LSPs that optimizes utilization of network resources.
After the offline calculation is completed, the LSPs can be established in any order
because each is installed according to the rules for the globally optimized solution.
Signaling Component
An LSP is not known to be workable until it is actually established by the signaling
component. The signaling component, which is responsible for establishing LSP state
and distributing labels, relies on a number of extensions to RSVP:
•
The Explicit Route object allows an RSVP path message to traverse an explicit sequence
of routers that is independent of conventional shortest-path IP routing. The explicit
route can be either strict or loose.
•
The Label Request object permits the RSVP path message to request that intermediate
routers provide a label binding for the LSP that it is establishing.
•
The Label object allows RSVP to support the distribution of labels without changing
its existing mechanisms. Because the RSVP Resv message follows the reverse path
of the RSVP path message, the Label object supports the distribution of labels from
downstream nodes to upstream nodes.
Flexible LSP Calculation and Configuration
Traffic engineering involves mapping traffic flow onto a physical topology. You can
determine the paths online using constraint-based routing. Regardless of how the physical
path is calculated, the forwarding state is installed across the network through RSVP.
The Junos OS supports the following ways to route and configure an LSP:
•
You can calculate the full path for the LSP offline and individually configure each router
in the LSP with the necessary static forwarding state. This is analogous to the way
some Internet service providers (ISPs) configure their IP-over-ATM cores.
•
You can calculate the full path for the LSP offline and statically configure the ingress
router with the full path. The ingress router then uses RSVP as a dynamic signaling
protocol to install a forwarding state in each router along the LSP.
•
You can rely on constraint-based routing to perform dynamic online LSP calculation.
You configure the constraints for each LSP; then the network itself determines the
path that best meets those constraints. Specifically, the ingress router calculates the
entire LSP based on the constraints and then initiates signaling across the network.
•
You can calculate a partial path for an LSP offline and statically configure the ingress
router with a subset of the routers in the path; then you can permit online calculation
to determine the complete path.
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Junos OS 11.4 MPLS Applications Configuration Guide
For example, consider a topology that includes two east-west paths across the United
States: one in the north through Chicago and one in the south through Dallas. If you
want to establish an LSP between a router in New York and one in San Francisco, you
can configure the partial path for the LSP to include a single loose-routed hop of a
router in Dallas. The result is an LSP routed along the southern path. The ingress router
uses CSPF to compute the complete path and RSVP to install the forwarding state
along the LSP.
•
You can configure the ingress router with no constraints whatsoever. In this case,
normal IGP shortest-path routing is used to determine the path of the LSP. This
configuration does not provide any value in terms of traffic engineering. However, it is
easy and might be useful in situations when services such as virtual private networks
(VPNs) are needed.
In all these cases, you can specify any number of LSPs as backups for the primary LSP,
thus allowing you to combine more than one configuration approach. For example, you
might explicitly compute the primary path offline, set the secondary path to be
constraint-based, and have the tertiary path be unconstrained. If a circuit on which the
primary LSP is routed fails, the ingress router notices the outage from error notifications
received from a downstream router or by the expiration of RSVP soft-state information.
Then the router dynamically forwards traffic to a hot-standby LSP or calls on RSVP to
create a forwarding state for a new backup LSP.
8
Copyright © 2011, Juniper Networks, Inc.
CHAPTER 2
Complete MPLS Applications
Configuration Statements
This chapter is organized as follows:
•
[edit logical-systems] Hierarchy Level on page 9
•
[edit protocols connections] Hierarchy Level on page 10
•
[edit protocols ldp] Hierarchy Level on page 10
•
[edit protocols link-management] Hierarchy Level on page 12
•
[edit protocols mpls] Hierarchy Level on page 13
•
[edit protocols rsvp] Hierarchy Level on page 17
[edit logical-systems] Hierarchy Level
The following MPLS protocol statements can be configured at the [edit logical-systems]
hierarchy level. This is not a comprehensive list of statements available for logical systems.
Only the statements that are also documented in this manual are listed here. For more
information about logical systems, see the Junos OS Routing Protocols Configuration Guide.
NOTE: Beginning with Junos OS Release 9.3, the logical router feature has
been renamed logical system.
All configuration statements, operational commands, show command
outputs, error messages, log messages, and SNMP MIB objects that contain
the string logical-router or logical-routers have been changed to
logical-system and logical-systems, respectively.
logical-systems {
logical-system-name {
protocols {
connections {
connections-configuration;
}
ldp {
ldp-configuration;
}
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link-management {
link-management-configuration;
}
mpls {
mpls-configuration;
}
rsvp {
rsvp-configuration;
}
}
}
}
[edit protocols connections] Hierarchy Level
The following statements can also be configured at the [edit
logical-systems logical-system-name] hierarchy level:
protocols {
connections {
interface-switch connection-name {
interface interface-name.unit-number;
}
lsp-switch connection-name {
transmit-lsp label-switched-path;
receive-lsp label-switched-path;
}
p2mp-receive-switch {
output-interface interface-name.unit-number;
receive-p2mp-lsp receiving-point-to-multipoint-lsp;
}
p2mp-transmit-switch {
input-interface input-interface-name.unit-number;
transmit-p2mp-lsp transmitting-point-to-multipoint-lsp;
}
remote-interface-switch connection-name {
interface interface-name.unit-number;
transmit-lsp label-switched-path;
receive-lsp label-switched-path;
}
}
}
[edit protocols ldp] Hierarchy Level
The following statements can also be configured at the [edit
logical-systems logical-system-name] hierarchy level:
protocols {
ldp {
(deaggregate | no-deaggregate);
egress-policy [ policy-names ];
explicit-null;
export [ policy-names ];
graceful-restart {
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Chapter 2: Complete MPLS Applications Configuration Statements
disable;
helper-disable;
maximum-neighbor-recovery-time seconds;
reconnect-time seconds;
recovery-time seconds;
}
import [ policy-names];
interface (interface-name | all) {
disable;
hello-interval seconds;
hold-time seconds;
transport-address (interface | router-id);
}
keepalive-interval seconds;
keepalive-timeout seconds;
log-updown {
trap disable;
}
no-forwarding;
oam {
bfd-liveness-detection {
detection-time threshold milliseconds;
ecmp;
failure-action {
remove-nexthop;
remove-route;
}
holddown-interval milliseconds;
minimum-interval milliseconds;
minimum-receive-interval milliseconds;
minimum-transmit-interval milliseconds;
multiplier detection-time-multiplier;
no-adaptation;
transmit-interval {
minimum-interval milliseconds;
threshold milliseconds;
}
}
fec fec-address;
ingress-policy ingress-policy-name;
periodic-traceroute {
disable;
exp exp-value;
fanout fanout-value;
frequency minutes;
paths number-of-paths;
retries retry-attempts;
source address;
ttl ttl-value;
wait seconds;
}
}
p2mp;
policing {
fec fec-address {
ingress-traffic filter-name;
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Junos OS 11.4 MPLS Applications Configuration Guide
transit-traffic filter-name;
}
}
preference preference;
session address {
authentication-key md5-authentication-key;
}
strict-targeted-hellos;
traceoptions {
file filename <files number <size size> <world-readable | no-world-readable>;
flag flag <flag-modifier> <disable>;
}
track-igp-metric;
traffic-statistics {
file filename <files number> <size size> <world-readable | no-world-readable>;
interval interval;
no-penultimate-hop;
}
transport-address (address | interface | router-id);
}
}
[edit protocols link-management] Hierarchy Level
The following statements can also be configured at the [edit
logical-systems logical-system-name] hierarchy level:
protocols {
link-management {
peer peer-name {
address address;
control-channel [ control-channel-interfaces ];
te-link [te-link-names];
}
te-link te-link-name {
disable;
interface interface-name {
disable;
local-address address;
remote-address address;
remote-id id-number;
}
label-switched-path label-switched-path-name;
local-address address;
remote-address address;
remote-id id-number;
}
traceoptions {
file filename <files number> <size size> <world-readable | no-world-readable>;
flag flag <flag-modifier> <disable>;
}
}
}
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Chapter 2: Complete MPLS Applications Configuration Statements
[edit protocols mpls] Hierarchy Level
The following statements can also be configured at the [edit
logical-systems logical-system-name] hierarchy level:
protocols {
mpls {
disable;
admin-group {
exclude [ group-names ];
include-all [ group-names ];
include-any [ group-names ];
}
admin-groups {
group-name group-value;
}
advertisement-hold-time seconds;
auto-policing {
class all (drop | loss-priority-high | loss-priority-low);
class ctnumber (drop | loss-priority-high | loss-priority-low);
}
bandwidth bps {
ct0 bps;
ct1 bps;
ct2 bps;
ct3 bps;
}
class-of-service cos-value;
diffserv-te {
bandwidth-model {
extended-mam;
mam;
rdm;
}
te-class-matrix {
tenumber {
priority priority;
traffic-class ctnumber priority priority;
}
}
}
explicit-null;
hop-limit number;
icmp-tunneling;
interface (interface-name | all) {
disable;
admin-group [group-names];
srlg srlg-name;
}
ipv6-tunneling;
label-switched-path lsp-name {
disable;
adaptive;
admin-down;
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Junos OS 11.4 MPLS Applications Configuration Guide
admin-group {
exclude [ group-names ];
include-all;
include-any [ group-names ];
}
auto-bandwidth {
adjust-interval seconds;
adjust-threshold percent;
maximum-bandwidth bps;
minimum-bandwidth bps;
monitor-bandwidth;
}
bandwidth bps {
ct0 bps;
ct1 bps;
ct2 bps;
ct3 bps;
}
class-of-service cos-value;
description text;
exclude-srlg;
fast-reroute {
(bandwidth bps | bandwidth-percent percent);
(exclude [ group-names ] | no-exclude);
hop-limit number;
(include-all [ group-names ] | no-include-all);
(include-any [ group-names ] | no-include-any);
}
from address;
hop-limit number;
install {
destination-prefix/prefix-length <active>;
}
ldp-tunneling;
link-protection;
lsp-attributes {
encoding-type (ethernet | packet | pdh | sonet-sdh);
gpid (ethernet | hdlc | ipv4 | ppp);
signal-bandwidth type;
switching-type (fiber | lambda | psc-1 | tdm);
}
metric number;
no-cspf;
no-decrement-ttl;
node-link-protection;
optimize-timer seconds;
p2mp path-name;
policing {
filter filter-name;
no-auto-policing;
}
preference preference;
primary path-name {
adaptive;
admin-group {
exclude [ group-names ];
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Chapter 2: Complete MPLS Applications Configuration Statements
include-all [ group-names ];
include-any [ group-names ];
}
bandwidth bps {
ct0 bps;
ct1 bps;
ct2 bps;
ct3 bps;
}
class-of-service cos-value;
hop-limit number;
no-cspf;
no-decrement-ttl;
optimize-timer seconds;
preference preference;
priority setup-priority reservation-priority;
(record | no-record);
select (manual | unconditional);
}
standby;
}
priority setup-priority reservation-priority;
(random | least-fill | most-fill);
(record | no-record);
retry-limit number;
retry-timer seconds;
revert-timer seconds;
secondary path-name {
adaptive;
admin-group {
exclude [ group-names ];
include-all [ group-names ];
include-any [ group-names ];
}
bandwidth bps {
ct0 bps;
ct1 bps;
ct2 bps;
ct3 bps;
}
class-of-service cos-value;
hop-limit number;
no-cspf;
no-decrement-ttl;
optimize-timer seconds;
preference preference;
priority setup-priority reservation-priority;
(record | no-record);
select (manual | unconditional);
standby;
}
soft-preemption;
standby;
to address;
traceoptions {
file filename <files number> <size size> <world-readable | no-world-readable>;
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Junos OS 11.4 MPLS Applications Configuration Guide
flag flag <flag-modifier> <disable>;
}
}
log-updown {
no-trap {
mpls-lsp-traps;
rfc3812-traps;
}
(syslog | no-syslog);
trap;
trap-path-down;
trap-path-up;
}
no-cspf;
no-decrement-ttl;
no-propagate-ttl;
optimize-aggressive;
optimize-timer seconds;
path path-name {
(address | hostname) <strict | loose>;
}
path-mtu {
allow-fragmentation;
rsvp {
mtu-signaling;
}
}
preference preference;
priority setup-priority reservation-priority;
(record | no-record);
revert-timer seconds;
rsvp-error-hold-time seconds;
smart-optimize-timer seconds;
standby;
static-label-switched-path lsp-name {
bypass bypass-name {
bandwidth bps;
description string;
next-hop (address | interface-name | address/interface-name);
push out-label;
to address;
}
ingress {
bandwidth bps;
class-of-service cos-value;
description string;
install {
destination-prefix <active>;
}
link-protection bypass-name name;
metric metric;
next-hop (address | interface-name | address/interface-name);
node-protection bypass-name name next-next-label label;
no-install-to-address;
policing {
filter filter-name;
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Chapter 2: Complete MPLS Applications Configuration Statements
no-auto-policing;
}
preference preference;
push out-label;
to address;
}
transit incoming-label {
bandwidth bps;
description string;
link-protection bypass-name name;
next-hop (address | interface-name | address/interface-name);
node-protection bypass-name name next-next-label label;
pop;
swap out-label;
}
statistics {
auto-bandwidth;
file filename <files number> <size size> <world-readable | no-world-readable>;
interval seconds;
}
traceoptions {
file filename <files number> <size size> <world-readable | no-world-readable>;
flag flag;
}
traffic-engineering (bgp | bgp-igp | bgp-igp-both-ribs | mpls-forwarding);
}
[edit protocols rsvp] Hierarchy Level
The following statements can also be configured at the [edit
logical-systems logical-system-name] hierarchy level:
protocols {
rsvp {
disable;
fast-reroute optimize-timer seconds;
graceful-deletion-timeout seconds;
graceful-restart {
disable;
helper-disable;
maximum-helper-recovery-time seconds;
maximum-helper-restart-time seconds;
}
interface interface-name {
disable;
(aggregate | no-aggregate);
authentication-key key;
bandwidth bps;
hello-interval seconds;
link-protection {
disable;
admin-group {
exclude group-names;
include-all group-names;
include-any group-names;
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Junos OS 11.4 MPLS Applications Configuration Guide
}
bandwidth bandwidth;
bypass bypass-name {
bandwidth bps {
ct0 bps;
ct1 bps;
ct2 bps;
ct3 bps;
}
description text;
hop-limit number;
no-cspf;
path address <strict | loose>;
priority setup-priority reservation-priority;
to address;
}
class-of-service cos-value;
exclude-srlg;
hop-limit number;
max-bypasses number;
no-cspf;
no-node-protection;
optimize-timer seconds;
path address <strict | loose>;
priority setup-priority reservation-priority;
subscription percentage {
ct0 percentage;
ct1 percentage;
ct2 percentage;
ct3 percentage;
}
}
(reliable | no-reliable);
subscription percentage {
ct0 percentage;
ct1 percentage;
ct2 percentage;
ct3 percentage;
}
update-threshold percentage;
}
keep-multiplier number;
load-balance {
bandwidth;
}
no-node-id-subobject;
no-p2mp-sublsp;
peer-interface peer-interface-name {
(aggregate | no-aggregate);
authentication-key key;
disable;
hello-interval seconds;
(reliable | no-reliable);
}
preemption {
(aggressive | disabled | normal);
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Chapter 2: Complete MPLS Applications Configuration Statements
soft-preemption {
cleanup-timer seconds;
}
}
refresh-time seconds;
traceoptions {
file filename <files number> <size size> <world-readable | no-world-readable>;
flag flag <flag-modifier> <disable>;
}
tunnel-services {
devices device-names;
}
}
}
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
20
Copyright © 2011, Juniper Networks, Inc.
PART 2
MPLS
•
MPLS Overview on page 23
•
MPLS Router Configuration Guidelines on page 55
•
MPLS-Signaled LSP Configuration Guidelines on page 125
•
DiffServ-Aware Traffic Engineering Configuration Guidelines on page 169
•
Static and Explicit-Path LSP Configuration Guidelines on page 193
•
Point-to-Multipoint LSP Configuration Guidelines on page 203
•
Miscellaneous MPLS Properties Configuration Guidelines on page 213
•
Summary of MPLS Configuration Statements on page 239
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
22
Copyright © 2011, Juniper Networks, Inc.
CHAPTER 3
MPLS Overview
This chapter discusses the following topics:
•
MPLS Introduction on page 24
•
Supported MPLS Standards on page 24
•
Link-Layer Support on page 26
•
MPLS and Traffic Engineering on page 27
•
Label Description on page 27
•
Special Labels on page 28
•
Label Allocation on page 28
•
Operations on Labels on page 30
•
Routers in an LSP on page 30
•
How a Packet Travels Along an LSP on page 31
•
Types of LSPs on page 31
•
Scope of LSPs on page 32
•
Constrained-Path LSP Computation on page 32
•
How CSPF Selects a Path on page 33
•
Path Selection Tie-Breaking on page 34
•
Computing Paths Offline on page 34
•
LSPs on an Overloaded Router on page 35
•
Fate Sharing on page 35
•
SRLG Overview on page 36
•
IGP Shortcuts on page 37
•
Enabling IGP Shortcuts on page 38
•
LSPs Qualified in Shortcut Computations on page 38
•
IGP Shortcut Applications on page 39
•
IGP Shortcuts and Routing Table on page 39
•
IGP Shortcuts and VPNs on page 40
•
Advertising LSPs into IGPs on page 40
•
IP and MPLS Packets on Aggregated Interfaces on page 41
Copyright © 2011, Juniper Networks, Inc.
23
Junos OS 11.4 MPLS Applications Configuration Guide
•
MPLS Applications on page 42
•
BGP Destinations on page 42
•
IGP and BGP Destinations on page 44
•
Selecting a Forwarding LSP Next Hop on page 44
•
MPLS and Routing Tables on page 45
•
MPLS and Traffic Protection on page 46
•
Fast Reroute on page 47
•
Fast Reroute Overview on page 47
•
Detour Merging Process on page 49
•
Detour Computations on page 50
•
Fast Reroute Path Optimization on page 51
•
Automatic Bandwidth Allocation on page 51
•
Point-to-Multipoint LSPs Overview on page 52
MPLS Introduction
MPLS provides a mechanism for engineering network traffic patterns that is independent
of routing tables. MPLS assigns short labels to network packets that describe how to
forward them through the network. MPLS is independent of any routing protocol and
can be used for unicast packets.
In the traditional Level 3 forwarding paradigm, as a packet travels from one router to the
next, an independent forwarding decision is made at each hop. The IP network layer
header is analyzed, and the next hop is chosen based on this analysis and on the
information in the routing table. In an MPLS environment, the analysis of the packet
header is performed just once, when a packet enters the MPLS cloud. The packet is then
assigned to a stream, which is identified by a label, which is a short (20-bit), fixed-length
value at the front of the packet. Labels are used as lookup indexes for the label forwarding
table. For each label, this table stores forwarding information. You can associate additional
information with a label—such as class-of-service (CoS) values—that can be used to
prioritize packet forwarding.
Supported MPLS Standards
The Junos OS substantially supports the following RFCs and Internet drafts, which define
standards for MPLS and traffic engineering.
•
RFC 2858, Multiprotocol Extensions for BGP-4
•
RFC 3031, Multiprotocol Label Switching Architecture
•
RFC 3032, MPLS Label Stack Encoding
•
RFC 3140, Per Hop Behavior Identification Codes
•
RFC 3270, Multi-Protocol [sic] Label Switching (MPLS) Support of Differentiated Services
Only E-LSPs are supported.
24
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Chapter 3: MPLS Overview
•
RFC 3443, Time To Live (TTL) Processing in Multi-Protocol [sic] Label Switching (MPLS)
Networks
•
RFC 3478, Graceful Restart Mechanism for Label Distribution Protocol
•
RFC 4090, Fast Reroute Extensions to RSVP-TE for LSP Tunnels
Node protection in facility backup is not supported.
•
RFC 4124, Protocol Extensions for Support of Diffserv-aware MPLS Traffic Engineering
•
RFC 4364, BGP/MPLS IP Virtual Private Networks (VPNs)
•
RFC 4379, Detecting Multi-Protocol [sic] Label Switched (MPLS) Data Plane Failures
The traceroute functionality is supported only on transit routers.
•
RFC 4950, ICMP Extensions for Multiprotocol Label Switching
•
Internet draft draft-ietf-bfd-mpls-02.txt, BFD for MPLS LSPs
•
Internet draft draft-ietf-mpls-rsvp-te-p2mp-01.txt, Extensions to RSVP-TE for Point to
Multipoint TE LSPs (expires June 2005)
•
Internet draft draft-ietf-mpls-soft-preemption-02.txt, MPLS Traffic Engineering Soft
preemption
The following RFCs and Internet drafts do not define standards, but provide information
about MPLS, traffic engineering, and related technologies. The IETF classifies them
variously as “Experimental,” “Historic,” or “Informational.”
•
RFC 2547, BGP/MPLS VPNs
•
RFC 2702, Requirements for Traffic Engineering Over MPLS
•
RFC 3063, MPLS Loop Prevention Mechanism
•
RFC 3208, PGM Reliable Transport Protocol Specification
Only the network element is supported.
•
RFC 3469, Framework for Multi-Protocol [sic] Label Switching (MPLS)-based Recovery
•
RFC 3564, Requirements for Support of Differentiated Services-aware MPLS Traffic
Engineering
•
RFC 4125, Maximum Allocation Bandwidth Constraints Model for Diffserv-aware MPLS
Traffic Engineering
•
RFC 4127, Russian Dolls Bandwidth Constraints Model for Diffserv-aware MPLS Traffic
Engineering
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
•
Internet draft draft-martini-l2circuit-encap-mpls-11.txt, Encapsulation Methods for
Transport of Layer 2 Frames Over IP and MPLS Networks
The Junos OS differs from the Internet draft in the following ways:
•
A packet with a sequence number of 0 is treated as out of sequence.
•
Any packet which does not have the next incremental sequence number is considered
out of sequence.
•
When out-of-sequence packets arrive, the expected sequence number for the
neighbor is set to the sequence number in the Layer 2 circuit control word.
•
Internet draft draft-martini-l2circuit-trans-mpls-19.txt, Transport of Layer 2 Frames
Over MPLS
•
Internet draft draft-raggarwa-mpls-p2mp-te-02.txt, Establishing Point to Multipoint
MPLS TE LSPs
The features discussed in the indicated sections of the draft are not supported:
Related
Documentation
•
Nonadjacent signaling for branch LSPs (section 7.1)
•
Make-before-break and fast reroute (section 9)
•
LSP hierarchy using point-to-point LSPs (section 10)
•
Supported GMPLS Standards on page 541
•
Supported LDP Standards on page 426
•
Supported RSVP Standards on page 338
•
Accessing Standards Documents on the Internet
Link-Layer Support
MPLS supports the following link-layer protocols, which are all supported in the Junos
OS MPLS implementation:
26
•
Point-to-Point Protocol (PPP)—Protocol ID 0x0281, Network Control Protocol (NCP)
protocol ID 0x8281.
•
Ethernet/Cisco High-level Data Link Control (HDLC)—Ethernet type 0x8847.
•
Asynchronous Transfer Mode (ATM)—Subnetwork attachment point encoded
(SNAP-encoded) Ethernet type 0x8847. Support is included for both point-to-point
mode or nonbroadcast multiaccess (NBMA) mode. Support is not included for encoding
MPLS labels as part of ATM virtual path identifier/virtual circuit identifier (VPI/VCI).
•
Frame Relay—SNAP-encoded, Ethernet type 0x8847. Support is not included for
encoding MPLS labels as part of Frame Relay data-link connection identifier (DLCI).
•
Generic routing encapsulation (GRE) tunnel—Ethernet type 0x8847.
Copyright © 2011, Juniper Networks, Inc.
Chapter 3: MPLS Overview
MPLS and Traffic Engineering
Traffic engineering allows you to control the path that data packets follow, bypassing
the standard routing model, which uses routing tables. Traffic engineering moves flows
from congested links to alternate links that would not be selected by the automatically
computed destination-based shortest path. With traffic engineering, you can:
•
Make more efficient use of expensive long-haul fibers.
•
Control how traffic is rerouted in the face of single or multiple failures.
•
Classify critical and regular traffic on a per-path basis.
The core of the traffic engineering design is based on building label-switched paths
(LSPs) among routers. An LSP is connection-oriented, like a virtual circuit in Frame Relay
or ATM. LSPs are not reliable: Packets entering an LSP do not have delivery guarantees,
although preferential treatment is possible. LSPs also are similar to unidirectional tunnels
in that packets entering a path are encapsulated in an envelope and switched across the
entire path without being touched by intermediate nodes. LSPs provide fine-grained
control over how packets are forwarded in a network. To provide reliability, an LSP can
use a set of primary and secondary paths.
LSPs can be configured for BGP traffic only (traffic whose destination is outside of an
autonomous system [AS]). In this case, traffic within the AS is not affected by the
presence of LSPs. LSPs can also be configured for both BGP and interior gateway protocol
(IGP) traffic; therefore, both intra-AS and inter-AS traffic is affected by the LSPs.
This section discusses the following topics:
•
Label Description on page 27
•
Label Allocation on page 28
•
Routers in an LSP on page 30
•
How a Packet Travels Along an LSP on page 31
•
Types of LSPs on page 31
•
Scope of LSPs on page 32
•
Constrained-Path LSP Computation on page 32
•
LSPs on an Overloaded Router on page 35
•
Fate Sharing on page 35
•
IGP Shortcuts on page 37
•
Advertising LSPs into IGPs on page 40
Label Description
Packets traveling along an LSP are identified by a label—a 20-bit, unsigned integer in the
range 0 through 1,048,575. For push labels on ingress routers, no labels in this range are
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restricted. For incoming labels on the transit static LSP, the label value is restricted to
1,000,000 through 1,048,575.
Special Labels
Some of the reserved labels (in the 0 through 15 range) have well-defined meanings. For
more complete details, see RFC 3032, MPLS Label Stack Encoding.
•
0, IPv4 Explicit Null label—This value is legal only when it is the sole label entry (no
label stacking). It indicates that the label must be popped upon receipt. Forwarding
continues based on the IP version 4 (IPv4) packet.
•
1, Router Alert label—When a packet is received with a top label value of 1, it is delivered
to the local software module for processing.
•
2, IPv6 Explicit Null label—This value is legal only when it is the sole label entry (no
label stacking). It indicates that the label must be popped on receipt. Forwarding
continues based on the IP version 6 (IPv6) packet.
•
3, Implicit Null label—This label is used in the control protocol (LDP or RSVP) only to
request label popping by the downstream router. It never actually appears in the
encapsulation. Labels with a value of 3 should not be used in the data packet as real
labels. No payload type (IPv4 or IPv6) is implied with this label.
•
4 through 15—Unassigned.
Special labels are commonly used between the egress and penultimate routers of an
LSP. If the LSP is configured to carry IPv4 packets only, the egress router might signal
the penultimate router to use 0 as a final-hop label. If the LSP is configured to carry IPv6
packets only, the egress router might signal the penultimate router to use 2 as a final-hop
label.
The egress router might simply signal the penultimate router to use 3 as the final label,
which is a request to perform penultimate-hop label popping. The egress router will not
process a labeled packet; rather, it receives the payload (IPv4, IPv6, or others) directly,
reducing one MPLS lookup at egress.
For label-stacked packets, the egress router receives an MPLS label packet with its top
label already popped by the penultimate router. The egress router cannot receive
label-stacked packets that use label 0 or 2. It typically requests label 3 from the
penultimate router.
Label Allocation
In the Junos OS, label values are allocated per router. The display output shows only the
label (for example, 01024). Labels for multicast packets are independent of those for
unicast packets. Currently, the Junos OS does not support multicast labels.
Labels are assigned by downstream routers relative to the flow of packets. A router
receiving labeled packets (the next-hop router) is responsible for assigning incoming
labels. A received packet containing a label that is unrecognized (unassigned) is dropped.
For unrecognized labels, the router does not attempt to unwrap the label to analyze the
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Chapter 3: MPLS Overview
network layer header, nor does it generate an Internet Control Message Protocol (ICMP)
destination unreachable message.
A packet can carry a number of labels, organized as a last-in, first-out stack. This is
referred to as a label stack. At a particular router, the decision about how to forward a
labeled packet is based exclusively on the label at the top of the stack.
Figure 1 on page 29 shows the encoding of a single label. The encoding appears after
data link layer headers, but before any network layer header.
Figure 1: Label Encoding
Figure 2 on page 29 illustrates the purpose of the class-of-service bits (also known as
the EXP or experimental bits). Bits 20 and 21 specify the queue number. Bit 22 is the
packet loss priority (PLP) bit used to specify the random early detection (RED) drop
profile. For more information about class of service and the class-of-service bits, see
“Configuring Class of Service for MPLS LSPs” on page 157.
Figure 2: Class-of-Service Bits
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Operations on Labels
The router supports the following label operations:
•
Push—Add a new label to the top of the packet. For IPv4 packets, the new label is the
first label. The time-to-live (TTL) and s bits are derived from the IP packet header. The
MPLS class of service (CoS) is derived from the queue number. If the push operation
is performed on an existing MPLS packet, you will have a packet with two or more
labels. This is called label stacking. The top label must have its s bit set to 0, and might
derive CoS and TTL from lower levels. The new top label in a label stack always
initializes its TTL to 255, regardless of the TTL value of lower labels.
•
Pop—Remove the label from the beginning of the packet. Once the label is removed,
the TTL is copied from the label into the IP packet header, and the underlying IP packet
is forwarded as a native IP packet. In the case of multiple labels in a packet (label
stacking), removal of the top label yields another MPLS packet. The new top label
might derive CoS and TTL from a previous top label. The popped TTL value from the
previous top label is not written back to the new top label.
•
Swap—Replace the label at the top of the label stack with a new label. The S and CoS
bits are copied from the previous label, and the TTL value is copied and decremented
(unless the no-decrement-ttl or no-propagate-ttl statement is configured). A transit
router supports a label stack of any depth.
•
Multiple Push—Add multiple labels (up to three) on top of existing packets. This
operation is equivalent to pushing multiple times.
•
Swap and Push—Replace the existing top of the label stack with a new label, and then
push another new label on top.
Routers in an LSP
Each router in an LSP performs one of the following functions:
30
•
Ingress router—The router at the beginning of an LSP. This router encapsulates IP
packets with an MPLS Layer 2 frame and forwards it to the next router in the path.
Each LSP can have only one ingress router.
•
Egress router—The router at the end of an LSP. This router removes the MPLS
encapsulation, thus transforming it from an MPLS packet to an IP packet, and forwards
the packet to its final destination using information in the IP forwarding table. Each
LSP can have only one egress router. The ingress and egress routers in an LSP cannot
be the same router.
•
Transit router—Any intermediate router in the LSP between the ingress and egress
routers. A transit router forwards received MPLS packets to the next router in the MPLS
path. An LSP can contain zero or more transit routers, up to a maximum of 253 transit
routers in a single LSP.
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Chapter 3: MPLS Overview
A single router can be part of multiple LSPs. It can be the ingress or egress router for one
or more LSPs, and it also can be a transit router in one or more LSPs. The functions that
each router supports depend on your network design.
How a Packet Travels Along an LSP
When an IP packet enters an LSP, the ingress router examines the packet and assigns it
a label based on its destination, placing the label in the packet’s header. The label
transforms the packet from one that is forwarded based on its IP routing information to
one that is forwarded based on information associated with the label.
The packet is then forwarded to the next router in the LSP. This router and all subsequent
routers in the LSP do not examine any of the IP routing information in the labeled packet.
Rather, they use the label to look up information in their label forwarding table. They
then replace the old label with a new label and forward the packet to the next router in
the path.
When the packet reaches the egress router, the label is removed, and the packet again
becomes a native IP packet and is again forwarded based on its IP routing information.
Types of LSPs
There are three types of LSPs:
•
Static LSPs—For static paths, you must manually assign labels on all routers involved
(ingress, transit, and egress). No signaling protocol is needed. This procedure is similar
to configuring static routes on individual routers. Like static routes, there is no error
reporting, liveliness detection, or statistics reporting.
•
LDP-signaled LSPs—See “LDP Introduction” on page 425.
•
RSVP-signaled LSPs—For signaled paths, RSVP is used to set up the path and
dynamically assign labels. (RSVP signaling messages are used to set up signaled
paths.) You configure only the ingress router. The transit and egress routers accept
signaling information from the ingress router, and they set up and maintain the LSP
cooperatively. Any errors encountered while establishing an LSP are reported to the
ingress router for diagnostics. For signaled LSPs to work, a version of RSVP that supports
tunnel extensions must be enabled on all routers.
There are two types of RSVP-signaled LSPs:
•
Explicit-path LSPs—All intermediate hops of the LSP are manually configured. The
intermediate hops can be strict, loose, or any combination of the two. Explicit path
LSPs provide you with complete control over how the path is set up. They are similar
to static LSPs but require much less configuration.
•
Constrained-path LSPs—The intermediate hops of the LSP are automatically computed
by the software. The computation takes into account information provided by the
topology information from the IS-IS or OSPF link-state routing protocol, the current
network resource utilization determined by RSVP, and the resource requirements and
constraints of the LSP. For signaled constrained-path LSPs to work, either the IS-IS or
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OSPF protocol and the IS-IS or OSPF traffic engineering extensions must be enabled
on all routers.
Scope of LSPs
For constrained-path LSPs, the LSP computation is confined to one IGP domain, and
cannot cross any AS boundary. This prevents an AS from extending its IGP into another
AS.
Explicit-path LSPs, however, can cross as many AS boundaries as necessary. Because
intermediate hops are manually specified, the LSP does not depend on the IGP topology
or a local forwarding table.
Constrained-Path LSP Computation
The Constrained Shortest Path First (CSPF) algorithm is an advanced form of the
shortest-path-first (SPF) algorithm used in OSPF and IS-IS route computations. CSPF
is used in computing paths for LSPs that are subject to multiple constraints. When
computing paths for LSPs, CSPF considers not only the topology of the network, but also
the attributes of the LSP and the links, and it attempts to minimize congestion by
intelligently balancing the network load.
The constraints that CSPF considers include:
•
•
LSP attributes
•
Administrative groups (that is, link color requirements)
•
Bandwidth requirements
•
Explicit route (strict or loose)
•
Hop limitations
•
Priority (setup and hold)
Link attributes
•
Administrative groups (that is, link colors assigned to the link)
•
Reservable bandwidth of the links (static bandwidth minus the currently reserved
bandwidth)
The data that CSPF considers comes from the following sources:
•
32
Traffic engineering database—Provides CSPF with up-to-date topology information,
the current reservable bandwidth of links, and the link colors. For the CSPF algorithm
to perform its computations, a link-state IGP (such as OSPF or IS-IS) with special
extensions is needed. For CSPF to be effective, the link-state IGP on all routers must
support the special extensions. While building the topology database, the extended
IGP must take into consideration the current LSPs and must flood the route information
everywhere. Because changes in the reserved link bandwidth and link color cause
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Chapter 3: MPLS Overview
database updates, an extended IGP tends to flood more frequently than a normal IGP.
See Figure 3 on page 33 for a diagram of the relationships between these components.
•
Currently active LSPs—Includes all the LSPs that should originate from the router and
their current operational status (up, down, or timeout).
Figure 3: CSPF Computation Process
This section discusses the following topics:
•
How CSPF Selects a Path on page 33
•
Path Selection Tie-Breaking on page 34
•
Computing Paths Offline on page 34
How CSPF Selects a Path
To select a path, CSPF follows these steps:
1.
Computes LSPs one at a time, beginning with the highest priority LSP (the one with
the lowest setup priority value). Among LSPs of equal priority, CSPF starts with those
that have the highest bandwidth requirement.
2. Prunes the traffic engineering database of all the links that are not full duplex and do
not have sufficient reservable bandwidth.
3. If the LSP configuration includes the include statement, prunes all links that do not
share any included colors.
4. If the LSP configuration includes the exclude statement, prunes all links that contain
excluded colors. If the link does not have a color, it is accepted.
5. Finds the shortest path toward the LSP’s egress router, taking into account
explicit-path constraints. For example, if the path must pass through Router A, two
separate SPFs are computed, one from the ingress router to Router A, the other from
Router A to the egress router.
6. If several paths have equal cost, chooses the one whose last-hop address is the same
as the LSP’s destination.
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7. If several equal-cost paths remain, selects the one with the fewest number of hops.
8. If several equal-cost paths remain, applies the CSPF load-balancing rule configured
on the LSP (least fill, most fill, or random).
Path Selection Tie-Breaking
If more than one path is available after the rules from the previous section have been
applied, a tie-breaking rule is applied to choose the path for the LSP. There are three
tie-breaking rules:
•
Random—One of the remaining paths is picked at random. This rule tends to place an
equal number of LSPs on each link, regardless of the available bandwidth ratio.
•
Least fill—The path with the largest minimum available bandwidth ratio is preferred.
This rule tries to equalize the reservation on each link.
•
Most fill—The path with the smallest minimum available bandwidth ratio is preferred.
This rule tries to fill a link before moving on to alternative links.
The rule used depends on the configuration. Random is the default rule.
For the other rules, the following definitions are needed:
•
Reservable bandwidth = bandwidth of link x subscription factor of link
•
Available bandwidth = reservable bandwidth – (sum of the bandwidths of the LSPs
traversing the link)
•
Available bandwidth ratio = available bandwidth/reservable bandwidth
•
Minimum available bandwidth ratio (for a path) = the smallest available bandwidth
ratio of the links in a path
Computing Paths Offline
The Junos OS provides online, real-time CSPF computation only; each router performs
CSPF calculations independent of the other routers in the network. These calculations
are based on currently available topology information—information that is usually recent,
but not completely accurate. LSP placements are locally optimized, based on current
network status.
To optimize links globally across the network, you can use an offline tool to perform the
CSPF calculations and determine the paths for the LSPs. You can create such a tool
yourself, or you can modify an existing network design tool to perform these calculations.
You should run the tool periodically (daily or weekly) and download the results into the
router. An offline tool should take the following into account when performing the
optimized calculations:
34
•
All the LSP’s requirements
•
All link attributes
•
Complete network topology
Copyright © 2011, Juniper Networks, Inc.
Chapter 3: MPLS Overview
LSPs on an Overloaded Router
An overloaded router is a router running IS-IS with its overload bit set in its IS-IS
configuration. In this case, an MPLS LSP specifically refers to an RSVP-signaled or
LDP-signaled LSP. In the case of RSVP, it applies to both CSPF and non-CSPF LSPs.
You cannot establish transit LSPs through an overloaded router. However, you can
configure ingress and egress LSPs through an overloaded router.
NOTE: When you set the overload bit on an IS-IS router, all LSPs transiting
through it are recomputed and rerouted away from it. If the recomputation
fails, no additional attempt to reconfigure the LSP is made, and the affected
LSPs are disconnected.
An example of when you might want to establish transit LSPs through an overloaded
router is illustrated in Figure 4 on page 35, which shows an aggregation router
(Router A) dual-homed on two core routers (Router B and Router C). You want to include
the aggregation router in the LSP mesh, but transit LSPs should not pass through it,
because it is a less capable router with relatively low-bandwidth uplinks to the core.
Certain failure and rerouting scenarios could make it impossible for the aggregation router
to establish some of its LSPs. Consequently, you run the router in a steady state with the
overload bit set, but you are still able to establish ingress and egress LSPs through it.
Figure 4: Aggregation Router A Dual-Homed on Core Routers B and C
Fate Sharing
Fate sharing allows you to create a database of information that CSPF uses to compute
one or more backup paths to use in case the primary path becomes unstable. The
database describes the relationships between elements of the network, such as routers
and links. You can specify one or more elements within a group.
Through fate sharing, you can configure backup paths that minimize the number of shared
links and fiber paths with the primary paths as much as possible, to ensure that if a fiber
is cut, the minimum amount of data is lost and a path still exists to the destination.
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Junos OS 11.4 MPLS Applications Configuration Guide
For a backup path to work optimally, it must not share links or physical fiber paths with
the primary path, ensuring that a single point of failure will not affect the primary and
backup paths simultaneously. For more information about fate sharing, see the Junos OS
Routing Protocols Configuration Guide.
SRLG Overview
In MPLS traffic engineering, a Shared Risk Link Group (SRLG) is a set of links sharing a
common resource, which affects all links in the set if the common resource fails. These
links share the same risk of failure and are therefore considered to belong to the same
SRLG. For example, links sharing a common fiber are said to be in the same SRLG because
a fault with the fiber might cause all links in the group to fail.
An SRLG is represented by a 32-bit number unique within an IGP (OSPFv2 and IS-IS)
domain. A link might belong to multiple SRLGs. The SRLG of a path in a label-switched
path (LSP) is the set of SRLGs for all the links in the path. When computing the secondary
path for an LSP, it is preferable to find a path such that the secondary and primary paths
do not have any links in common in case the SRLGs for the primary and secondary paths
are disjoint. This ensures that a single point of failure on a particular link does not bring
down both the primary and secondary paths in the LSP.
When the SRLG is configured, the device uses the Constrained Shortest Path First (CSPF)
algorithm and tries to keep the links used for the primary and secondary paths mutually
exclusive. If the primary path goes down, the CSPF algorithm computes the secondary
path by trying to avoid links that share any SRLG with the primary path. In addition, when
computing the path for a bypass LSP, CSPF tries to avoid links that share any SRLG with
the protected links.
When the SRLG is not configured, CSPF only takes into account the costs of the links
when computing the secondary path.
Any change in link SRLG information triggers the IGP to send LSP updates for the new
link SRLG information. CSPF recomputes the paths during the next round of reoptimization.
Junos OS Release 11.4 and later supports SRLG based on the following RFCs:
•
RFC 4203, OSPF Extensions in Support of Generalized Multi-Protocol Label Switching
(GMPLS).
•
RFC 5307, IS-IS Extensions in Support of Generalized Multi-Protocol Label Switching
(GMPLS).
NOTE: Currently, the “Fate Sharing” feature continues to be supported with
the SRLG feature.
Related
Documentation
36
•
Example: Configuring SRLG on page 71
•
Example: Excluding SRLG Links Completely for the Secondary LSP on page 80
•
Example: Configuring SRLG With Link Protection on page 85
Copyright © 2011, Juniper Networks, Inc.
Chapter 3: MPLS Overview
•
Example: Configuring SRLG With Link Protection With the exclude-srlg Option on
page 105
•
Fate Sharing on page 35
IGP Shortcuts
Link-state protocols, such as OSPF and IS-IS, use the SPF algorithm to compute the
shortest-path tree to all nodes in the network. The results of such computations can be
represented by the destination node, next-hop address, and output interface, where the
output interface is a physical interface. LSPs can be used to augment the SPF algorithm,
for the purposes of resolving BGP next hops. On the node performing the calculations,
LSPs appear to be logical interfaces directly connected to remote nodes in the network.
If you configure the IGP to treat LSPs the same as a physical interface and use the LSPs
as a potential output interface, the SPF computation results are represented by the
destination node and output LSP, effectively using the LSP as a shortcut through the
network to the destination.
As an illustration, begin with a typical SPF tree (see Figure 5 on page 37).
Figure 5: Typical SPF Tree, Sourced from Router A
If an LSP connects Router A to Router D and if IGP shortcuts are enabled on Router A,
you might have the SPF tree shown in Figure 6 on page 37.
Figure 6: Modified SPF Tree, Using LSP A–D as a Shortcut
Note that Router D is now reachable through LSP A–D. When computing the shortest
path to reach Router D, Router A has two choices:
•
Use IGP path A–B–D.
•
Use LSP A–D.
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Router A decides between the two choices by comparing the IGP metrics for path A–B–D
with the LSP metrics for LSP A–D. If the IGP metric is lower, path A–B–D is chosen (Figure
5 on page 37). If the LSP metric is lower, LSP A–D is used (Figure 6 on page 37). If both
metrics are equal, LSP A–D is chosen because LSP paths are preferred over IGP paths.
Note that Routers E and F are also reachable through LSP A–D, because they are
downstream from Router D in the SPF tree.
Assuming that another LSP connects Router A to Router E, you might have the SPF tree
shown in Figure 7 on page 38.
Figure 7: Modified SPF Tree, Using LSP A–D and LSP A–E as Shortcuts
This section discusses the following topics:
Related
Documentation
•
Enabling IGP Shortcuts on page 38
•
LSPs Qualified in Shortcut Computations on page 38
•
IGP Shortcut Applications on page 39
•
IGP Shortcuts and Routing Table on page 39
•
IGP Shortcuts and VPNs on page 40
•
Configuring IS-IS Traffic Engineering Attributes
•
OSPF Extensions to Support Traffic Engineering
Enabling IGP Shortcuts
IGP shortcuts are supported for both IS-IS and OSPF. A link-state protocol is required
for IGP shortcuts. Shortcuts are disabled by default. For information about enabling IGP
shortcuts for IS-IS and OSPF, see the Junos OS Routing Protocols Configuration Guide. You
can enable IGP shortcuts on a per-router basis; you do not need to enable shortcuts
globally. A router’s shortcut computation does not depend on another router performing
similar computations, and shortcuts performed by other routers are irrelevant.
LSPs Qualified in Shortcut Computations
Not all LSPs are used in IGP shortcuts. Only those LSPs whose egress point (using the
to statement) matches the router ID of the egress node are considered. Other LSPs,
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Chapter 3: MPLS Overview
whose egress point matches the egress node interface address, are ignored in IGP
shortcuts.
There are exceptions, however. If an LSP has an alias egress point (using the install
statement) and it matches certain router IDs, it is included in the shortcut computation
as well. If multiple equal metric LSPs destined to the same router ID exist, traffic can
load-share among them.
IGP Shortcut Applications
You can use shortcuts to engineer traffic traveling toward destination nodes that do not
support MPLS LSPs. For example, in Figure 7 on page 38, traffic traveling toward Router
F enters LSP A–E. You can control traffic between Router A and Router F by manipulating
LSP A–E; you do not need to explicitly set up an LSP between Router A and Router F.
In Figure 8 on page 39, all traffic from Region 1 to Region 2 traverses LSP A–B if IGP
shortcuts are enabled on the ingress router (Router A), permitting aggregation of
interregional traffic into one LSP. To perform traffic engineering on the interregional
traffic, you have to manipulate LSP A-B only, which avoids creating n2 LSPs from all
routers in Region 1 to all routers in Region 2 and allows efficient resource controls on the
backbone network.
Figure 8: IGP Shortcuts
Shortcuts allow you to deploy LSPs into a network in an incremental, hierarchical fashion.
In Figure 9 on page 39, each region can choose to implement traffic engineering LSPs
independently, without requiring cooperation from other regions. Each region can choose
to deploy intraregion LSPs to fit the region’s bandwidth needs, at the pace appropriate
for the region.
Figure 9: IGP Shortcuts in a Bigger Network
When intraregion LSPs are in place, interregional traffic automatically traverses the
intraregion LSPs as needed, eliminating the need for a full mesh of LSPs between edge
routers. For example, traffic from Router A to Router D traverses LSPs A–B, B–C, and
C–D.
IGP Shortcuts and Routing Table
IGP typically performs two independent computations. The first is performed without
considering any LSP. The result of the computation is stored in the inet.0 table. This step
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Junos OS 11.4 MPLS Applications Configuration Guide
is no different from traditional SPF computations and is always performed even if IGP
shortcut is disabled.
The second computation is performed considering only LSPs as a logical interface. Each
LSP’s egress router is considered. The list of destinations whose shortest path traverses
the egress router (established during the first computation) is placed in the inet.3 routing
table. These destinations are given the egress router of the LSP as a next hop, enabling
BGP on the local router to use these LSPs to access BGP next hops beyond the egress
router. Normally, BGP can use only LSPs that terminate at the BGP next hop. Note that
BGP is the only protocol that uses the inet.3 routing table. Other protocols will not route
traffic through these LSPs.
If traffic engineering for IGP and BGP is enabled (see “IGP and BGP Destinations” on
page 44), IGP moves all routes in inet.3 into inet.0, merging all routes while emptying the
inet.3 table. The number of routes in inet.0 will be exactly the same as before. Route
next-hops can traverse a physical interface, an LSP, or the combination of the two if the
metrics are equal.
IGP shortcuts are enabled on a per-node basis. You do not need to coordinate with
other nodes.
IGP Shortcuts and VPNs
You can configure IGP shortcuts for either IS-IS or OSPF. IGP shortcuts allow the IGP to
use an LSP as the next hop instead of the IGP route. IGP shortcuts can also be enabled
for VPNs by also specifying the bgp-igp-both-ribs or mpls-forwarding options for the
traffic-engineering statement at the [edit protocols mpls] hierarchy level. VPNs are
dependant on routes stored in the inet.3 routing table. The bgp-igp option for the
traffic-engineering statement moves all routes from the inet.3 routing table to the inet.0
routing table and is therefore incompatible with VPNs.
Related
Documentation
•
Configuring Traffic Engineering for LSPs on page 216
•
Configuring IS-IS Traffic Engineering Attributes
•
OSPF Extensions to Support Traffic Engineering
Advertising LSPs into IGPs
You can configure your IGP to treat an LSP as a link. IGP shortcuts allow only the ingress
router of an LSP to use the LSP in its SPF computation. However, other routers on the
network do not know of the existence of that LSP, so they cannot use it. This can lead
to suboptimal traffic engineering. In addition, only BGP can use an IGP shortcut to an
LSP. When you advertise an LSP as a link into the IGP, all traffic can traverse it, and all
routers know about it.
As an example, consider the network shown in Figure 10 on page 41.
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Chapter 3: MPLS Overview
Figure 10: SPF Computations with Advertised LSPs
Assume that Router A is computing a path to Router D. The link between Router E and
Router F has a metric of 20; all other links have a metric of 10. Here, the path chosen by
Router A is A–B–C–D, which has a metric of 30, instead of A–E–F–D, which has a metric
of 40.
If Router E has an LSP to Router D with a metric of 15, you want traffic from Router A to
Router D to use the path A–E–D, which has a metric of 25, instead of the path A–B–C–D.
However, because Router A does not know about the LSP between Router E and Router D,
it cannot route traffic through this path.
For all routers on the network to know about the LSP between Router E and Router D,
you need to advertise it. This advertisement announces the LSP as a unidirectional,
point-to-point link in the link-state database, and all routers can compute paths using
the LSP. The link-state database maintains information about the AS topology and
contains information about the router’s local state (for example, the router’s usable
interfaces and reachable neighbors). In Figure 10 on page 41, Router A will see the link
from Router E to Router D and route traffic along this lower-metric path.
Because an LSP is announced as a unidirectional link, you might need to configure a
reverse LSP (one that starts at the egress router and ends at the ingress router) so that
the SPF bidirectionality check succeeds. As a step in the SPF computation, IS-IS considers
a link from Router E to Router D. Before IS-IS uses any link, it verifies that there is a link
from Router D to Router E (there is bidirectional connectivity between router E and D).
Otherwise, the SPF computation will not use an announced LSP.
When an LSP is advertised to the IGP, the advertising router uses the LSP as the forwarding
path for regular routes after installing them in the inet.0 routing table. All packets
traversing the router could be forwarded through the LSP. Conversely, IGP shortcuts are
used only to forward packets that are following BGP routes.
NOTE: Do not configure IGP shortcuts and advertise LSPs to the IGP at the
same time.
IP and MPLS Packets on Aggregated Interfaces
You can send IP and MPLS packets over aggregated interfaces. To the IP or MPLS session,
there is a single LSP composed of the aggregated interfaces. Packets sent to an LSP
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that is part of an aggregated interface are redistributed over the aggregated member
interfaces.
Sending IP and MPLS packets over aggregated interfaces has the following benefits:
•
Bandwidth aggregation—You can increase the number of MPLS packet flows sent over
each connection. In MPLS, a set of packets sharing the same label is considered a part
of the same flow.
•
Link redundancy—If a link or a line card failure affects an aggregate member link, the
traffic flowing across that link is immediately forwarded across one of the remaining
links.
The Junos OS supports aggregated SONET and Ethernet interfaces.
Note that the Junos implementation of IP and MPLS over aggregated interfaces
(aggregated Ethernet devices only) complies with IEEE 802.3ad.
For information about how to configure aggregated Ethernet or aggregated SONET
interfaces, see the Junos OS Network Interfaces Configuration Guide.
MPLS Applications
In the Junos OS implementation of MPLS, establishing an LSP installs on the ingress
router a host route (a 32-bit mask) toward the egress router. The address of the host
route is the destination address of the LSP. By default, the route has a preference value
of 7, a value that is higher than all routes except direct interface and static routes. The
32-bit mask ensures that the route is more specific (that is, a longer match) than all other
subnet routes. The host routes can be used to traffic-engineer BGP destinations only, or
both IGP and BGP destinations.
This section discusses the following topics:
•
BGP Destinations on page 42
•
IGP and BGP Destinations on page 44
•
Selecting a Forwarding LSP Next Hop on page 44
BGP Destinations
You can configure MPLS to control the paths that traffic takes to destinations outside
an AS.
Both IBGP and EBGP take advantage of the LSP host routes without requiring extra
configuration. BGP compares the BGP next-hop address with the LSP host route. If a
match is found, the packets for the BGP route are label-switched over the LSP. If multiple
BGP routes share the same next-hop address, all the BGP routes are mapped to the
same LSP route, regardless of which BGP peer the routes are learned from. If the BGP
next-hop address does not match an LSP host route, BGP routes continue to be forwarded
based on the IGP routes within the routing domain. In general, when both an LSP route
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and an IGP route exist for the same BGP next-hop address, the one with the lowest
preference is chosen.
Figure 11 on page 43 shows an MPLS topology that illustrates how MPLS and LSPs work.
This topology consists of a single domain with four routers. The two routers at the edges
of the domain, Router 1 and Router 4, are running EBGP to communicate with peers
outside the domain and IBGP to communicate between themselves. For intradomain
communication, all four routers are running an IGP. Finally, an LSP tunnel exists from
Router 1 to Router 4.
Figure 11: MPLS Application Topology
When BGP on Router 1 receives prefixes from Router 4, it must determine how to reach
a BGP next-hop address. Typically, when traffic engineering is not enabled, BGP uses
IGP routes to determine how to reach next-hop addresses. (See the left side of Figure 12
on page 44.) However, when traffic engineering is enabled, if the BGP next-hop matches
the LSP tunnel endpoint (that is, the MPLS egress router), those prefixes enter the LSP
tunnel. (To track these prefixes, look at the Active Route field in the show mpls lsp
command output or at the output of the show route label-switched-path path-name
command.) If the BGP next hop does not match an LSP tunnel endpoint, those prefixes
are sent following the IGP’s shortest path. (See Figure 12 on page 44.)
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Figure 12: How BGP Determines How to Reach Next-Hop Addresses
IGP and BGP Destinations
You can configure MPLS to control the paths that traffic takes to destinations within an
AS.
When traffic engineering is for BGP destinations only, the MPLS host routes are installed
in the inet.3 routing table (see Figure 13 on page 45), separate from the routes learned
from other routing protocols. Not all inet.3 routes are downloaded into the forwarding
table. Packets directly addressed to the egress router do not follow the LSP, which
prevents routes learned from LSPs from overriding routes learned from IGPs or other
sources.
Traffic within a domain, including BGP control traffic between BGP peers, is not affected
by LSPs. MPLS affects interdomain traffic only; that is, it affects only those BGP prefixes
that are learned from an external domain. MPLS does not disrupt intradomain traffic, so
IS-IS or OSPF routes remain undisturbed. If you issue a ping or traceroute command to
any destination within the domain, the ping or traceroute packets follow the IGP path.
However, if you issue a ping or traceroute command from Router 1 in Figure 11 on page 43
(the LSP ingress router) to a destination outside of the domain, the packets use the LSP
tunnel.
When traffic engineering for IGP and BGP destinations is enabled, the MPLS host routes
are installed in the inet.0 table (see Figure 14 on page 46) and downloaded into the
forwarding table. Any traffic destined to the egress router could enter the LSP. In effect,
it moves all the routes in inet.3 into inet.0, causing the inet.3 table to be emptied.
RSVP packets automatically avoid all MPLS LSPs, including those established by RSVP
or LDP. This prevents placing one RSVP session into another LSP, or in other words,
nesting one LSP into another.
Selecting a Forwarding LSP Next Hop
If more than one LSP tunnel to a BGP next hop exists, the prefixes learned from the BGP
next hop are randomly divided among the LSP tunnels. To control which LSP BGP uses
to forward data for a given prefix, use the install-nexthop statement in the export policy
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applied to the forwarding table. For more information, see the Junos OS Routing Protocols
Configuration Guide.
MPLS and Routing Tables
The IGPs and BGP store their routing information in the inet.0 routing table, the main IP
routing table. If the traffic-engineering bgp command is configured, thereby allowing only
BGP to use MPLS paths for forwarding traffic, MPLS path information is stored in a
separate routing table, inet.3. Only BGP accesses the inet.3 routing table. BGP uses both
inet.0 and inet.3 to resolve next-hop addresses. If the traffic-engineering bgp-igp command
is configured, thereby allowing the IGPs to use MPLS paths for forwarding traffic, MPLS
path information is stored in the inet.0 routing table. (Figure 13 on page 45 and Figure 14
on page 46 illustrate the routing tables in the two traffic engineering configurations.)
Figure 13: Routing and Forwarding Tables, traffic-engineering bgp
The inet.3 routing table contains the host address of each LSP’s egress router. This routing
table is used on ingress routers to route packets to the destination egress router. BGP
uses the inet.3 routing table on the ingress router to help in resolving next-hop addresses.
MPLS also maintains an MPLS path routing table (mpls.0), which contains a list of the
next label-switched router in each LSP. This routing table is used on transit routers to
route packets to the next router along an LSP.
Typically, the egress router in an LSP does not consult the mpls.0 routing table. (This
router does not need to consult mpls.0 because the penultimate router in the LSP either
changes the packet’s label to a value of 0 or pops the label.) In either case, the egress
router forwards it as an IPv4 packet, consulting the IP routing table, inet.0, to determine
how to forward the packet.
When a transit or egress router receives an MPLS packet, information in the MPLS
forwarding table is used to determine the next transit router in the LSP or to determine
that this router is the egress router.
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When BGP resolves a next-hop prefix, it examines both the inet.0 and inet.3 routing tables,
seeking the next hop with the lowest preference. If it finds a next-hop entry with an equal
preference in both routing tables, BGP prefers the entry in the inet.3 routing table.
Figure 14: Routing and Forwarding Tables, traffic-engineering bgp-igp
Generally, BGP selects next-hop entries in the inet.3 routing table because their
preferences are always lower than OSPF and IS-IS next-hop preferences. When you
configure LSPs, you can override the default preference for MPLS LSPs, which might
alter the next-hop selection process.
When BGP selects a next-hop entry from the inet.3 routing table, it installs that LSP into
the forwarding table in the Packet Forwarding Engine, which causes packets destined
for that next hop to enter and travel along the LSP. If the LSP is removed or fails, the path
is removed from the inet.3 routing table and from the forwarding table, and BGP reverts
to using a next hop from the inet.0 routing table.
MPLS and Traffic Protection
Typically, when an LSP fails, the router immediately upstream from the failure signals
the outage to the ingress router. The ingress router calculates a new path to the egress
router, establishes the new LSP, and then directs the traffic from the failed path to the
new path. This rerouting process can be time-consuming and prone to failure. For example,
the outage signals to the ingress router might get lost, or the new path might take too
long to come up, resulting in significant packet drops. The Junos OS provides several
complementary mechanisms for protecting against LSP failures:
•
46
Standby secondary paths—You can configure primary and secondary paths. You
configure secondary paths with the standby statement. To activate traffic protection,
you need to configure these standby paths only on the ingress router. If the primary
path fails, the ingress router immediately reroutes traffic from the failed path to the
standby path, thereby eliminating the need to calculate a new route and signal a new
path. For information about configuring standby LSPs, see “Configuring Hot Standby
of Secondary Paths” on page 166.
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•
Fast reroute—You configure fast reroute on an LSP to minimize the effect of a failure
in the LSP. Fast reroute enables a router upstream from the failure to route around the
failure quickly to the router downstream of the failure. The upstream router then signals
the outage to the ingress router, thereby maintaining connectivity before a new LSP is
established. For a detailed overview of fast reroute, see “Fast Reroute Overview” on
page 47. For information about configuring fast reroute, see “Configuring Fast Reroute”
on page 134.
•
Link protection—You can configure link protection to help ensure that traffic traversing
a specific interface from one router to another can continue to reach its destination in
the event that this interface fails. When link protection is configured for an interface
and configured for an LSP that traverses this interface, a bypass LSP is created that
handles this traffic if the interface fails. The bypass LSP uses a different interface and
path to reach the same destination. For information about configuring link protection,
see “Configuring Link Protection on Interfaces Used by LSPs” on page 366.
When standby secondary path, and fast reroute or link protection are configured on an
LSP, full traffic protection is enabled. When a failure occurs in an LSP, the router upstream
from the failure routes traffic around the failure and notifies the ingress router of the
failure. This rerouting keeps the traffic flowing while waiting for the notification to be
processed at the ingress router. After receiving the failure notification, the ingress router
immediately reroutes the traffic from the patched primary path to the more optimal
standby path.
Fast reroute and link protection provide a similar type of traffic protection. Both features
provide a quick transfer service and employ a similar design. Fast reroute and link
protection are both described in RFC 4090, Fast Reroute Extensions to RSVP-TE for LSP
Tunnels. However, you need to configure only one or the other. Although you can configure
both, there is little, if any, benefit in doing so.
Fast Reroute
The following sections provide an overview of how fast reroute works:
•
Fast Reroute Overview on page 47
•
Detour Merging Process on page 49
•
Detour Computations on page 50
•
Fast Reroute Path Optimization on page 51
Fast Reroute Overview
Fast reroute provides redundancy for an LSP path. When you enable fast reroute, detours
are precomputed and preestablished along the LSP. In case of a network failure on the
current LSP path, traffic is quickly routed to one of the detours. Figure 15 on page 48
illustrates an LSP from Router A to Router F, showing the established detours. Each
detour is established by an upstream node to avoid the link toward the immediate
downstream node and the immediate downstream node itself. Each detour might traverse
through one or more label-switched routers that are not shown in the figure.
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Fast reroute protects traffic against any single point of failure between the ingress and
egress routers. If there are multiple failures along an LSP, fast reroute itself might fail.
Also, fast reroute does not protect against failure of the ingress or egress routers.
Figure 15: Detours Established for an LSP Using Fast Reroute
If a node detects that a downstream link has failed (using a link-layer-specific liveness
detection mechanism) or that a downstream node has failed (for example, using the
RSVP neighbor hello protocol), the node quickly switches the traffic to the detour and,
at the same time, signals the ingress router about the link or node failure. Figure 16 on
page 48 illustrates the detour taken when the link between Router B and Router C fails.
Figure 16: Detour After the Link from Router B to Router C Fails
If the network topology is not rich enough (there are not enough routers with sufficient
links to other routers), some of the detours might not succeed. For example, the detour
from Router A to Router C in Figure 15 on page 48 cannot traverse link A-B and Router B.
If such a path is not possible, the detour does not occur.
Note that after the node switches traffic to the detour, it might switch the traffic again
to a newly calculated detour soon after. This is because the initial detour route might not
be the best route. To make rerouting as fast as possible, the node switches traffic onto
the initial detour without first verifying that the detour is valid. Once the switch is made,
the node recomputes the detour. If the node determines that the initial detour is still
valid, traffic continues to flow over this detour. If the node determines that the initial
detour is no longer valid, it again switches the traffic to a newly computed detour.
NOTE: If you issue show commands after the node has switched traffic to
the initial detour, the node might indicate that the traffic is still flowing over
the original LSP. This situation is temporary and should correct itself quickly.
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The time required for a fast-rerouting detour to take effect depends on two independent
time intervals:
•
Amount of time to detect that there is a link or node failure—This interval depends
greatly on the link layer in use and the nature of the failure. For example, failure detection
on an SONET/SDH link typically is much faster than on a Gigabit Ethernet link, and
both are much faster than detection of a router failure.
•
Amount of time required to splice the traffic onto the detour—This operation is
performed by the Packet Forwarding Engine, which requires little time to splice traffic
onto the detour. The time needed can vary depending on the number of LSPs being
switched to detours.
Fast reroute is a short-term patch to reduce packet loss. Because detour computation
might not reserve adequate bandwidth, the detours might introduce congestion on the
alternate links. The ingress router is the only router that is fully aware of LSP policy
constraints and, therefore, is the only router able to come up with adequate long-term
alternate paths.
Detours are created by use of RSVP and, like all RSVP sessions, they require extra state
and overhead in the network. For this reason, each node establishes at most one detour
for each LSP that has fast reroute enabled. Creating more than one detour for each LSP
increases the overhead, but serves no practical purpose.
To reduce network overhead further, each detour attempts to merge back into the LSP
as soon as possible after the failed node or link. If you can consider an LSP that travels
through n router nodes, it is possible to create n – 1 detours. For instance, in Figure 17 on
page 49, the detour tries to merge back into the LSP at Router D instead of at Router E
or Router F. Merging back into the LSP makes the detour scalability problem more
manageable. If topology limitations prevent the detour from quickly merging back into
the LSP, detours merge with other detours automatically.
Figure 17: Detours Merging into Other Detours
Detour Merging Process
This section describes the process used by a router to determine which LSP to select
when the router receives path messages from different interfaces with identical Session
and Sender Template objects. When this occurs, the router needs to merge the path
states.
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The router employs the following process to determine when and how to merge path
states:
•
When all the path messages do not include a fast reroute or a detour object, or when
the router is the egress of the LSP, no merging is required. The messages are processed
according to RSVP traffic engineering.
•
Otherwise, the router must record the path state in addition to the incoming interface.
If the path messages do not share the same outgoing interface and next-hop router,
the router considers them to be independent LSPs and does not merge them.
•
For all the path messages that share the same outgoing interface and next-hop router,
the router uses the following process to select the final LSP:
•
•
If only one LSP originates from this node, select it as the final LSP.
•
If only one LSP contains a fast reroute object, select it as the final LSP.
•
If there are several LSPs and some of them have a detour object, eliminate those
containing a detour object from the final LSP selection process.
•
If several final LSP candidates remain (that is, there are still both detour and protected
LSPs), select the LSPs with fast reroute objects.
•
If none of the LSPs have fast reroute objects, select the ones without detour objects.
If all the LSPs have detour objects, select them all.
•
Of the remaining LSP candidates, eliminate from consideration those that traverse
nodes that other LSPs avoid.
•
If several candidate LSPs still remain, select the one with the shortest explicit route
object (ERO) path length. If more than one LSP has the same path length, select
one randomly.
Once the final LSP has been identified, the router must transmit only the path messages
that correspond to this LSP. All other LSPs are considered merged at this node.
Detour Computations
Computing and setting up detours is done independently at each node. On a node, if an
LSP has fast reroute enabled and if a downstream link or node can be identified, the
router performs a Constrained Shortest Path First (CSPF) computation using the
information in the local traffic engineering database. For this reason, detours rely on your
IGP supporting traffic engineering extensions. Without the traffic engineering database,
detours cannot be established.
CSPF initially attempts to find a path that skips the next downstream node. Attempting
to find this path provides protection against downstream failures in either nodes or links.
If a node-skipping path is not available, CSPF attempts to find a path on an alternate
link to the next downstream node. Attempting to find an alternate link provides protection
against downstream failures in links only. Detour computations might not succeed the
first time. If a computation fails, the router recomputes detours approximately once every
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refresh interval until the computation succeeds. The RSVP metric for each detour is set
to a value in the range from 10,000 through 19,999.
Fast Reroute Path Optimization
A fast reroute protection path is nondeterministic. The actual protection path of a
particular node depends on the history of the LSP and the network topology when the
fast reroute path was computed. The lack of deterministic behavior can lead to operational
difficulties and poorly optimized paths after multiple link flaps in a network. Even in a
small network, after a few link flaps fast reroute paths can traverse an arbitrarily large
number of nodes and can remain in that state indefinitely. This is inefficient and makes
the network less predictable.
Fast reroute optimization addresses this deficiency. It provides a global path optimization
timer, allowing you to optimize all LSPs that have fast reroute enabled and a detour path
up and running. The timer value can be varied depending on the expected RE processing
load.
The fast reroute optimization algorithm is based on the IGP metric only. As long as the
new path’s IGP metric is lower than the old path’s, the CSPF result is accepted, even if
the new path might be more congested (higher bandwidth utilization) or traverses more
hops.
In conformance with RFC 4090, Fast Reroute Extensions to RSVP-TE for LSP Tunnels,
when a new path is computed and accepted for fast reroute optimization, the existing
detour is destroyed first and then the new detour is established. To prevent traffic loss,
detours actively protecting traffic are not optimized.
Automatic Bandwidth Allocation
Automatic bandwidth allocation allows an MPLS tunnel to automatically adjust its
bandwidth allocation based on the volume of traffic flowing through the tunnel. You can
configure an LSP with minimal bandwidth; this feature can dynamically adjust the LSP’s
bandwidth allocation based on current traffic patterns. The bandwidth adjustments do
not interrupt traffic flow through the tunnel.
You set a sampling interval on an LSP configured with automatic bandwidth allocation.
The average bandwidth is monitored during this interval. At the end of the interval, an
attempt is made to signal a new path for the LSP with the bandwidth allocation set to
the maximum average value for the preceding sampling interval. If the new path is
successfully established and the original path is removed, the LSP is switched over to
the new path. If a new path is not created, the LSP continues to use its current path until
the end of the next sampling interval, when another attempt is made to establish a new
path. Note that you can set minimum and maximum bandwidth values for the LSP.
During the automatic bandwidth allocation interval, the router might receive a steady
increase in traffic (increasing bandwidth utilization) on an LSP, potentially causing
congestion or packet loss. To prevent this, you can define a second trigger to prematurely
expire the automatic bandwidth adjustment timer before the end of the current
adjustment interval.
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Point-to-Multipoint LSPs Overview
A point-to-multipoint MPLS LSP is an LSP with a single source and multiple destinations.
By taking advantage of the MPLS packet replication capability of the network,
point-to-multipoint LSPs avoid unnecessary packet replication at the ingress router.
Packet replication takes place only when packets are forwarded to two or more different
destinations requiring different network paths.
This process is illustrated in Figure 18 on page 52. Router PE1 is configured with a
point-to-multipoint LSP to Routers PE2, PE3, and PE4. When Router PE1 sends a packet
on the point-to-multipoint LSP to Routers P1 and P2, Router P1 replicates the packet and
forwards it to Routers PE2 and PE3. Router P2 sends the packet to Router PE4.
This feature is described in detail in the Internet drafts
draft-raggarwa-mpls-p2mp-te-02.txt (expired February 2004), Establishing Point to
Multipoint MPLS TE LSPs, draft-ietf-mpls-rsvp-te-p2mp-02.txt, Extensions to Resource
Reservation Protocol-Traffic Engineering (RSVP-TE) for Point-to-Multipoint TE
Label-Switched Paths (LSPs), and draft-ietf-mpls-ldp-p2mp-10.txt, Label Distribution
Protocol Extensions for Point-to-Multipoint and Multipoint-to-Multipoint Label Switched
Paths.
Figure 18: Point-to-Multipoint LSPs
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The following are some of the properties of point-to-multipoint LSPs:
Related
Documentation
•
A point-to-multipoint LSP enables you to use MPLS for point-to-multipoint data
distribution. This functionality is similar to that provided by IP multicast.
•
You can add and remove branch LSPs from a main point-to-multipoint LSP without
disrupting traffic. The unaffected parts of the point-to-multipoint LSP continue to
function normally.
•
You can configure a node to be both a transit and an egress router for different branch
LSPs of the same point-to-multipoint LSP.
•
You can enable link protection on a point-to-multipoint LSP. Link protection can provide
a bypass LSP for each of the branch LSPs that make up the point-to-multipoint LSP.
If any of the primary paths fail, traffic can be quickly switched to the bypass.
•
You can configure branch LSPs either statically, dynamically, or as a combination of
static and dynamic LSPs.
•
You can enable graceful Routing Engine switchover (GRES) and graceful restart for
point-to-multipoint LSPs at ingress and egress routers. The point-to-multipoint LSPs
must be configured using either static routes or circuit cross-connect (CCC). GRES and
graceful restart allow the traffic to be forwarded at the Packet Forwarding Engine
based on the old state while the control plane recovers. Feature parity for GRES and
graceful restart for MPLS point-to-multipoint LSPs on the Junos Trio chipset is
supported in Junos OS Releases 11.1R2, 11.2R2, and 11.4.
•
Junos OS High Availability Configuration Guide
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CHAPTER 4
MPLS Router Configuration Guidelines
This chapter discusses the following topics:
•
Minimum MPLS Configuration on page 55
•
Configuring the Ingress Router for MPLS-Signaled LSPs on page 56
•
Example: Configuring a Constrained-Path LSP for Which Junos OS Makes All Forwarding
Decisions on page 60
•
Example: Configuring an Explicit-Path LSP on page 61
•
Example: Configuring a Constrained-Path LSP for Which Junos OS Makes Most
Forwarding Decisions and Considers Hop Constraints on page 62
•
Example: Configuring a Constrained-Path LSP for Which Junos OS Makes Most
Forwarding Decisions and the Secondary Path Is Explicit on page 62
•
Configuring the Intermediate and Egress Routers for MPLS-Signaled LSPs on page 63
•
Improving Traffic Engineering Database Accuracy with RSVP PathErr
Messages on page 63
•
Configuring MPLS-Signaled LSPs to Use GRE Tunnels on page 66
•
Tunneling IPv6 Traffic over MPLS IPv4 Networks on page 67
•
Configuring ICMP Message Tunneling for MPLS on page 71
•
Example: Configuring SRLG on page 71
•
Example: Excluding SRLG Links Completely for the Secondary LSP on page 80
•
Example: Configuring SRLG With Link Protection on page 85
•
Example: Configuring SRLG With Link Protection With the exclude-srlg
Option on page 105
Minimum MPLS Configuration
To enable MPLS on the router, you must include at least the following statements. This
minimum configuration enables MPLS on a logical interface. All other MPLS configuration
statements are optional. Note that this configuration does nothing more than enable
MPLS on the router and on the specified interface.
Include the family mpls statement:
family mpls;
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You can include this statement at the following hierarchy levels:
•
[edit interfaces interface-name unit logical-unit-number]
•
[edit logical-systems logical-system-name interfaces interface-name unit
logical-unit-number]
Include the interface in the MPLS and RSVP protocol configuration:
mpls {
interface (interface-name | all); # Required to enable MPLS on the interface
}
rsvp { # Required for RSVP-signaled MPLS only
interface interface-name;
}
You can configure these statements at the following hierarchy levels:
•
[edit protocols]
•
[edit logical-systems logical-system-name protocols]
For every interface you enable, two special routes are installed automatically in the MPLS
forwarding table. One route has a label value of 0, and the second has a label value of
1. (For information about these labels, see “Special Labels” on page 28.)
Configuring the Ingress Router for MPLS-Signaled LSPs
MPLS-signaled label-switched paths (LSPs) run from a specific ingress router to a specific
egress router. For basic MPLS-signaled LSP function, you must configure the ingress
router, but do not have to configure any other routers.
To configure signaled LSPs, perform the following tasks on the ingress router:
•
Creating Named Paths on page 56
•
Configuring Alternate Backup Paths Using Fate Sharing on page 58
Creating Named Paths
To configure signaled LSPs, you must first create one or more named paths on the ingress
router. For each path, you can specify some or all transit routers in the path, or you can
leave it empty.
Each pathname can contain up to 32 characters and can include letters, digits, periods,
and hyphens. The name must be unique within the ingress router. Once a named path is
created, you can use the named path with the primary or secondary statement to configure
LSPs at the [edit protocols mpls label-switched-path label-path-name] hierarchy level.
You can specify the same named path on any number of LSPs.
To determine whether an LSP is associated with the primary or secondary path in an
RSVP session, issue the show rsvp session detail command. For more information, see
the Junos OS Routing Protocols and Policies Command Reference.
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To create an empty path, create a named path by including the following form of the
path statement. This form of the path statement is empty, which means that any path
between the ingress and egress routers is accepted. In actuality, the path used tends to
be the same path as is followed by destination-based, best-effort traffic.
path path-name;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls]
To create a path in which you specify some or all transit routers in the path, include the
following form of the path statement, specifying one address for each transit router:
path path-name {
(address | hostname) <strict | loose>;
}
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls]
In this form of the path statement, you specify one or more transit router addresses.
Specifying the ingress or egress routers is optional. You can specify the address or
hostname of each transit router, although you do not need to list each transit router if its
type is loose. Specify the addresses in order, starting with the ingress router (optional)
or the first transit router, and continuing sequentially along the path up to the egress
router (optional) or the router immediately before the egress router. You need to specify
only one address per router hop. If you specify more than one address for the same router,
only the first address is used; the additional addresses are ignored and truncated.
For each router address, you specify the type, which can be one of the following:
•
strict—(Default) The route taken from the previous router to this router is a direct path
and cannot include any other routers. If address is an interface address, this router also
ensures that the incoming interface is the one specified. Ensuring that the incoming
interface is the one specified is important when there are parallel links between the
previous router and this router. It also ensures that routing can be enforced on a per-link
basis.
For strict addresses, you must ensure that the router immediately preceding the router
you are configuring has a direct connection to that router. The address can be a loopback
interface address, in which case the incoming interface is not checked.
•
loose—The route taken from the previous router to this router need not be a direct path,
can include other routers, and can be received on any interface. The address can be
any interface address or the address of the loopback interface.
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Examples: Creating Named Paths
Configure a path, to-hastings, to specify the complete strict path from the ingress to the
egress routers through 14.1.1.1, 13.1.1.1, 12.1.1.1, and 11.1.1.1, in that order. There cannot be any
intermediate routers except the ones specified. However, there can be intermediate
routers between 11.1.1.1 and the egress router because the egress router is not specifically
listed in the path statement. To prevent intermediate routers before egress, configure
the egress router as the last router, with a strict type.
[edit protocols mpls]
path to-hastings {
14.1.1.1 strict;
13.1.1.1 strict;
12.1.1.1 strict;
11.1.1.1 strict;
}
Create a path, alt-hastings, to allow any number of intermediate routers between routers
14.1.1.1 and 11.1.1.1. In addition, intermediate routers are permitted between 11.1.1.1 and the
egress router.
[edit protocols mpls]
path alt-hastings {
14.1.1.1 strict;
11.1.1.1 loose;
}
Configuring Alternate Backup Paths Using Fate Sharing
You can create a database of information that Constrained Shortest Path First (CSPF)
uses to compute one or more backup paths in case the primary path becomes unstable.
The database describes the relationships between elements of the network, such as
routers and links. Because these network elements share the same fate, this relationship
is called fate sharing.
You can configure backup paths that minimize the number of shared links and fiber paths
with the primary paths as much as possible to ensure that, if a fiber is cut, the minimum
amount of data is lost and a path still exists to the destination.
For a backup path to work optimally, it must not share links or physical fiber paths with
the primary path. This ensures that a single point of failure will not affect the primary
and backup paths at the same time.
The following sections describe how to configure fate sharing and how it affects CSPF,
and provides a fate sharing configuration example:
•
Configuring Fate Sharing on page 58
•
Implications for CSPF on page 60
•
Example: Configuring Fate Sharing on page 60
Configuring Fate Sharing
To configure fate sharing, include the fate-sharing statement:
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fate-sharing {
group group-name {
cost value;
from address <to address>;
}
}
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
Each fate-sharing group must have a name, which can be up to 32 characters long and
can contain letters, digits, periods (.) and hyphens (-). You can define up to 512 groups.
Fate-sharing groups contain three types of objects:
•
Point-to-point links—Identified by the IP addresses at each end of the link. Unnumbered
point-to-point links are typically identified by borrowing IP addresses from other
interfaces. Order is not important; from 1.2.3.4 to 1.2.3.5 and from 1.2.3.5 to 1.2.3.4 have
the same meaning.
•
Non-point-to-point links—Include links on a LAN interface (such as Gigabit Ethernet
interfaces) or nonbroadcast multiaccess (NBMA) interfaces (such as Asynchronous
Transfer Mode [ATM] or Frame Relay). You identify these links by their individual
interface address. For example, if the LAN interface 192.168.200.0/24 has four routers
attached to it, each router link is individually identified:
from 192.168.200.1; # LAN interface of router 1
from 192.168.200.2; # LAN interface of router 2
from 192.168.200.3; # LAN interface of router 3
from 192.168.200.4; # LAN interface of router 4
You can list the addresses in any order.
•
A router node—Identified by its configured router ID.
All objects in a group share certain similarities. For example, you can define a group for
all fibers that share the same fiber conduit, all optical channels that share the same fiber,
all links that connect to the same LAN switch, all equipment that shares the same power
source, and so on. All objects are treated as /32 host addresses.
For a group to be meaningful, it should contain at least two objects. You can configure
groups with zero or one object; these groups are ignored during processing.
An object can be in any number of groups, and a group can contain any number of objects.
Each group has a configurable cost attributed to it, which represents the level of impact
this group has on CSPF computations. The higher the cost, the less likely a backup path
will share with the primary path any objects in the group. The cost is directly comparable
to traffic engineering metrics. By default, the cost is 1. Changing the fate-sharing database
does not affect established LSPs until the next reoptimization of CSPF. The fate-sharing
database does influence fast-reroute computations.
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Implications for CSPF
When CSPF computes the primary paths of an LSP (or secondary paths when the primary
path is not active), it ignores the fate-sharing information. You always want to find the
best possible path (least IGP cost) for the primary path.
When CSPF computes a secondary path while the primary path (of the same LSP) is
active, the following occurs:
1.
CSPF identifies all fate-sharing groups that are associated with the primary path.
CSPF does this by identifying all links and nodes that the primary path traverses and
compiling group lists that contain at least one of the links or nodes. CSPF ignores the
ingress and egress nodes in the search.
2. CSPF checks each link in the traffic engineering database against the compiled group
list. If the link is a member of a group, the cost of the link is increased by the cost of
the group. If a link is a member of multiple groups, all group costs are added together.
3. CSPF performs the check for every node in the traffic engineering database, except
the ingress and egress node. Again, a node can belong to multiple groups, so costs
are additive.
4. The router performs regular CSPF computation with the adjusted topology.
Example: Configuring Fate Sharing
Configure fate-sharing groups east and west. Because west has no objects, it is ignored
during processing.
[edit routing-options]
fate-sharing {
group east {
cost 20; # Optional, default value is 1
from 1.2.3.4 to 1.2.3.5; # A point-to-point link
from 192.168.200.1; # LAN interface
from 192.168.200.2; # LAN interface
from 192.168.200.3; # LAN interface
from 192.168.200.4; # LAN interface
from 10.168.1.220; # Router ID of a router node
from 10.168.1.221; # Router ID of a router node
}
group west {
.....
}
}
Example: Configuring a Constrained-Path LSP for Which Junos OS Makes All Forwarding
Decisions
On the ingress router, create a constrained-path LSP in which the Junos OS makes all
the forwarding decisions. When the LSP is successfully set up, a route toward 10.1.1.1/32
is installed in the inet.3 table so that all BGP routes with matching BGP next-hop addresses
can be forwarded through the LSP.
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[edit]
interfaces {
so-0/0/0 {
unit 0 {
family mpls;
}
}
}
protocols {
rsvp {
interface so-0/0/0;
}
mpls {
label-switched-path to-hastings {
to 10.1.1.1;
}
interface so-0/0/0;
}
}
Example: Configuring an Explicit-Path LSP
On the ingress router, create an explicit-path LSP, and specify the transit routers between
the ingress and egress routers. In this configuration, no constrained-path computation
is performed. For the primary path, all intermediate hops are strictly specified so that its
route cannot change. The secondary path must travel through router 14.1.1.1 first, then
take whatever route is available to reach the destination. The remaining route taken by
the secondary path is typically the shortest path computed by the IGP.
[edit]
interfaces {
so-0/0/0 {
unit 0 {
family mpls;
}
}
}
protocols {
rsvp {
interface so-0/0/0;
}
mpls {
path to-hastings {
14.1.1.1 strict;
13.1.1.1 strict;
12.1.1.1 strict;
11.1.1.1 strict;
}
path alt-hastings {
14.1.1.1 strict;
11.1.1.1 loose; # Any IGP route is acceptable
}
label-switched-path hastings {
to 11.1.1.1;
hop-limit 32;
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bandwidth 10m; # Reserve 10 Mbps
no-cspf; # do not perform constrained-path computation
primary to-hastings;
secondary alt-hastings;
}
interface so-0/0/0;
}
}
Example: Configuring a Constrained-Path LSP for Which Junos OS Makes Most
Forwarding Decisions and Considers Hop Constraints
On the ingress router, create a constrained-path LSP in which the Junos OS makes most
of the forwarding decisions, taking into account the hop constraints listed in the path
statements. The LSP is adaptive so that no bandwidth double-counting occurs on links
shared by primary and secondary paths. To acquire the necessary link bandwidth, this
LSP is allowed to preempt lower priority sessions. Finally, this path always keeps the
secondary path in hot-standby state for quick failover.
[edit protocols]
mpls {
path to-hastings {
14.1.1.1 loose;
}
path alt-hastings {
12.1.1.1 loose;
11.1.1.1 strict;
}
label-switched-path hastings {
to 11.1.1.1;
bandwidth 10m; # Reserve 10 Mbps
priority 0 0; # Preemptive, but not preemptable
adaptive; # Set adaptivity
primary to-hastings;
secondary alt-hastings {
standby;
bandwidth 1m; # Reserve only 1 Mbps for the secondary path
}
}
interface all;
}
Example: Configuring a Constrained-Path LSP for Which Junos OS Makes Most
Forwarding Decisions and the Secondary Path Is Explicit
On the ingress router, create a constrained-path LSP in which the Junos OS makes most
of the forwarding decisions for the primary path, subject to constraints of the path
to-hastings, and in which the secondary path is an explicit path. The primary path must
transit green or yellow links and must stay away from red links. The primary path is
periodically recomputed and reoptimized. Finally, this path always keeps the secondary
path in hot-standby state for quick failover.
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When the LSP is up—either because the primary or secondary path is up, or because both
paths are up—the prefix 16.0.0.0/8 is installed in the inet.3 table so that all BGP routes
whose BGP next hop falls within that range can use the LSP. Also, the prefix 17/8 is
installed in the inet.0 table so that BGP can resolve only its next hop through that prefix.
The route also can be reached with the traceroute or ping command. These two routes
are in addition to the 11.1.1.1/32 route.
[edit protocols]
mpls {
admin-groups {
green 1;
yellow 2;
red 3;
}
path to-hastings {
14.1.1.1 loose;
}
path alt-hastings {
14.1.1.1 strict;
13.1.1.1 strict;
12.1.1.1 strict;
11.1.1.1 strict;
}
label-switched-path hastings {
to 11.1.1.1;
bandwidth 100m;
install 16.0.0.0/8; # in inet.3; cannot use to traceroute or ping
install 17.0.0.0/8 active; # installed in inet.0; can use to traceroute or ping
primary to-hastings {
admin-group { # further constraints for path computation
include-all [ green yellow ];
exclude red;
}
optimize-timer 3600; # reoptimize every hour
}
secondary alt-hastings {
standby;
no-cspf; # do not perform constrained-path computation
}
}
interface all;
Configuring the Intermediate and Egress Routers for MPLS-Signaled LSPs
To configure signaled LSPs on all MPLS routers that should participate in MPLS, you
need to enable MPLS and RSVP on these routers, as described in “Minimum MPLS
Configuration” on page 55 and “Minimum RSVP Configuration” on page 355.
Improving Traffic Engineering Database Accuracy with RSVP PathErr Messages
An essential element of RSVP-based traffic engineering is the traffic engineering database.
The traffic engineering database contains a complete list of all network nodes and links
participating in traffic engineering, and a set of attributes each of those links can hold.
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(For more information about the traffic engineering database, see “Constrained-Path
LSP Computation” on page 32.) One of the most important link attributes is bandwidth.
Bandwidth availability on links changes quickly as RSVP LSPs are established and
terminated. It is likely that the traffic engineering database will develop inconsistencies
relative to the real network. These inconsistencies cannot be fixed by increasing the rate
of IGP updates.
Link availability can share the same inconsistency problem. A link that becomes
unavailable can break all existing RSVP LSPs. However, its unavailability might not readily
be known by the network.
When you configure the rsvp-error-hold-time statement, a source node (ingress of an
RSVP LSP) learns from the failures of its LSP by monitoring PathErr messages transmitted
from downstream nodes. Information from the PathErr messages is incorporated into
subsequent LSP computations, which can improve the accuracy and speed of LSP setup.
Some PathErr messages are also used to update traffic engineering database bandwidth
information, reducing inconsistencies between the traffic engineering database and the
network.
You can control the frequency of IGP updates by using the update-threshold statement.
See “Configuring the RSVP Update Threshold on an Interface” on page 361.
This section discusses the following topics:
•
PathErr Messages on page 64
•
Identifying the Problem Link on page 65
•
Configuring the Router to Improve Traffic Engineering Database Accuracy on page 65
PathErr Messages
PathErr messages report a wide variety of problems by means of different code and
subcode numbers. You can find a complete list of these PathErr messages in RFC 2205,
Resource Reservation Protocol (RSVP), Version 1, Functional Specification and RFC 3209,
RSVP-TE: Extensions to RSVP for LSP Tunnels.
When you configure the rsvp-error-hold-time statement, two categories of PathErr
messages, which specifically represent link failures, are examined:
•
Link bandwidth is low for this LSP: Requested bandwidth unavailable—code 1, subcode
2
This type of PathErr message represents a global problem that affects all LSPs
transiting the link. They indicate that the actual link bandwidth is lower than that
required by the LSP, and that it is likely that the bandwidth information in the traffic
engineering database is an overestimate.
When this type of error is received, the available link bandwidth is reduced in the local
traffic engineering database, affecting all future LSP computations.
•
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Link unavailable for this LSP:
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•
Admission Control failure—code 1, any subcode except 2
•
Policy Control failures—code 2
•
Service Preempted—code 12
•
Routing problem—no route available toward destination—code 24, subcode 5
These types of PathErr messages are generally pertinent to the specified LSP. The
failure of this LSP does not necessarily imply that other LSPs could also fail. These
errors can indicate maximum transfer unit (MTU) problems, service preemption (either
manually initiated by the operator or by another LSP with a higher priority), that a
next-hop link is down, that a next-hop neighbor is down, or service rejection because
of policy considerations. It is best to route this particular LSP away from the link.
Identifying the Problem Link
Each PathErr message includes the sender’s IP address. This information is propagated
unchanged toward the ingress router. A lookup in the traffic engineering database can
identify the node that originated the PathErr message.
Each PathErr message carries enough information to identify the RSVP session that
triggered the message. If this is a transit router, it simply forwards the message. If this
router is the ingress router (for this RSVP session), it has the complete list of all nodes
and links the session should traverse. Coupled with the originating node information, the
link can be uniquely identified.
Configuring the Router to Improve Traffic Engineering Database Accuracy
To improve the accuracy of the traffic engineering database, configure the
rsvp-error-hold-time statement. When this statement is configured, a source node (ingress
of an RSVP LSP) learns from the failures of its LSP by monitoring PathErr messages
transmitted from downstream nodes. Information from the PathErr messages is
incorporated into subsequent LSP computations, which can improve the accuracy and
speed of LSP setup. Some PathErr messages also are used to update traffic engineering
database bandwidth information, reducing inconsistencies between the traffic engineering
database and the network.
To configure how long MPLS should remember RSVP PathErr messages and consider
them in CSPF computation, include the rsvp-error-hold-time statement:
rsvp-error-hold-time seconds;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls]
The time can be a value from 1 to 240 seconds. The default is 25 seconds. Configuring a
value of 0 disables the monitoring of PathErr messages.
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Configuring MPLS-Signaled LSPs to Use GRE Tunnels
MPLS LSPs can use generic routing encapsulation (GRE) tunnels to cross routing areas,
autonomous systems, and ISPs. Bridging MPLS LSPs over an intervening IP domain is
possible without disrupting the outlying MPLS domain.
LSPs can reach any destination that the GRE tunnels can reach. MPLS applications can
be deployed without requiring all transit nodes to support MPLS, or requiring all transit
nodes to support the same label distribution protocols (LDP or RSVP). If you use CSPF,
you must configure OSPF or IS-IS through the GRE tunnel. Traffic engineering is not
supported over GRE tunnels; for example, you cannot reserve bandwidth or set priority
or preemption.
NOTE: Use the no-control word statement to disable the control word when
the topology uses GRE as the connection mechanism between provider edge
routers and one of the provider edge routers is an M Series Multiservice Edge
Router.
For more information about GRE tunnels, see the Junos OS Services Interfaces Configuration
Guide.
Example: Configuring MPLS-Signaled LSPs to Use GRE Tunnels
To configure MPLS over GRE tunnels:
1.
Enable family mpls under the GRE interface configuration:
[edit interfaces]
interface gr-1/2/0 {
unit 0 {
tunnel {
source 192.168.1.1;
destination 192.168.1.2;
}
family inet {
address 5.1.1.1/30;
}
family iso;
family mpls;
}
}
2. Enable RSVP and MPLS over the GRE tunnel:
[edit protocols]
rsvp {
interface gr-1/2/0.0;
}
mpls {
...
interface gr-1/2/0.0;
}
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3. Configure LSPs to travel through the GRE tunnel endpoint address:
[edit protocols]
mpls {
label-switched-path gre-tunnel {
to 5.1.1.2;
...
}
}
Standard LSP configuration options apply. If the routing table specifies that a particular
route will traverse a GRE tunnel, the RSVP packets will traverse the tunnel as well.
Tunneling IPv6 Traffic over MPLS IPv4 Networks
You can configure the Junos OS to tunnel IPv6 over an MPLS-based IPv4 network. This
configuration allows you to interconnect a number of smaller IPv6 networks over an
IPv4-based network core, giving you the ability to provide IPv6 service without having to
upgrade the routers in your core network. Multiprotocol Border Gateway Protocol
(MP-BGP) is configured to exchange routes between the IPv6 networks, and data is
tunneled between these IPv6 networks by means of IPv4-based MPLS.
In Figure 19 on page 67, Routers PE1 and PE2 are dual-stack BGP routers, meaning they
have both IPv4 and IPv6 stacks. The PE routers link the IPv6 networks through the
customer edge (CE) routers to the IPv4 core network. The CE routers and the PE routers
connect through a link layer that can carry IPv6 traffic. The PE routers use IPv6 on the
CE router-facing interfaces and use IPv4 and MPLS on the core-facing interfaces. Note
that one of the connected IPv6 networks could be the global IPv6 Internet.
Figure 19: IPv6 Networks Linked by MPLS IPv4 Tunnels
The two PE routers are linked through an MP-BGP session using IPv4 addresses. They
use the session to exchange IPv6 routes with an IPv6 (value 2) address family indicator
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Junos OS 11.4 MPLS Applications Configuration Guide
(AFI) and a subsequent AFI (SAFI) (value 4). Each PE router sets the next hop for the
IPv6 routes advertised on this session to its own IPv4 address. Because MP-BGP requires
the BGP next hop to correspond to the same address family as the network layer
reachability information (NLRI), this IPv4 address needs to be embedded within an IPv6
format.
The PE routers can learn the IPv6 routes from the CE routers connected to them using
routing protocols Routing Information Protocol next generation (RIPng) or MP-BGP, or
through static configuration. Note that if BGP is used as the PE-router-to-CE-router
protocol, the MP-BGP session between the PE router and CE router could occur over an
IPv4 or IPv6 Transmission Control Protocol (TCP) session. Also, the BGP routes exchanged
on that session would have SAFI unicast. You must configure an export policy to pass
routes between IBGP and EBGP, and between BGP and any other protocol.
The PE routers have MPLS LSPs routed to each others’ IPv4 addresses. IPv4 provides
signaling for the LSPs by means of either LDP or RSVP. These LSPs are used to resolve
the next-hop addresses of the IPv6 routes learned from MP-BGP. The next hops use
IPv4-mapped IPv6 addresses, while the LSPs use IPv4 addresses.
The PE routers always advertise IPv6 routes to each other using a label value of 2, the
explicit null label for IPv6 as defined in RFC 3032, MPLS Label Stack Encoding. As a
consequence, each of the forwarding next hops for the IPv6 routes learned from remote
PE routers normally push two labels. The inner label is 2 (this label could be different if
the advertising PE router is not a Juniper Networks routing platform), and the outer label
is the LSP label. If the LSP is a single-hop LSP, then only Label 2 is pushed.
It is also possible for the PE routers to exchange plain IPv6 routes using SAFI unicast.
However, there is one major advantage in exchanging labeled IPv6 routes. The
penultimate-hop router for an MPLS LSP can pop the outer label and then send the
packet with the inner label as an MPLS packet. Without the inner label, the
penultimate-hop router would need to discover whether the packet is an IPv4 or IPv6
packet to set the protocol field in the Layer 2 header correctly.
When the PE1 router in Figure 19 on page 67 receives an IPv6 packet from the CE1 router,
it performs a lookup in the IPv6 forwarding table. If the destination matches a prefix
learned from the CE2 router, then no labels need to be pushed and the packet is simply
sent to the CE2 router. If the destination matches a prefix that was learned from the PE2
router, then the PE1 router pushes two labels onto the packet and sends it to the provider
router. The inner label is 2 and the outer label is the LSP label for the PE2 router.
Each provider router in the service provider’s network handles the packet as it would any
MPLS packet, swapping labels as it passes from provider router to provider router. The
penultimate-hop provider router for the LSP pops the outer label and sends the packet
to the PE2 router. When the PE2 router receives the packet, it recognizes the IPv6 explicit
null label on the packet (Label 2). It pops this label and treats it as an IPv6 packet,
performing a lookup in the IPv6 forwarding table and forwarding the packet to the CE3
router.
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This section discusses the following topics:
•
IPv6 over MPLS Standards on page 69
•
Configuring IPv4 MPLS Tunnels to Carry IPv6 Traffic on page 69
IPv6 over MPLS Standards
Detailed information about the Juniper Networks implementation of IPv6 over MPLS is
described in the following Internet drafts:
•
Internet draft draft-ietf-l3vpn-bgp-ipv6-07.txt, BGP-MPLS IP VPN extension for IPv6
VPN (expires January 2006)
•
Internet draft draft-ooms-v6ops-bgp-tunnel-06.txt, Connecting IPv6 Islands over IPv4
MPLS using IPv6 Provider Edge Routers (expires July 2006)
These Internet drafts are available on the IETF website at http://www.ietf.org/.
Configuring IPv4 MPLS Tunnels to Carry IPv6 Traffic
You must perform the following tasks to allow IPv6 to be carried over an IPv4 MPLS
tunnel:
•
Configuring IPv6 on Both Core-Facing and CE Router-Facing Interfaces on page 69
•
Configuring MPLS and RSVP Between PE Routers on page 69
•
Enabling IPv6 Tunneling on PE Routers on page 70
•
Configuring Multiprotocol BGP to Carry IPv6 Traffic on page 70
Configuring IPv6 on Both Core-Facing and CE Router-Facing Interfaces
In addition to configuring the family inet6 statement on all the CE router–facing interfaces,
you must also configure the statement on all the core-facing interfaces running MPLS.
Both configurations are necessary because the router must be able to process any IPv6
packets it receives on these interfaces. You should not see any regular IPv6 traffic arrive
on these interfaces, but you will receive MPLS packets tagged with Label 2. Even though
Label 2 MPLS packets are sent in IPv4, these packets are treated as native IPv6 packets.
Include the family inet6 statement:
family inet6 {
address inet6-address;
}
You can include this statement at the following hierarchy levels:
•
[edit interfaces interface-name unit logical-unit-number]
•
[edit logical-systems logical-system-name interfaces interface-name unit
logical-unit-number]
Configuring MPLS and RSVP Between PE Routers
For information about how to configure MPLS and RSVP, see the following sections:
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•
Configuring the Ingress Router for MPLS-Signaled LSPs on page 56
•
Configuring the Intermediate and Egress Routers for MPLS-Signaled LSPs on page 63
•
Minimum RSVP Configuration on page 355
Enabling IPv6 Tunneling on PE Routers
You enable IPv6 tunneling by including the ipv6-tunneling statement in the configuration
for the PE routers. This statement allows IPv6 routes to be resolved over an MPLS network
by converting all routes stored in the inet.3 routing table to IPv4-mapped IPv6 addresses
and then copying them into the inet6.3 routing table. This routing table can be used to
resolve next hops for both inet6 and inet6-vpn routes.
NOTE: BGP automatically runs its import policy even when copying routes
from a primary routing table group to a secondary routing table group. If IPv4
labeled routes arrive from a BGP session (for example, when you have
configured the labeled-unicast statement at the [edit protocols bgp family
inet] hierarchy level on the PE router), the BGP neighbor’s import policy also
accepts IPv6 routes, since the neighbor’s import policy is run while doing the
copy operation to the inet6.3 routing table.
To configure IPv6 tunneling, include the ipv6-tunneling statement on the PE routers:
ipv6-tunneling;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls]
You also need to configure IPv6 tunneling when you configure IPv6 VPNs. For more
information, see the Junos OS VPNs Configuration Guide.
Configuring Multiprotocol BGP to Carry IPv6 Traffic
When you configure MP-BGP to carry IPv6 traffic, the IPv4 MPLS label is removed at the
destination PE router. The remaining IPv6 packet without a label can then be forwarded
to the IPv6 network. Include the explicit-null statement:
explicit-null;
You can include this statement at the following hierarchy levels:
•
[edit protocols bgp family inet6 labeled-unicast]
•
[edit protocols bgp group group-name family inet6 labeled-unicast]
•
[edit protocols bgp group group-name neighbor neighbor-name family inet6
labeled-unicast]
•
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[edit logical-systems logical-system-name protocols bgp family inet6 labeled-unicast]
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Chapter 4: MPLS Router Configuration Guidelines
•
[edit logical-systems logical-system-name protocols bgp group group-name family inet6
labeled-unicast]
•
[edit logical-systems logical-system-name protocols bgp group group-name neighbor
neighbor-name family inet6 labeled-unicast]
Configuring ICMP Message Tunneling for MPLS
Internet Control Message Protocol (ICMP) is one of the core TCP/IP protocols. Routers
can send ICMP advertisements over the network to enable hosts to discover the addresses
of operating routers. ICMP is also useful for network debugging by enabling the ping and
traceroute functions commonly used by network administrators.
ICMP message tunneling enables you to send ICMP messages over an LSP for debugging
purposes. When you configure icmp-tunneling statement at the [edit protocols mpls]
hierarchy level, ICMP messages are sent to the ingress node of a label-switched packet.
The label stack is copied from the original packet to the ICMP message packet. The ICMP
message packet can then transit the LSP across the network to the egress node, gathering
ICMP information about each router along the LSP path.
ICMP message tunneling can be useful for debugging and tracing purposes if the message
is an ICMP time exceeded message.
To configure ICMP message tunneling for MPLS, include the icmp-tunneling statement:
icmp-tunneling;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls]
Example: Configuring SRLG
This example shows how to configure Shared Link Risk Groups (SRLGs) on a device.
•
Requirements on page 71
•
Overview on page 72
•
Configuration on page 73
•
Verification on page 78
Requirements
This example uses the following hardware and software components:
•
Seven routers that can be a combination of M Series, MX Series, or T Series routers
•
Junos OS Release 11.4 or later running on all the devices
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Overview
Junos OS Release 11.4 and later support SRLG configuration in an IGP (OSPFv2 and IS-IS)
domain. In this example, you configure SRLG and associate it with the MPLS interface
on a device.
The device uses the SRLG cost parameter for the Constrained Shortest Path First (CSPF)
algorithm and tries to keep the links used for the primary and secondary paths mutually
exclusive by avoiding links that share any SRLG with the primary path.
To configure the SRLG, you first define the SRLG parameters at the [edit routing-options
srlg srlg-name] hierarchy level and then associate the SRLG with an MPLS interface at
the [edit mpls interface interface-name] hierarchy level.
The srlg srlg-name statement has the following options:
•
srlg-cost—Include a cost for the SRLG ranging from 1 through 65535. The cost of the
SRLG determines the level of impact this SRLG has on the CSPF algorithm for path
computations. The higher the cost, the less likely it is for a secondary path to share the
same SRLG as the primary path. By default, the srlg-cost is 1.
•
srlg-value—Include a group ID for the SRLG ranging from 1 through 4294967295.
In this example, PE1 is the ingress router and PE2 is the egress router. P1, P2, and P3, P4,
and P5 are transit routers. OSPF is configured on all the routers as the interior gateway
protocol (IGP). SRLG is configured on all seven routers. The primary path includes SRLG
srlg-a. For the standby secondary path, the link P2>PE2 belongs to SRLG srlg-a. The
effective link metric, with the added srlg-cost of 10, becomes 11. Therefore, the computed
secondary path is PE1>P3>P4>P5>PE2 with a CSPF link metric of 4.
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Configuration
CLI Quick
Configuration
Router PE1
To quickly configure this section of the example, copy the following commands, paste
them into a text file, remove any line breaks, change any details necessary to match your
network configuration, and then copy and paste the commands into the CLI at the [edit]
hierarchy level.
set interfaces ge-0/0/1 unit 0 family inet address 192.168.12.1/24
set interfaces ge-0/0/1 unit 0 family mpls
set interfaces ge-0/0/2 unit 0 family inet address 192.168.13.1/24
set interfaces ge-0/0/2 unit 0 family mpls
set interfaces ge-0/0/3 unit 0 family inet address 192.168.14.1/24
set interfaces ge-0/0/3 unit 0 family mpls
set interfaces lo0 unit 0 family inet address 10.255.0.1/32
set routing-options srlg srlg-a srlg-value 101
set routing-options srlg srlg-a srlg-cost 10
set protocols rsvp interface ge-0/0/1.0
set protocols rsvp interface ge-0/0/2.0
set protocols rsvp interface ge-0/0/3.0
set protocols mpls optimize-timer 120
set protocols mpls label-switched-path pe1-pe2 to 10.255.0.7
set protocols mpls label-switched-path pe1-pe2 primary via-p1
set protocols mpls label-switched-path pe1-pe2 secondary path2 standby
set protocols mpls path via-p1 10.255.0.2 strict
set protocols mpls path path2
set protocols mpls interface ge-0/0/1.0
set protocols mpls interface ge-0/0/2.0
set protocols mpls interface ge-0/0/3.0
set protocols ospf traffic-engineering
set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
set protocols ospf area 0.0.0.0 interface ge-0/0/2.0
set protocols ospf area 0.0.0.0 interface ge-0/0/3.0
set protocols ospf area 0.0.0.0 interface lo0.0
Router P1
set interfaces ge-0/0/1 unit 0 family inet address 192.168.12.2/24
set interfaces ge-0/0/1 unit 0 family mpls
set interfaces ge-0/0/2 unit 0 family inet address 192.168.27.2/24
set interfaces ge-0/0/2 unit 0 family mpls
set interfaces lo0 unit 0 family inet address 10.255.0.2/32
set routing-options srlg srlg-a srlg-value 101
set routing-options srlg srlg-a srlg-cost 10
set protocols rsvp interface ge-0/0/1.0
set protocols rsvp interface ge-0/0/2.0
set protocols mpls interface ge-0/0/1.0
set protocols mpls interface ge-0/0/2.0 srlg srlg-a
set protocols ospf traffic-engineering
set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
set protocols ospf area 0.0.0.0 interface ge-0/0/2.0
set protocols ospf area 0.0.0.0 interface lo0.0
Router P2
set interfaces ge-0/0/1 unit 0 family inet address 192.168.13.3/24
set interfaces ge-0/0/1 unit 0 family mpls
set interfaces ge-0/0/2 unit 0 family inet address 192.168.37.3/24
set interfaces ge-0/0/2 unit 0 family mpls
set interfaces lo0 unit 0 family inet address 10.255.0.3/32
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set routing-options srlg srlg-a srlg-value 101
set routing-options srlg srlg-a srlg-cost 10
set protocols rsvp interface ge-0/0/1.0
set protocols rsvp interface ge-0/0/2.0
set protocols mpls interface ge-0/0/1.0
set protocols mpls interface ge-0/0/2.0 srlg srlg-a
set protocols ospf traffic-engineering
set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
set protocols ospf area 0.0.0.0 interface ge-0/0/2.0
set protocols ospf area 0.0.0.0 interface lo0.0
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Router P3
set interfaces ge-0/0/1 unit 0 family inet address 192.168.14.4/24
set interfaces ge-0/0/1 unit 0 family mpls
set interfaces ge-0/0/2 unit 0 family inet address 192.168.45.4/24
set interfaces ge-0/0/2 unit 0 family mpls
set interfaces lo0 unit 0 family inet address 10.255.0.4/32
set routing-options srlg srlg-a srlg-value 101
set routing-options srlg srlg-a srlg-cost 10
set protocols rsvp interface ge-0/0/1.0
set protocols rsvp interface ge-0/0/2.0
set protocols mpls interface ge-0/0/1.0
set protocols mpls interface ge-0/0/2.0
set protocols ospf traffic-engineering
set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
set protocols ospf area 0.0.0.0 interface ge-0/0/2.0
set protocols ospf area 0.0.0.0 interface lo0.0
Router P4
set interfaces ge-0/0/1 unit 0 family inet address 192.168.45.5/24
set interfaces ge-0/0/1 unit 0 family mpls
set interfaces ge-0/0/2 unit 0 family inet address 192.168.56.5/24
set interfaces ge-0/0/2 unit 0 family mpls
set interfaces lo0 unit 0 family inet address 10.255.0.5/32
set routing-options srlg srlg-a srlg-value 101
set routing-options srlg srlg-a srlg-cost 10
set protocols rsvp interface ge-0/0/1.0
set protocols rsvp interface ge-0/0/2.0
set protocols mpls interface ge-0/0/1.0
set protocols mpls interface ge-0/0/2.0
set protocols ospf traffic-engineering
set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
set protocols ospf area 0.0.0.0 interface ge-0/0/2.0
set protocols ospf area 0.0.0.0 interface lo0.0
Router P5
set interfaces ge-0/0/1 unit 0 family inet address 192.168.56.6/24
set interfaces ge-0/0/1 unit 0 family mpls
set interfaces ge-0/0/2 unit 0 family inet address 192.168.67.6/24
set interfaces ge-0/0/2 unit 0 family mpls
set interfaces lo0 unit 0 family inet address 10.255.0.6/32
set routing-options srlg srlg-a srlg-value 101
set routing-options srlg srlg-a srlg-cost 10
set protocols rsvp interface ge-0/0/1.0
set protocols rsvp interface ge-0/0/2.0
set protocols mpls interface ge-0/0/1.0
set protocols mpls interface ge-0/0/2.0
set protocols ospf traffic-engineering
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Chapter 4: MPLS Router Configuration Guidelines
set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
set protocols ospf area 0.0.0.0 interface ge-0/0/2.0
set protocols ospf area 0.0.0.0 interface lo0.0
Router PE2
Step-by-Step
Procedure
set interfaces ge-0/0/1 unit 0 family inet address 192.168.27.7/24
set interfaces ge-0/0/1 unit 0 family mpls
set interfaces ge-0/0/2 unit 0 family inet address 192.168.37.7/24
set interfaces ge-0/0/2 unit 0 family mpls
set interfaces ge-0/0/3 unit 0 family inet address 192.168.67.7/24
set interfaces ge-0/0/3 unit 0 family mpls
set interfaces lo0 unit 0 family inet address 10.255.0.7/32
set routing-options srlg srlg-a srlg-value 101
set routing-options srlg srlg-a srlg-cost 10
set protocols rsvp interface ge-0/0/1.0
set protocols rsvp interface ge-0/0/2.0
set protocols rsvp interface ge-0/0/3.0
set protocols mpls interface ge-0/0/1.0
set protocols mpls interface ge-0/0/2.0
set protocols mpls interface ge-0/0/3.0
set protocols ospf traffic-engineering
set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
set protocols ospf area 0.0.0.0 interface ge-0/0/2.0
set protocols ospf area 0.0.0.0 interface ge-0/0/3.0
set protocols ospf area 0.0.0.0 interface lo0.0
The following example requires you to navigate various levels in the configuration
hierarchy. For information about navigating the CLI, see the Junos OS CLI User Guide.
To configure the ingress router PE1:
1.
Configure the device interfaces.
[edit interfaces]
user@PE1# set ge-0/0/1 unit 0 family inet address 192.168.12.1/24
user@PE1# set ge-0/0/1 unit 0 family mpls
user@PE1# set ge-0/0/2 unit 0 family inet address 192.168.13.1/24
user@PE1# set ge-0/0/2 unit 0 family mpls
user@PE1# set ge-0/0/3 unit 0 family inet address 192.168.14.1/24
user@PE1# set ge-0/0/3 unit 0 family mpls
user@PE1# set lo0 unit 0 family inet address 10.255.0.1/32
2.
Configure OSPF on the interfaces.
[edit protocols ospf]
user@PE1# set traffic-engineering
user@PE1# set area 0.0.0.0 interface ge-0/0/1.0
user@PE1# set area 0.0.0.0 interface ge-0/0/2.0
user@PE1# set area 0.0.0.0 interface ge-0/0/3.0
user@PE1# set area 0.0.0.0 interface lo0.0
3.
Configure the SRLG definitions.
[edit routing-options]
user@PE1# set routing-options srlg srlg-a srlg-value 101
user@PE1# set routing-options srlg srlg-a srlg-cost 10
4.
Configure MPLS and the LSPs.
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Junos OS 11.4 MPLS Applications Configuration Guide
[edit protocols mpls]
user@PE1# set interface ge-0/0/1.0
user@PE1# set interface ge-0/0/2.0
user@PE1# set interface ge-0/0/3.0
user@PE1# set optimize-timer 120
user@PE1# set label-switched-path pe1-pe2 to 10.255.0.7
user@PE1# set label-switched-path pe1-pe2 primary via-p1
user@PE1# set label-switched-path pe1-pe2 secondary path2 standby
user@PE1# set path via-p1 10.255.0.2 strict
user@PE1# set path path2
5.
Enable RSVP on the interfaces.
[edit protocols rsvp]
user@PE1# set interface ge-0/0/1.0
user@PE1# set interface ge-0/0/2.0
user@PE1# set interface ge-0/0/3.0
Results
From configuration mode, confirm your configuration by entering the show interfaces,
show protocols ospf, show routing-options, show protocols mpls, and show protocols rsvp
commands. If the output does not display the intended configuration, repeat the
instructions in this example to correct the configuration.
user@PE1# show interfaces
interfaces {
ge-0/0/1 {
unit 0 {
family inet {
address 192.168.12.1/24;
}
family mpls;
}
}
ge-0/0/2 {
unit 0 {
family inet {
address 192.168.13.1/24;
}
family mpls;
}
}
ge-0/0/3 {
unit 0 {
family inet {
address 192.168.14.1/24;
}
family mpls;
}
}
lo0 {
unit 0 {
family inet {
address 10.255.0.1/32;
}
}
}
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}
user@PE1# show protocols ospf
traffic-engineering;
area 0.0.0.0 {
interface ge-0/0/1.0;;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
interface lo0.0;
}
user@PE1# show protocols mpls
optimize-timer 120;
label-switched-path pe1-pe2 {
to 10.255.0.7;
primary via-p1;
secondary path2 {
standby;
}
}
path via-p1 {
10.255.0.2 strict;
}
path path2;
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
user@PE1# show protocols rsvp
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
user@PE1# show routing-options
routing-options {
srlg {
srlg-a {
srlg-value 101;
srlg-cost 10;
}
}
}
If you are done configuring the device, enter commit from configuration mode.
NOTE: Repeat this procedure for every Juniper Networks router in the IGP
domain, after modifying the appropriate interface names, addresses, and
any other parameters for each router.
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Verification
Confirm that the configuration is working properly.
•
Verifying SRLG Definitions on page 78
•
Verify TE-Link SRLG on page 78
•
Verify Standby Secondary Path on page 78
Verifying SRLG Definitions
Purpose
Action
Verify SRLG-to-value mappings and SRLG cost.
user@PE1> show mpls srlg
SRLG
srlg-a
Value
101
Cost
10
Verify TE-Link SRLG
Purpose
Action
Verify the traffic engineering link SRLG association.
user@PE1> show ted link detail
...
10.255.0.2->192.168.27.7-1, Local: 192.168.27.2, Remote: 0.0.0.0
Local interface index: 0, Remote interface index: 0
LocalPath: 1, Metric: 1, StaticBW: 1000Mbps, AvailBW: 1000Mbps
Color: 0 <none>
SRLGs: srlg-a
localBW [0] 0bps [1] 0bps [2] 0bps [3] 0bps
localBW [4] 0bps [5] 0bps [6] 0bps [7] 0bps
...
10.255.0.3->192.168.37.7-1, Local: 192.168.37.3, Remote: 0.0.0.0
Local interface index: 0, Remote interface index: 0
LocalPath: 0, Metric: 1, StaticBW: 1000Mbps, AvailBW: 1000Mbps
Color: 0 <none>
SRLGs: srlg-a
localBW [0] 0bps [1] 0bps [2] 0bps [3] 0bps
localBW [4] 0bps [5] 0bps [6] 0bps [7] 0bps
...
Meaning
Links P1-PE2 and P2-PE2 are associated with SRLG srlg-a.
Verify Standby Secondary Path
Purpose
Action
Check the SRLG link cost and its impact on the CSPF computation of the standby
secondary path link.
user@PE1> show mpls lsp ingress extensive
Ingress LSP: 1 sessions
10.255.0.7
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From: 10.255.0.1, State: Up, ActiveRoute: 0, LSPname: pe1-pe2
ActivePath: via-p1 (primary)
LSPtype: Static Configured
LoadBalance: Random
Encoding type: Packet, Switching type: Packet, GPID: IPv4
*Primary
via-p1
State: Up
Priorities: 7 0
OptimizeTimer: 120
SmartOptimizeTimer: 180
SRLG: srlg-a
Reoptimization in 110 second(s).
Computed ERO (S [L] denotes strict [loose] hops): (CSPF metric: 2)
192.168.12.2 S 192.168.27.7 S
Received RRO (ProtectionFlag 1=Available 2=InUse 4=B/W 8=Node 10=SoftPreempt
20=Node-ID):
192.168.12.2 192.168.27.7
7 Oct 13 15:17:11.310 CSPF: computation result ignored, new path no benefit
6 Oct 13 15:15:14.959 Selected as active path
5 Oct 13 15:15:14.958 Record Route: 192.168.12.2 192.168.27.7
4 Oct 13 15:15:14.954 Up
3 Oct 13 15:15:14.793 Originate Call
2 Oct 13 15:15:14.793 CSPF: computation result accepted 192.168.12.2
192.168.27.7
1 Oct 13 15:14:46.214 CSPF failed: no route toward 10.255.0.2
Standby
path2
State: Up
Priorities: 7 0
OptimizeTimer: 120
SmartOptimizeTimer: 180
Reoptimization in 115 second(s).
Computed ERO (S [L] denotes strict [loose] hops): (CSPF metric: 4)
192.168.14.4 S 192.168.45.5 S 192.168.56.6 S 192.168.67.7 S
Received RRO (ProtectionFlag 1=Available 2=InUse 4=B/W 8=Node 10=SoftPreempt
20=Node-ID):
192.168.14.4 192.168.45.5 192.168.56.6 192.168.67.7
10 Oct 13 15:17:11.929 Record Route: 192.168.14.4 192.168.45.5 192.168.56.6
192.168.67.7
9 Oct 13 15:17:11.929 Up
8 Oct 13 15:17:11.729 Originate Call
7 Oct 13 15:17:11.729 Clear Call
6 Oct 13 15:17:11.729 CSPF: computation result accepted 192.168.14.4
192.168.45.5 192.168.56.6 192.168.67.7
5 Oct 13 15:17:11.729 CSPF: Reroute due to re-optimization
4 Oct 13 15:15:14.984 Record Route: 192.168.13.3 192.168.37.7
3 Oct 13 15:15:14.984 Up
2 Oct 13 15:15:14.830 Originate Call
1 Oct 13 15:15:14.830 CSPF: computation result accepted 192.168.13.3
192.168.37.7
Created: Thu Oct 13 15:13:46 2011
Total 1 displayed, Up 1, Down 0
Meaning
Related
Documentation
Check the standby secondary path. The effective link cost for P2>PE2 is 11 (with the added
srlg-cost of 10). CSPF computes the secondary path as PE1>P3>P4>P5>PE2 with a CSPF
link metric of 4.
•
SRLG Overview on page 36
•
Example: Excluding SRLG Links Completely for the Secondary LSP on page 80
•
srlg on page 321
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•
srlg-cost on page 322
•
srlg-value on page 322
Example: Excluding SRLG Links Completely for the Secondary LSP
This example shows how to configure the exclude-srlg option to exclude Shared Risk
Link Group (SRLG) links for the secondary label-switched path (LSP).
•
Requirements on page 80
•
Overview on page 80
•
Configuration on page 81
•
Verification on page 84
Requirements
This example uses the following hardware and software components:
•
M Series, MX Series, or T Series devices
•
Junos OS Release 11.4 or later running on all the devices
Overview
For critical links where it is imperative to keep the secondary and primary paths completely
disjoint from any common SRLG, you can optionally configure the exclude-srlg statement
at the [edit protocols mpls] or [edit protocols mpls label-switched-path path-name]
hierarchy levels. For logical systems, you configure the exclude-srlg statement at the edit
logical-systems protocols mpls[edit logical-systems logical-system-name protocols mpls
label-switched-path path-name] hierarchy level.
If exclude-srlg is configured, the Constrained Shortest Path First (CSPF) algorithm
excludes any link belonging to the set of SRLGs in the primary path. If exclude-srlg is not
configured, and if a link belongs to the set of SRLGs in the primary path, CSPF adds the
SRLG cost to the metric, but still accepts the link for computing the path.
In this example, PE1 is the ingress router and PE2 is the egress router. P1, P2, and P3, P4,
and P5 are transit routers. OSPF is configured on all the routers as the interior gateway
protocol (IGP). SRLG is configured on all seven routers. The primary path includes SRLG
srlg-a. For the standby secondary path, the link P2>PE2 belongs to SRLG srlg-a. Because
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Chapter 4: MPLS Router Configuration Guidelines
exclude-srlg is configured, CSPF rejects link P2>PE2 as the link belongs to the SRLG srlg-a.
Therefore, the computed standby secondary path is PE1>P3>P4>P5>PE2.
Configuration
CLI Quick
Configuration
Router PE1
To quickly configure this section of the example, copy the following commands, paste
them into a text file, remove any line breaks, change any details necessary to match your
network configuration, and then copy and paste the commands into the CLI at the [edit]
hierarchy level.
set interfaces ge-0/0/1 unit 0 family inet address 192.168.12.1/24
set interfaces ge-0/0/1 unit 0 family mpls
set interfaces ge-0/0/2 unit 0 family inet address 192.168.13.1/24
set interfaces ge-0/0/2 unit 0 family mpls
set interfaces ge-0/0/3 unit 0 family inet address 192.168.14.1/24
set interfaces ge-0/0/3 unit 0 family mpls
set interfaces lo0 unit 0 family inet address 10.255.0.1/32
set routing-options srlg srlg-a srlg-value 101
set protocols rsvp interface ge-0/0/1.0
set protocols rsvp interface ge-0/0/2.0
set protocols rsvp interface ge-0/0/3.0
set protocols mpls optimize-timer 120
set protocols mpls exclude-srlg
set protocols mpls label-switched-path pe1-pe2 to 10.255.0.7
set protocols mpls label-switched-path pe1-pe2 primary via-p1
set protocols mpls label-switched-path pe1-pe2 secondary path2 standby
set protocols mpls path via-p1 10.255.0.2 strict
set protocols mpls path path2
set protocols mpls interface ge-0/0/1.0
set protocols mpls interface ge-0/0/2.0
set protocols mpls interface ge-0/0/3.0
set protocols ospf traffic-engineering
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set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
set protocols ospf area 0.0.0.0 interface ge-0/0/2.0
set protocols ospf area 0.0.0.0 interface ge-0/0/3.0
set protocols ospf area 0.0.0.0 interface lo0.0
Step-by-Step
Procedure
The following example requires you to navigate various levels in the configuration
hierarchy. For information about navigating the CLI, see the Junos OS CLI User Guide.
1.
Configure the device interfaces.
[edit interfaces]
user@PE1# set ge-0/0/1 unit 0 family inet address 192.168.12.1/24
user@PE1# set ge-0/0/1 unit 0 family mpls
user@PE1# set ge-0/0/2 unit 0 family inet address 192.168.13.1/24
user@PE1# set ge-0/0/2 unit 0 family mpls
user@PE1# set ge-0/0/3 unit 0 family inet address 192.168.14.1/24
user@PE1# set ge-0/0/3 unit 0 family mpls
user@PE1# set lo0 unit 0 family inet address 10.255.0.1/32
2.
Configure OSPF on the interfaces.
[edit protocols ospf]
user@PE1# set traffic-engineering
user@PE1# set area 0.0.0.0 interface ge-0/0/1.0
user@PE1# set area 0.0.0.0 interface ge-0/0/2.0
user@PE1# set area 0.0.0.0 interface ge-0/0/3.0
user@PE1# set area 0.0.0.0 interface lo0.0
3.
Configure the SRLG definitions.
[edit routing-options]
user@PE1# set routing-options srlg srlg-a srlg-value 101
4.
Configure MPLS and the LSPs.
[edit protocols mpls]
user@PE1# set interface ge-0/0/1.0
user@PE1# set interface ge-0/0/2.0
user@PE1# set interface ge-0/0/3.0
user@PE1# set optimize-timer 120
user@PE1# set exclude-srlg
user@PE1# set label-switched-path pe1-pe2 to 10.255.0.7
user@PE1# set label-switched-path pe1-pe2 primary via-p1
user@PE1# set label-switched-path pe1-pe2 secondary path2 standby
user@PE1# set path via-p1 10.255.0.2 strict
user@PE1# set path path2
5.
Configure the exclude-srlg statement to forcibly keep the links for the secondary
path completely disjoint from the primary LSP path.
user@PE1 set protocols mpls exclude-srlg
6.
Enable RSVP on the interfaces.
[edit protocols rsvp]
user@PE1# set interface ge-0/0/1.0
user@PE1# set interface ge-0/0/2.0
user@PE1# set interface ge-0/0/3.0
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Results
From configuration mode, confirm your configuration by entering the show interfaces,
show protocols ospf, show routing-options, show protocols mpls, and show protocols rsvp
commands. If the output does not display the intended configuration, repeat the
instructions in this example to correct the configuration.
user@PE1# show interfaces
interfaces {
ge-0/0/1 {
unit 0 {
family inet {
address 192.168.12.1/24;
}
family mpls;
}
}
ge-0/0/2 {
unit 0 {
family inet {
address 192.168.13.1/24;
}
family mpls;
}
}
ge-0/0/3 {
unit 0 {
family inet {
address 192.168.14.1/24;
}
family mpls;
}
}
lo0 {
unit 0 {
family inet {
address 10.255.0.1/32;
}
}
}
}
user@PE1# show protocols ospf
traffic-engineering;
area 0.0.0.0 {
interface ge-0/0/1.0;;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
interface lo0.0;
}
user@PE1# show protocols mpls
optimize-timer 120;
label-switched-path pe1-pe2 {
to 10.255.0.7;
primary via-p1;
secondary path2 {
standby;
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}
}
path via-p1 {
10.255.0.2 strict;
}
path path2;
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
user@PE1# show protocols rsvp
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
user@PE1# show routing-options
routing-options {
srlg {
srlg-a srlg-value 101;
}
}
If you are done configuring the device, enter commit from configuration mode.
NOTE: Repeat this procedure for every Juniper Networks router in the IGP
domain, after modifying the appropriate interface names, addresses, and
any other parameters for each router.
Verification
Confirm that the configuration is working properly.
Verifying the Secondary Path Link for the LSP
Purpose
Action
Verify that the link for the secondary path is completely disjoint from the primary path.
user@PE1> show mpls lsp show mpls lsp detail
Ingress LSP: 1 sessions
10.255.0.7
From: 10.255.0.1, State: Up, ActiveRoute: 0, LSPname: pe1-pe2
ActivePath: via-p1 (primary)
LSPtype: Static Configured
LoadBalance: Random
Encoding type: Packet, Switching type: Packet, GPID: IPv4
*Primary
via-p1
State: Up
Priorities: 7 0
OptimizeTimer: 120
SmartOptimizeTimer: 180
SRLG: srlg-a
Reoptimization in 77 second(s).
Computed ERO (S [L] denotes strict [loose] hops): (CSPF metric: 2)
192.168.12.2 S 192.168.27.7 S
Received RRO (ProtectionFlag 1=Available 2=InUse 4=B/W 8=Node 10=SoftPreempt
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20=Node-ID):
192.168.12.2 192.168.27.7
Standby
path2
State: Up
Priorities: 7 0
OptimizeTimer: 120
SmartOptimizeTimer: 180
Reoptimization in 106 second(s).
Computed ERO (S [L] denotes strict [loose] hops): (CSPF metric: 4)
192.168.14.4 S 192.168.45.5 S 192.168.56.6 S 192.168.67.7 S
Received RRO (ProtectionFlag 1=Available 2=InUse 4=B/W 8=Node 10=SoftPreempt
20=Node-ID):
192.168.14.4 192.168.45.5 192.168.56.6 192.168.67.7
Total 1 displayed, Up 1, Down 0
Link P1->PE2: SRLG srlg-a
Link P2->PE2: SRLG srlg-a
Primary path:
PE1-P1-PE2
(CSPF metric: 2)
Standby secondary: PE1-P3-P4-P5-PE2 (CSPF metric: 4)
Meaning
Related
Documentation
Primary path includes SRLG srlg-a. For the standby secondary path, the link P2>PE2
belongs to SRLG srlg-a. CSPF rejects link P2>PE2 because the link belongs to the SRLG
srlg-a.
•
SRLG Overview on page 36
•
Example: Configuring SRLG on page 71
•
exclude-srlg on page 265
Example: Configuring SRLG With Link Protection
This example shows how to configure SRLG with link protection without the exclude-srlg
option.
•
Requirements on page 85
•
Overview on page 85
•
Configuration on page 86
•
Verification on page 103
Requirements
This example uses the following hardware and software components:
•
M Series, MX Series, or T Series devices
•
Junos OS Release 11.4 or later running on all the devices
Overview
In this example, PE1 is the ingress router and PE2 is the egress router. P1, P2, and P3, P4,
and P5 are transit routers. OSPF is configured on all the routers as the interior gateway
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protocol (IGP). SRLG is configured on all seven routers. The link P1>PE2 (primary path)
and the link P2>PE2 belong to SRLG srlg-a.
You configure link protection for the interface P1>PE2 by including the link-protection
statement.
When SRLG srlg-a is configured on the link P1>PE2 and P2>PE2, the bypass takes the
longer path P1>P4>P5>PE2, not selecting the link P2>PE2 because of the added SRLG
cost for srlg-a.
Primary path
Secondary path
P2
srlg-a
PE1
PE2
P1
P3
P4
P5
g040926
srlg-a
Configuration
CLI Quick
Configuration
Router PE1
86
To quickly configure this section of the example, copy the following commands, paste
them into a text file, remove any line breaks, change any details necessary to match your
network configuration, and then copy and paste the commands into the CLI at the [edit]
hierarchy level.
set interfaces ge-0/0/1 unit 0 family inet address 192.168.12.1/24
set interfaces ge-0/0/1 unit 0 family mpls
set interfaces ge-0/0/2 unit 0 family inet address 192.168.13.1/24
set interfaces ge-0/0/2 unit 0 family mpls
set interfaces ge-0/0/3 unit 0 family inet address 192.168.14.1/24
set interfaces ge-0/0/3 unit 0 family mpls
set interfaces lo0 unit 0 family inet address 10.255.0.1/32
set routing-options srlg srlg-a srlg-value 101
set routing-options srlg srlg-a srlg-cost 10
set protocols rsvp interface ge-0/0/1.0
set protocols rsvp interface ge-0/0/2.0
set protocols rsvp interface ge-0/0/3.0
set protocols mpls optimize-timer 120
set protocols mpls label-switched-path pe1-pe2 to 10.255.0.7
set protocols mpls label-switched-path pe1-pe2 link-protection
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set protocols mpls label-switched-path pe1-pe2 primary via-p1
set protocols mpls label-switched-path pe1-pe2 secondary path2 standby
set protocols mpls path via-p1 10.255.0.2 strict
set protocols mpls path path2
set protocols mpls interface ge-0/0/1.0
set protocols mpls interface ge-0/0/2.0
set protocols mpls interface ge-0/0/3.0
set protocols ospf traffic-engineering
set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
set protocols ospf area 0.0.0.0 interface ge-0/0/2.0
set protocols ospf area 0.0.0.0 interface ge-0/0/3.0
set protocols ospf area 0.0.0.0 interface lo0.0
Router P1
set interfaces ge-0/0/1 unit 0 family inet address 192.168.12.2/24
set interfaces ge-0/0/1 unit 0 family mpls
set interfaces ge-0/0/2 unit 0 family inet address 192.168.27.2/24
set interfaces ge-0/0/2 unit 0 family mpls
set interfaces ge-0/0/3 unit 0 family inet address 192.168.23.2/24
set interfaces ge-0/0/3 unit 0 family mpls
set interfaces ge-0/0/4 unit 0 family inet address 192.168.25.2/24
set interfaces ge-0/0/4 unit 0 family mpls
set interfaces lo0 unit 0 family inet address 10.255.0.2/32
set routing-options srlg srlg-a srlg-value 101
set routing-options srlg srlg-a srlg-cost 10
set protocols rsvp interface ge-0/0/1.0
set protocols rsvp interface ge-0/0/2.0 link-protection
set protocols rsvp interface ge-0/0/3.0
set protocols rsvp interface ge-0/0/4.0
set protocols mpls interface ge-0/0/1.0
set protocols mpls interface ge-0/0/2.0 srlg srlg-a
set protocols mpls interface ge-0/0/3.0
set protocols mpls interface ge-0/0/4.0
set protocols ospf traffic-engineering
set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
set protocols ospf area 0.0.0.0 interface ge-0/0/2.0
set protocols ospf area 0.0.0.0 interface ge-0/0/3.0
set protocols ospf area 0.0.0.0 interface ge-0/0/4.0
set protocols ospf area 0.0.0.0 interface lo0.0
Router P2
set interfaces ge-0/0/1 unit 0 family inet address 192.168.13.3/24
set interfaces ge-0/0/1 unit 0 family mpls
set interfaces ge-0/0/2 unit 0 family inet address 192.168.37.3/24
set interfaces ge-0/0/2 unit 0 family mpls
set interfaces ge-0/0/3 unit 0 family inet address 192.168.23.3/24
set interfaces ge-0/0/3 unit 0 family mpls
set interfaces lo0 unit 0 family inet address 10.255.0.3/32
set routing-options srlg srlg-a srlg-value 101
set routing-options srlg srlg-a srlg-cost 10
set protocols rsvp interface ge-0/0/1.0
set protocols rsvp interface ge-0/0/2.0
set protocols rsvp interface ge-0/0/3.0
set protocols mpls interface ge-0/0/1.0
set protocols mpls interface ge-0/0/2.0 srlg srlg-a
set protocols mpls interface ge-0/0/3.0
set protocols ospf traffic-engineering
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set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
set protocols ospf area 0.0.0.0 interface ge-0/0/2.0
set protocols ospf area 0.0.0.0 interface ge-0/0/3.0
set protocols ospf area 0.0.0.0 interface lo0.0
88
Router P3
set interfaces ge-0/0/1 unit 0 family inet address 192.168.14.4/24
set interfaces ge-0/0/1 unit 0 family mpls
set interfaces ge-0/0/2 unit 0 family inet address 192.168.45.4/24
set interfaces ge-0/0/2 unit 0 family mpls
set interfaces lo0 unit 0 family inet address 10.255.0.4/32
set routing-options srlg srlg-a srlg-value 101
set routing-options srlg srlg-a srlg-cost 10
set protocols rsvp interface ge-0/0/1.0
set protocols rsvp interface ge-0/0/2.0
set protocols mpls interface ge-0/0/1.0
set protocols mpls interface ge-0/0/2.0
set protocols ospf traffic-engineering
set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
set protocols ospf area 0.0.0.0 interface ge-0/0/2.0
set protocols ospf area 0.0.0.0 interface lo0.0
Router P4
set interfaces ge-0/0/1 unit 0 family inet address 192.168.45.5/24
set interfaces ge-0/0/1 unit 0 family mpls
set interfaces ge-0/0/2 unit 0 family inet address 192.168.56.5/24
set interfaces ge-0/0/2 unit 0 family mpls
set interfaces ge-0/0/3 unit 0 family inet address 192.168.25.5/24
set interfaces ge-0/0/3 unit 0 family mpls
set interfaces lo0 unit 0 family inet address 10.255.0.5/32
set routing-options srlg srlg-a srlg-value 101
set routing-options srlg srlg-a srlg-cost 10
set protocols rsvp interface ge-0/0/1.0
set protocols rsvp interface ge-0/0/2.0
set protocols rsvp interface ge-0/0/3.0
set protocols mpls interface ge-0/0/1.0
set protocols mpls interface ge-0/0/2.0
set protocols mpls interface ge-0/0/3.0
set protocols ospf traffic-engineering
set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
set protocols ospf area 0.0.0.0 interface ge-0/0/2.0
set protocols ospf area 0.0.0.0 interface ge-0/0/3.0
set protocols ospf area 0.0.0.0 interface lo0.0
Router P5
set interfaces ge-0/0/1 unit 0 family inet address 192.168.56.6/24
set interfaces ge-0/0/1 unit 0 family mpls
set interfaces ge-0/0/2 unit 0 family inet address 192.168.67.6/24
set interfaces ge-0/0/2 unit 0 family mpls
set interfaces lo0 unit 0 family inet address 10.255.0.6/32
set routing-options srlg srlg-a srlg-value 101
set routing-options srlg srlg-a srlg-cost 10
set protocols rsvp interface ge-0/0/1.0
set protocols rsvp interface ge-0/0/2.0
set protocols mpls interface ge-0/0/1.0
set protocols mpls interface ge-0/0/2.0
set protocols ospf traffic-engineering
set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
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set protocols ospf area 0.0.0.0 interface ge-0/0/2.0
set protocols ospf area 0.0.0.0 interface lo0.0
Router PE2
set interfaces ge-0/0/1 unit 0 family inet address 192.168.27.7/24
set interfaces ge-0/0/1 unit 0 family mpls
set interfaces ge-0/0/2 unit 0 family inet address 192.168.37.7/24
set interfaces ge-0/0/2 unit 0 family mpls
set interfaces ge-0/0/3 unit 0 family inet address 192.168.67.7/24
set interfaces ge-0/0/3 unit 0 family mpls
set interfaces lo0 unit 0 family inet address 10.255.0.7/32
set routing-options srlg srlg-a srlg-value 101
set routing-options srlg srlg-a srlg-cost 10
set protocols rsvp interface ge-0/0/1.0
set protocols rsvp interface ge-0/0/2.0
set protocols rsvp interface ge-0/0/3.0
set protocols mpls interface ge-0/0/1.0
set protocols mpls interface ge-0/0/2.0
set protocols mpls interface ge-0/0/3.0
set protocols ospf traffic-engineering
set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
set protocols ospf area 0.0.0.0 interface ge-0/0/2.0
set protocols ospf area 0.0.0.0 interface ge-0/0/3.0
set protocols ospf area 0.0.0.0 interface lo0.0
Configuring Device PE1
Step-by-Step
Procedure
The following example requires you to navigate various levels in the configuration
hierarchy. For information about navigating the CLI, see the Junos OS CLI User Guide.
To configure the ingress router PE1:
1.
Configure the device interfaces.
[edit interfaces]
user@PE1# set ge-0/0/1 unit 0 family inet address 192.168.12.1/24
user@PE1# set ge-0/0/1 unit 0 family mpls
user@PE1# set ge-0/0/2 unit 0 family inet address 192.168.13.1/24
user@PE1# set ge-0/0/2 unit 0 family mpls
user@PE1# set ge-0/0/3 unit 0 family inet address 192.168.14.1/24
user@PE1# set ge-0/0/3 unit 0 family mpls
user@PE1# set lo0 unit 0 family inet address 10.255.0.1/32
2.
Configure OSPF on the interfaces.
[edit protocols ospf]
user@PE1# set traffic-engineering
user@PE1# set area 0.0.0.0 interface ge-0/0/1.0
user@PE1# set area 0.0.0.0 interface ge-0/0/2.0
user@PE1# set area 0.0.0.0 interface ge-0/0/3.0
user@PE1# set area 0.0.0.0 interface lo0.0
3.
Configure the SRLG definitions.
[edit routing-options]
user@PE1# set routing-options srlg srlg-a srlg-value 101
user@PE1# set routing-options srlg srlg-a srlg-cost 10
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4.
Configure MPLS and the LSPs and configure link protection for the pe1-pe2 LSP.
[edit protocols mpls]
user@PE1# set interface ge-0/0/1.0
user@PE1# set interface ge-0/0/2.0
user@PE1# set interface ge-0/0/3.0
user@PE1# set optimize-timer 120
user@PE1# set label-switched-path pe1-pe2 to 10.255.0.7
user@PE1# set protocols mpls label-switched-path pe1-pe2 link-protection
user@PE1# set label-switched-path pe1-pe2 primary via-p1
user@PE1# set label-switched-path pe1-pe2 secondary path2 standby
user@PE1# set path via-p1 10.255.0.2 strict
user@PE1# set path path2
5.
Enable RSVP on the interfaces.
[edit protocols rsvp]
user@PE1# set interface ge-0/0/1.0
user@PE1# set interface ge-0/0/2.0
user@PE1# set interface ge-0/0/3.0
Results
From configuration mode, confirm your configuration by entering the show interfaces,
show protocols ospf, show routing-options, show protocols mpls, and show protocols rsvp
commands. If the output does not display the intended configuration, repeat the
instructions in this example to correct the configuration.
user@PE1# show interfaces
ge-0/0/1 {
unit 0 {
family inet {
address 192.168.12.1/24;
}
family mpls;
}
}
ge-0/0/2 {
unit 0 {
family inet {
address 192.168.13.1/24;
}
family mpls;
}
}
ge-0/0/3 {
unit 0 {
family inet {
address 192.168.14.1/24;
}
family mpls;
}
}
lo0 {
unit 0 {
family inet {
address 10.255.0.1/32;
}
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}
}
}
user@PE1# show protocols ospf
traffic-engineering;
area 0.0.0.0 {
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
interface lo0.0;
}
user@PE1# show protocols mpls
optimize-timer 120;
label-switched-path pe1-pe2 {
to 10.255.0.7;
link-protection;
primary via-p1;
secondary path2 {
standby;
}
}
path via-p1 {
10.255.0.2 strict;
}
path path2;
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
user@PE1# show protocols rsvp
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
user@PE1# show routing-options
srlg {
srlg-a {
srlg-value 101;
srlg-cost 10;
}
}
If you are done configuring the device, enter commit from configuration mode.
Configuring Device P1
Step-by-Step
Procedure
The following example requires you to navigate various levels in the configuration
hierarchy. For information about navigating the CLI, see the Junos OS CLI User Guide.
To configure device P1:
1.
Configure the device interfaces.
[edit interfaces]
user@P1# set ge-0/0/1 unit 0 family inet address 192.168.12.2/24
user@P1# set ge-0/0/1 unit 0 family mpls
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user@P1# set ge-0/0/2 unit 0 family inet address 192.168.27.2/24
user@P1# set ge-0/0/2 unit 0 family mpls
user@P1# set ge-0/0/3 unit 0 family inet address 192.168.23.2/24
user@P1# set ge-0/0/3 unit 0 family mpls
user@P1# set ge-0/0/4 unit 0 family inet address 192.168.25.2/24
user@P1# set ge-0/0/4 unit 0 family mpls
user@P1# set lo0 unit 0 family inet address 10.255.0.2/32
2.
Configure OSPF on the interfaces.
[edit protocols ospf]
user@P1# set traffic-engineering
user@P1# set area 0.0.0.0 interface ge-0/0/1.0
user@P1# set area 0.0.0.0 interface ge-0/0/2.0
user@P1# set area 0.0.0.0 interface ge-0/0/3.0
user@P1# set area 0.0.0.0 interface ge-0/0/4.0
user@P1# set area 0.0.0.0 interface lo0.0
3.
Configure the SRLG definitions.
[edit routing-options]
user@P1# set routing-options srlg srlg-a srlg-value 101
user@P1# set routing-options srlg srlg-a srlg-cost 10
4.
Configure MPLS on the interfaces and associate the SRLG srlg-a with interface
ge-0/0/2.0 for the P1>PE2 link.
[edit protocols mpls]
user@P1# set interface ge-0/0/1.0
user@P1# set interface ge-0/0/2.0 srlg srlg-a
user@P1# set interface ge-0/0/3.0
user@P1# set interface ge-0/0/4.0
5.
Enable RSVP on the interfaces and configure link-protection for interface ge-0/0/2.0.
[edit protocols rsvp]
user@P1# set interface ge-0/0/1.0
user@P1# set interface ge-0/0/2.0 link-protection
user@P1# set interface ge-0/0/3.0
user@P1# set interface ge-0/0/4.0
Results
From configuration mode, confirm your configuration by entering the show interfaces,
show protocols ospf, show protocols mpls, show protocols rsvp, and show routing-options
commands. If the output does not display the intended configuration, repeat the
instructions in this example to correct the configuration.
user@P1# show interfaces
ge-0/0/1 {
unit 0 {
family inet {
address 192.168.12.2/24;
}
family mpls;
}
}
ge-0/0/2 {
unit 0 {
family inet {
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address 192.168.27.2/24;
}
family mpls;
}
}
ge-0/0/3 {
unit 0 {
family inet {
address 192.168.23.2/24;
}
family mpls;
}
}
ge-0/0/4 {
unit 0 {
family inet {
address 192.168.25.2/24;
}
family mpls;
}
}
lo0 {
unit 0 {
family inet {
address 10.255.0.2/32;
}
}
}
user@P1# show protocols ospf
traffic-engineering;
area 0.0.0.0 {
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
interface ge-0/0/4.0;
interface lo0.0;
}
user@P1# show protocols mpls
interface ge-0/0/1.0;
interface ge-0/0/2.0 {
srlg srlg-a;
}
interface ge-0/0/3.0;
interface ge-0/0/4.0;
user@P1# show protocols rsvp
interface ge-0/0/1.0;
interface ge-0/0/2.0 {
link-protection;
}
interface ge-0/0/3.0;
interface ge-0/0/4.0;
user@P1# show routing-options
srlg {
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srlg-a {
srlg-value 101;
srlg-cost 10;
}
}
If you are done configuring the device, enter commit from configuration mode.
Configuring Device P2
Step-by-Step
Procedure
The following example requires you to navigate various levels in the configuration
hierarchy. For information about navigating the CLI, see the Junos OS CLI User Guide.
To configure P2:
1.
Configure the device interfaces.
[edit interfaces]
user@P2# set ge-0/0/1 unit 0 family inet address 192.168.13.3/24
user@P2# set ge-0/0/1 unit 0 family mpls
user@P2# set ge-0/0/2 unit 0 family inet address 192.168.37.3/24
user@P2# set ge-0/0/2 unit 0 family mpls
user@P2# set ge-0/0/3 unit 0 family inet address 192.168.23.3/24
user@P2# set ge-0/0/3 unit 0 family mpls
user@P2# set lo0 unit 0 family inet address 10.255.0.3/32
2.
Configure OSPF on the interfaces.
[edit protocols ospf]
user@P2# set traffic-engineering
user@P2# set area 0.0.0.0 interface ge-0/0/1.0
user@P2# set area 0.0.0.0 interface ge-0/0/2.0
user@P2# set area 0.0.0.0 interface ge-0/0/3.0
user@P2# set area 0.0.0.0 interface lo0.0
3.
Configure the SRLG definitions.
[edit routing-options]
user@P2# set routing-options srlg srlg-a srlg-value 101
user@P2# set routing-options srlg srlg-a srlg-cost 10
4.
Configure MPLS on the interfaces and associate the SRLG srlg-a with interface
ge-0/0/2.0 for the P2>PE2 link.
[edit protocols mpls]
user@P2# set interface ge-0/0/1.0
user@P2# set interface ge-0/0/2.0 srlg srlg-a
user@P2# set interface ge-0/0/3.0
5.
Enable RSVP on the interfaces.
[edit protocols rsvp]
user@P2# set interface ge-0/0/1.0
user@P2# set interface ge-0/0/2.0
user@P2# set interface ge-0/0/3.0
Results
94
From configuration mode, confirm your configuration by entering the show interfaces,
show protocols ospf, show protocols mpls, show protocols rsvp, and show routing-options
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Chapter 4: MPLS Router Configuration Guidelines
commands. If the output does not display the intended configuration, repeat the
instructions in this example to correct the configuration.
user@P2# show interfaces
ge-0/0/1 {
unit 0 {
family inet {
address 192.168.13.3/24;
}
family mpls;
}
}
ge-0/0/2 {
unit 0 {
family inet {
address 192.168.37.3/24;
}
family mpls;
}
}
ge-0/0/3 {
unit 0 {
family inet {
address 192.168.23.3/24;
}
family mpls;
}
}
lo0 {
unit 0 {
family inet {
address 10.255.0.3/32;
}
}
}
}
user@P2# show protocols ospf
traffic-engineering;
area 0.0.0.0 {
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
interface lo0.0;
}
user@P2# show protocols mpls
interface ge-0/0/1.0;
interface ge-0/0/2.0 {
srlg srlg-a;
}
interface ge-0/0/3.0;
}
user@P2# show protocols rsvp
interface ge-0/0/1.0;
interface ge-0/0/2.0;
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interface ge-0/0/3.0;
user@P2# show routing-options
srlg {
srlg-a {
srlg-value 101;
srlg-cost 10;
}
}
If you are done configuring the device, enter commit from configuration mode.
Configuring Device P3
Step-by-Step
Procedure
The following example requires you to navigate various levels in the configuration
hierarchy. For information about navigating the CLI, see the Junos OS CLI User Guide.
To configure P3:
1.
Configure the device interfaces.
[edit interfaces]
user@P3# set ge-0/0/1 unit 0 family inet address 192.168.14.4/24
user@P3# set ge-0/0/1 unit 0 family mpls
user@P3# set ge-0/0/2 unit 0 family inet address 192.168.45.4/24
user@P3# set ge-0/0/2 unit 0 family mpls
user@P3# set lo0 unit 0 family inet address 10.255.0.4/32
2.
Configure OSPF on the interfaces.
[edit protocols ospf]
user@P3# set traffic-engineering
user@P3# set area 0.0.0.0 interface ge-0/0/1.0
user@P3# set area 0.0.0.0 interface ge-0/0/2.0
user@P3# set area 0.0.0.0 interface lo0.0
3.
Configure the SRLG definitions.
[edit routing-options]
user@P3# set routing-options srlg srlg-a srlg-value 101
user@P3# set routing-options srlg srlg-a srlg-cost 10
4.
Configure MPLS on the interfaces.
[edit protocols mpls]
user@P3# set interface ge-0/0/1.0
user@P3# set interface ge-0/0/2.0
5.
Enable RSVP on the interfaces.
[edit protocols rsvp]
user@P3# set interface ge-0/0/1.0
user@P3# set interface ge-0/0/2.0
Results
96
From configuration mode, confirm your configuration by entering the show interfaces,
show protocols ospf, show protocols mpls, show protocols rsvp, and show routing-options
commands. If the output does not display the intended configuration, repeat the
instructions in this example to correct the configuration.
Copyright © 2011, Juniper Networks, Inc.
Chapter 4: MPLS Router Configuration Guidelines
user@P3# show interfaces
interfaces {
ge-0/0/1 {
unit 0 {
family inet {
address 192.168.14.4/24;
}
family mpls;
}
}
ge-0/0/2 {
unit 0 {
family inet {
address 192.168.45.4/24;
}
family mpls;
}
}
lo0 {
unit 0 {
family inet {
address 10.255.0.4/32;
}
}
}
}
user@P3# show protocols ospf
traffic-engineering;
area 0.0.0.0 {
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface lo0.0;
}
user@P3# show protocols mpls
interface ge-0/0/1.0;
interface ge-0/0/2.0;
user@P3# show protocols rsvp
interface ge-0/0/1.0;
interface ge-0/0/2.0;
user@P3# show routing-options
srlg {
srlg-a {
srlg-value 101;
srlg-cost 10;
}
}
If you are done configuring the device, enter commit from configuration mode.
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Junos OS 11.4 MPLS Applications Configuration Guide
Configuring Device P4
Step-by-Step
Procedure
The following example requires you to navigate various levels in the configuration
hierarchy. For information about navigating the CLI, see the Junos OS CLI User Guide.
To configure P4:
1.
Configure the device interfaces.
[edit interfaces]
user@P4# set ge-0/0/1 unit 0 family inet address 192.168.45.5/24
user@P4# set ge-0/0/1 unit 0 family mpls
user@P4# set ge-0/0/2 unit 0 family inet address 192.168.56.5/24
user@P4# set ge-0/0/2 unit 0 family mpls
user@P4# set ge-0/0/3 unit 0 family inet address 192.168.25.5/24
user@P4# set ge-0/0/3 unit 0 family mpls
user@P4# set lo0 unit 0 family inet address 10.255.0.5/32
2.
Configure OSPF on the interfaces.
[edit protocols ospf]
user@P4# set traffic-engineering
user@P4# set area 0.0.0.0 interface ge-0/0/1.0
user@P4# set area 0.0.0.0 interface ge-0/0/2.0
user@P4# set area 0.0.0.0 interface ge-0/0/3.0
user@P4# set area 0.0.0.0 interface lo0.0
3.
Configure the SRLG definitions.
[edit routing-options]
user@P4# set routing-options srlg srlg-a srlg-value 101
user@P4# set routing-options srlg srlg-a srlg-cost 10
4.
Configure MPLS on the interfaces.
[edit protocols mpls]
user@P4# set interface ge-0/0/1.0
user@P4# set interface ge-0/0/2.0
user@P4# set interface ge-0/0/3.0
5.
Enable RSVP on the interfaces.
[edit protocols rsvp]
user@P4# set interface ge-0/0/1.0
user@P4# set interface ge-0/0/2.0
user@P4# set interface ge-0/0/3.0
Results
From configuration mode, confirm your configuration by entering the show interfaces,
show protocols ospf, show protocols mpls, show protocols rsvp, and show routing-options
commands. If the output does not display the intended configuration, repeat the
instructions in this example to correct the configuration.
user@P4# show interfaces
ge-0/0/1 {
unit 0 {
family inet {
address 192.168.45.5/24;
}
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Chapter 4: MPLS Router Configuration Guidelines
family mpls;
}
}
ge-0/0/2 {
unit 0 {
family inet {
address 192.168.56.5/24;
}
family mpls;
}
}
ge-0/0/3 {
unit 0 {
family inet {
address 192.168.25.5/24;
}
family mpls;
}
}
lo0 {
unit 0 {
family inet {
address 10.255.0.5/32;
}
}
}
user@P4# show protocols ospf
traffic-engineering;
area 0.0.0.0 {
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
interface lo0.0;
}
user@P4# show protocols mpls
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
user@P4# show protocols rsvp
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
user@P4# show routing-options
srlg {
srlg-a {
srlg-value 101;
srlg-cost 10;
}
}
If you are done configuring the device, enter commit from configuration mode.
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Junos OS 11.4 MPLS Applications Configuration Guide
Configuring Device P5
Step-by-Step
Procedure
The following example requires you to navigate various levels in the configuration
hierarchy. For information about navigating the CLI, see the Junos OS CLI User Guide.
To configure P5:
1.
Configure the device interfaces.
[edit interfaces]
user@P5# set ge-0/0/1 unit 0 family inet address 192.168.56.6/24
user@P5# set ge-0/0/1 unit 0 family mpls
user@P5# set ge-0/0/2 unit 0 family inet address 192.168.67.6/24
user@P5# set ge-0/0/2 unit 0 family mpls
user@P5# set lo0 unit 0 family inet address 10.255.0.6/32
2.
Configure OSPF on the interfaces.
[edit protocols ospf]
user@P5# set traffic-engineering
user@P5# set area 0.0.0.0 interface ge-0/0/1.0
user@P5# set area 0.0.0.0 interface ge-0/0/2.0
user@P5# set area 0.0.0.0 interface lo0.0
3.
Configure the SRLG definitions.
[edit routing-options]
user@P5# set routing-options srlg srlg-a srlg-value 101
user@P5# set routing-options srlg srlg-a srlg-cost 10
4.
Configure MPLS on the interfaces.
[edit protocols mpls]
user@P5# set interface ge-0/0/1.0
user@P5# set interface ge-0/0/2.0
5.
Enable RSVP on the interfaces.
[edit protocols rsvp]
user@P5# set interface ge-0/0/1.0
user@P5# set interface ge-0/0/2.0
Results
From configuration mode, confirm your configuration by entering the show interfaces,
show protocols ospf, show protocols mpls, show protocols rsvp, and show routing-options
commands. If the output does not display the intended configuration, repeat the
instructions in this example to correct the configuration.
user@P5# show interfaces
ge-0/0/1 {
unit 0 {
family inet {
address 192.168.56.6/24;
}
family mpls;
}
}
ge-0/0/2 {
unit 0 {
100
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Chapter 4: MPLS Router Configuration Guidelines
family inet {
address 192.168.67.6/24;
}
family mpls;
}
}
lo0 {
unit 0 {
family inet {
address 10.255.0.6/32;
}
}
}
user@P5# show protocols ospf
traffic-engineering;
area 0.0.0.0 {
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface lo0.0;
}
user@P5# show protocols mpls
interface ge-0/0/1.0;
interface ge-0/0/2.0;
user@P5# show protocols rsvp
interface ge-0/0/1.0;
interface ge-0/0/2.0;
user@P5# show routing-options
srlg {
srlg-a {
srlg-value 101;
srlg-cost 10;
}
}
If you are done configuring the device, enter commit from configuration mode.
Configuring Device PE2
Step-by-Step
Procedure
The following example requires you to navigate various levels in the configuration
hierarchy. For information about navigating the CLI, see the Junos OS CLI User Guide.
To configure PE2:
1.
Configure the device interfaces.
[edit interfaces]
user@PE2# set ge-0/0/1 unit 0 family inet address 192.168.27.7/24
user@PE2# set ge-0/0/1 unit 0 family mpls
user@PE2# set ge-0/0/2 unit 0 family inet address 192.168.37.7/24
user@PE2# set ge-0/0/2 unit 0 family mpls
user@PE2# set ge-0/0/3 unit 0 family inet address 192.168.67.7/24
user@PE2# set ge-0/0/3 unit 0 family mpls
user@PE2# set lo0 unit 0 family inet address 10.255.0.7/32
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2.
Configure OSPF on the interfaces.
[edit protocols ospf]
user@PE2# set traffic-engineering
user@PE2# set area 0.0.0.0 interface ge-0/0/1.0
user@PE2# set area 0.0.0.0 interface ge-0/0/2.0
user@PE2# set area 0.0.0.0 interface ge-0/0/3.0
user@PE2# set area 0.0.0.0 interface lo0.0
3.
Configure the SRLG definitions.
[edit routing-options]
user@PE2# set routing-options srlg srlg-a srlg-value 101
user@PE2# set routing-options srlg srlg-a srlg-cost 10
4.
Configure MPLS on the interfaces.
[edit protocols mpls]
user@PE2# set interface ge-0/0/1.0
user@PE2# set interface ge-0/0/2.0
user@PE2# set interface ge-0/0/3.0
5.
Enable RSVP on the interfaces.
[edit protocols rsvp]
user@PE2# set interface ge-0/0/1.0
user@PE2# set interface ge-0/0/2.0
user@PE2# set interface ge-0/0/3.0
Results
From configuration mode, confirm your configuration by entering the show interfaces,
show protocols ospf, show protocols mpls, show protocols rsvp, and show routing-options
commands. If the output does not display the intended configuration, repeat the
instructions in this example to correct the configuration.
user@PE2# show interfaces
interfaces {
ge-0/0/1 {
unit 0 {
family inet {
address 192.168.27.7/24;
}
family mpls;
}
}
ge-0/0/2 {
unit 0 {
family inet {
address 192.168.37.7/24;
}
family mpls;
}
}
ge-0/0/3 {
unit 0 {
family inet {
address 192.168.67.7/24;
}
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family mpls;
}
}
lo0 {
unit 0 {
family inet {
address 10.255.0.7/32;
}
}
}
}
user@PE2# show protocols ospf
traffic-engineering;
area 0.0.0.0 {
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
interface lo0.0;
}
user@PE2# show protocols mpls
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
user@PE2# show protocols rsvp
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
user@PE2# show routing-options
srlg {
srlg-a {
srlg-value 101;
srlg-cost 10;
}
}
If you are done configuring the device, enter commit from configuration mode.
Verification
Confirm that the configuration is working properly.
Verifying the SRLG Cost Is Added to the TE Link
Purpose
Action
Verify that the SRLG cost is added to the TE link if it belongs to the SRLG of the protected
link. Issue the show ted link detail and show rsvp session extensive bypass commands on
device P1.
user@P1> show ted link detail
...
10.255.0.2->192.168.27.7-1, Local: 192.168.27.2, Remote: 0.0.0.0
Local interface index: 0, Remote interface index: 0
LocalPath: 0, Metric: 1, StaticBW: 1000Mbps, AvailBW: 1000Mbps
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Color: 0 <none>
SRLGs: srlg-a
localBW [0] 0bps [1] 0bps [2] 0bps [3] 0bps
localBW [4] 0bps [5] 0bps [6] 0bps [7] 0bps
[...]
10.255.0.3->192.168.37.7-1, Local: 192.168.37.3, Remote: 0.0.0.0
Local interface index: 0, Remote interface index: 0
LocalPath: 0, Metric: 1, StaticBW: 1000Mbps, AvailBW: 1000Mbps
Color: 0 <none>
SRLGs: srlg-a
localBW [0] 0bps [1] 0bps [2] 0bps [3] 0bps
localBW [4] 0bps [5] 0bps [6] 0bps [7] 0bps
...
user@P1> show rsvp session extensive bypass
Ingress RSVP: 1 sessions
10.255.0.7
From: 10.255.0.2, LSPstate: Up, ActiveRoute: 0
LSPname: Bypass->192.168.27.7
LSPtype: Static Configured
Suggested label received: -, Suggested label sent: Recovery label received: -, Recovery label sent: 299776
Resv style: 1 SE, Label in: -, Label out: 299776
Time left:
-, Since: Fri Oct 21 13:19:21 2011
Tspec: rate 0bps size 0bps peak Infbps m 20 M 1500
Port number: sender 1 receiver 52081 protocol 0
Type: Bypass LSP
Number of data route tunnel through: 1
Number of RSVP session tunnel through: 0
PATH rcvfrom: localclient
Adspec: sent MTU 1500
Path MTU: received 1500
PATH sentto: 192.168.25.5 (ge-0/0/4.0) 26 pkts
RESV rcvfrom: 192.168.25.5 (ge-0/0/4.0) 26 pkts
Explct route: 192.168.25.5 192.168.56.6 192.168.67.7
Record route: <self> 192.168.25.5 192.168.56.6 192.168.67.7
Total 1 displayed, Up 1, Down 0
Meaning
Related
Documentation
104
The shortest path for the bypass protecting the link P1->PE2 would have been
P1->P2->PE2. Because the links P1>PE2 and P2>PE2 both belong to SRLG srlg-a, the
SRLG cost of 10 for srlg-a is added to the metric for the link P2>PE2. This makes the
metric for the link P2>PE2 too high to be selected for the shortest path. Therefore, the
CSPF result for the computed path for the bypass becomes P1>P4>P5>PE2.
•
SRLG Overview on page 36
•
Example: Configuring SRLG on page 71
•
Example: Configuring SRLG With Link Protection With the exclude-srlg Option on
page 105
Copyright © 2011, Juniper Networks, Inc.
Chapter 4: MPLS Router Configuration Guidelines
Example: Configuring SRLG With Link Protection With the exclude-srlg Option
This example shows how to configure SRLG with link protection with the exclude-srlg
option.
•
Requirements on page 105
•
Overview on page 105
•
Configuration on page 106
•
Verification on page 123
Requirements
This example uses the following hardware and software components:
•
M Series, MX Series, or T Series devices
•
Junos OS Release 11.4 or later running on all the devices
Overview
In this example, PE1 is the ingress router and PE2 is the egress router. P1, P2, and P3, P4,
and P5 are transit routers. OSPF is configured on all the routers as the interior gateway
protocol (IGP). SRLG is configured on all seven routers. The link P1>PE2 (primary path)
and the link P2>PE2 belong to SRLG srlg-a.
You configure link protection for the interface P1>PE2 by including the link-protection
statement along with the exclude-srlg option. This makes the bypass LSP and the
protected link completely disjoint in any SRLG.
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When SRLG srlg-a is configured on the link P1>PE2 and P2>PE2, the link P2>PE2 is
rejected for CSPF consideration due to the exclude-srlg configuration. Therefore, the
computed path for the bypass becomes P1>P4>P5>PE2.
Primary path
Secondary path
P2
srlg-a
PE1
PE2
P1
P3
P4
P5
g040926
srlg-a
Configuration
CLI Quick
Configuration
Router PE1
106
To quickly configure this section of the example, copy the following commands, paste
them into a text file, remove any line breaks, change any details necessary to match your
network configuration, and then copy and paste the commands into the CLI at the [edit]
hierarchy level.
set interfaces ge-0/0/1 unit 0 family inet address 192.168.12.1/24
set interfaces ge-0/0/1 unit 0 family mpls
set interfaces ge-0/0/2 unit 0 family inet address 192.168.13.1/24
set interfaces ge-0/0/2 unit 0 family mpls
set interfaces ge-0/0/3 unit 0 family inet address 192.168.14.1/24
set interfaces ge-0/0/3 unit 0 family mpls
set interfaces lo0 unit 0 family inet address 10.255.0.1/32
set routing-options srlg srlg-a srlg-value 101
set protocols rsvp interface ge-0/0/1.0
set protocols rsvp interface ge-0/0/2.0
set protocols rsvp interface ge-0/0/3.0
set protocols mpls optimize-timer 120
set protocols mpls label-switched-path pe1-pe2 to 10.255.0.7
set protocols mpls label-switched-path pe1-pe2 link-protection
set protocols mpls label-switched-path pe1-pe2 primary via-p1
set protocols mpls label-switched-path pe1-pe2 secondary path2 standby
set protocols mpls path via-p1 10.255.0.2 strict
set protocols mpls path path2
set protocols mpls interface ge-0/0/1.0
set protocols mpls interface ge-0/0/2.0
set protocols mpls interface ge-0/0/3.0
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Chapter 4: MPLS Router Configuration Guidelines
set protocols ospf traffic-engineering
set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
set protocols ospf area 0.0.0.0 interface ge-0/0/2.0
set protocols ospf area 0.0.0.0 interface ge-0/0/3.0
set protocols ospf area 0.0.0.0 interface lo0.0
Router P1
set interfaces ge-0/0/1 unit 0 family inet address 192.168.12.2/24
set interfaces ge-0/0/1 unit 0 family mpls
set interfaces ge-0/0/2 unit 0 family inet address 192.168.27.2/24
set interfaces ge-0/0/2 unit 0 family mpls
set interfaces ge-0/0/3 unit 0 family inet address 192.168.23.2/24
set interfaces ge-0/0/3 unit 0 family mpls
set interfaces ge-0/0/4 unit 0 family inet address 192.168.25.2/24
set interfaces ge-0/0/4 unit 0 family mpls
set interfaces lo0 unit 0 family inet address 10.255.0.2/32
set routing-options srlg srlg-a srlg-value 101
set routing-options srlg srlg-a srlg-cost 10
set protocols rsvp interface ge-0/0/1.0
set protocols rsvp interface ge-0/0/2.0 link-protection exclude-srlg
set protocols mpls interface ge-0/0/1.0
set protocols mpls interface ge-0/0/2.0 srlg srlg-a
set protocols mpls interface ge-0/0/3.0
set protocols mpls interface ge-0/0/4.0
set protocols ospf traffic-engineering
set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
set protocols ospf area 0.0.0.0 interface ge-0/0/2.0
set protocols ospf area 0.0.0.0 interface ge-0/0/3.0
set protocols ospf area 0.0.0.0 interface ge-0/0/4.0
set protocols ospf area 0.0.0.0 interface lo0.0
Router P2
set interfaces ge-0/0/1 unit 0 family inet address 192.168.13.3/24
set interfaces ge-0/0/1 unit 0 family mpls
set interfaces ge-0/0/2 unit 0 family inet address 192.168.37.3/24
set interfaces ge-0/0/2 unit 0 family mpls
set interfaces ge-0/0/3 unit 0 family inet address 192.168.23.3/24
set interfaces ge-0/0/3 unit 0 family mpls
set interfaces lo0 unit 0 family inet address 10.255.0.3/32
set routing-options srlg srlg-a srlg-value 101
set routing-options srlg srlg-a srlg-cost 10
set protocols rsvp interface ge-0/0/1.0
set protocols rsvp interface ge-0/0/2.0
set protocols rsvp interface ge-0/0/3.0
set protocols mpls interface ge-0/0/1.0
set protocols mpls interface ge-0/0/2.0 srlg srlg-a
set protocols mpls interface ge-0/0/3.0
set protocols ospf traffic-engineering
set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
set protocols ospf area 0.0.0.0 interface ge-0/0/2.0
set protocols ospf area 0.0.0.0 interface ge-0/0/3.0
set protocols ospf area 0.0.0.0 interface lo0.0
Router P3
set interfaces ge-0/0/1 unit 0 family inet address 192.168.14.4/24
set interfaces ge-0/0/1 unit 0 family mpls
set interfaces ge-0/0/2 unit 0 family inet address 192.168.45.4/24
set interfaces ge-0/0/2 unit 0 family mpls
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set interfaces lo0 unit 0 family inet address 10.255.0.4/32
set routing-options srlg srlg-a srlg-value 101
set routing-options srlg srlg-a srlg-cost 10
set protocols rsvp interface ge-0/0/1.0
set protocols rsvp interface ge-0/0/2.0
set protocols mpls interface ge-0/0/1.0
set protocols mpls interface ge-0/0/2.0
set protocols ospf traffic-engineering
set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
set protocols ospf area 0.0.0.0 interface ge-0/0/2.0
set protocols ospf area 0.0.0.0 interface lo0.0
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Router P4
set interfaces ge-0/0/1 unit 0 family inet address 192.168.45.5/24
set interfaces ge-0/0/1 unit 0 family mpls
set interfaces ge-0/0/2 unit 0 family inet address 192.168.56.5/24
set interfaces ge-0/0/2 unit 0 family mpls
set interfaces ge-0/0/3 unit 0 family inet address 192.168.25.5/24
set interfaces ge-0/0/3 unit 0 family mpls
set interfaces lo0 unit 0 family inet address 10.255.0.5/32
set routing-options srlg srlg-a srlg-value 101
set routing-options srlg srlg-a srlg-cost 10
set protocols rsvp interface ge-0/0/1.0
set protocols rsvp interface ge-0/0/2.0
set protocols rsvp interface ge-0/0/3.0
set protocols mpls interface ge-0/0/1.0
set protocols mpls interface ge-0/0/2.0
set protocols mpls interface ge-0/0/3.0
set protocols ospf traffic-engineering
set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
set protocols ospf area 0.0.0.0 interface ge-0/0/2.0
set protocols ospf area 0.0.0.0 interface ge-0/0/3.0
set protocols ospf area 0.0.0.0 interface lo0.0
Router P5
set interfaces ge-0/0/1 unit 0 family inet address 192.168.56.6/24
set interfaces ge-0/0/1 unit 0 family mpls
set interfaces ge-0/0/2 unit 0 family inet address 192.168.67.6/24
set interfaces ge-0/0/2 unit 0 family mpls
set interfaces lo0 unit 0 family inet address 10.255.0.6/32
set routing-options srlg srlg-a srlg-value 101
set routing-options srlg srlg-a srlg-cost 10
set protocols rsvp interface ge-0/0/1.0
set protocols rsvp interface ge-0/0/2.0
set protocols mpls interface ge-0/0/1.0
set protocols mpls interface ge-0/0/2.0
set protocols ospf traffic-engineering
set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
set protocols ospf area 0.0.0.0 interface ge-0/0/2.0
set protocols ospf area 0.0.0.0 interface lo0.0
Router PE2
set interfaces ge-0/0/1 unit 0 family inet address 192.168.27.7/24
set interfaces ge-0/0/1 unit 0 family mpls
set interfaces ge-0/0/2 unit 0 family inet address 192.168.37.7/24
set interfaces ge-0/0/2 unit 0 family mpls
set interfaces ge-0/0/3 unit 0 family inet address 192.168.67.7/24
set interfaces ge-0/0/3 unit 0 family mpls
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Chapter 4: MPLS Router Configuration Guidelines
set interfaces lo0 unit 0 family inet address 10.255.0.7/32
set routing-options srlg srlg-a srlg-value 101
set routing-options srlg srlg-a srlg-cost 10
set protocols rsvp interface ge-0/0/1.0
set protocols rsvp interface ge-0/0/2.0
set protocols rsvp interface ge-0/0/3.0
set protocols mpls interface ge-0/0/1.0
set protocols mpls interface ge-0/0/2.0
set protocols mpls interface ge-0/0/3.0
set protocols ospf traffic-engineering
set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
set protocols ospf area 0.0.0.0 interface ge-0/0/2.0
set protocols ospf area 0.0.0.0 interface ge-0/0/3.0
set protocols ospf area 0.0.0.0 interface lo0.0
Configuring Device PE1
Step-by-Step
Procedure
The following example requires you to navigate various levels in the configuration
hierarchy. For information about navigating the CLI, see the Junos OS CLI User Guide.
To configure the ingress router PE1:
1.
Configure the device interfaces.
[edit interfaces]
user@PE1# set ge-0/0/1 unit 0 family inet address 192.168.12.1/24
user@PE1# set ge-0/0/1 unit 0 family mpls
user@PE1# set ge-0/0/2 unit 0 family inet address 192.168.13.1/24
user@PE1# set ge-0/0/2 unit 0 family mpls
user@PE1# set ge-0/0/3 unit 0 family inet address 192.168.14.1/24
user@PE1# set ge-0/0/3 unit 0 family mpls
user@PE1# set lo0 unit 0 family inet address 10.255.0.1/32
2.
Configure OSPF on the interfaces.
[edit protocols ospf]
user@PE1# set traffic-engineering
user@PE1# set area 0.0.0.0 interface ge-0/0/1.0
user@PE1# set area 0.0.0.0 interface ge-0/0/2.0
user@PE1# set area 0.0.0.0 interface ge-0/0/3.0
user@PE1# set area 0.0.0.0 interface lo0.0
3.
Configure the SRLG definitions.
[edit routing-options]
user@PE1# set routing-options srlg srlg-a srlg-value 101
user@PE1# set routing-options srlg srlg-a srlg-cost 10
4.
Configure MPLS and the LSPs and configure link protection for the pe1-pe2 LSP.
[edit protocols mpls]
user@PE1# set interface ge-0/0/1.0
user@PE1# set interface ge-0/0/2.0
user@PE1# set interface ge-0/0/3.0
user@PE1# set optimize-timer 120
user@PE1# set label-switched-path pe1-pe2 to 10.255.0.7
user@PE1# set protocols mpls label-switched-path pe1-pe2 link-protection
user@PE1# set label-switched-path pe1-pe2 primary via-p1
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user@PE1# set label-switched-path pe1-pe2 secondary path2 standby
user@PE1# set path via-p1 10.255.0.2 strict
user@PE1# set path path2
5.
Enable RSVP on the interfaces.
[edit protocols rsvp]
user@PE1# set interface ge-0/0/1.0
user@PE1# set interface ge-0/0/2.0
user@PE1# set interface ge-0/0/3.0
Results
From configuration mode, confirm your configuration by entering the show interfaces,
show protocols ospf, show routing-options, show protocols mpls, and show protocols rsvp
commands. If the output does not display the intended configuration, repeat the
instructions in this example to correct the configuration.
user@PE1# show interfaces
ge-0/0/1 {
unit 0 {
family inet {
address 192.168.12.1/24;
}
family mpls;
}
}
ge-0/0/2 {
unit 0 {
family inet {
address 192.168.13.1/24;
}
family mpls;
}
}
ge-0/0/3 {
unit 0 {
family inet {
address 192.168.14.1/24;
}
family mpls;
}
}
lo0 {
unit 0 {
family inet {
address 10.255.0.1/32;
}
}
}
}
user@PE1# show protocols ospf
traffic-engineering;
area 0.0.0.0 {
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
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interface lo0.0;
}
user@PE1# show protocols mpls
optimize-timer 120;
label-switched-path pe1-pe2 {
to 10.255.0.7;
link-protection;
primary via-p1;
secondary path2 {
standby;
}
}
path via-p1 {
10.255.0.2 strict;
}
path path2;
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
user@PE1# show protocols rsvp
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
user@PE1# show routing-options
srlg {
srlg-a {
srlg-value 101;
srlg-cost 10;
}
}
If you are done configuring the device, enter commit from configuration mode.
Configuring Device P1
Step-by-Step
Procedure
The following example requires you to navigate various levels in the configuration
hierarchy. For information about navigating the CLI, see the Junos OS CLI User Guide.
To configure device P1:
1.
Configure the device interfaces.
[edit interfaces]
user@P1# set ge-0/0/1 unit 0 family inet address 192.168.12.2/24
user@P1# set ge-0/0/1 unit 0 family mpls
user@P1# set ge-0/0/2 unit 0 family inet address 192.168.27.2/24
user@P1# set ge-0/0/2 unit 0 family mpls
user@P1# set ge-0/0/3 unit 0 family inet address 192.168.23.2/24
user@P1# set ge-0/0/3 unit 0 family mpls
user@P1# set ge-0/0/4 unit 0 family inet address 192.168.25.2/24
user@P1# set ge-0/0/4 unit 0 family mpls
user@P1# set lo0 unit 0 family inet address 10.255.0.2/32
2.
Configure OSPF on the interfaces.
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[edit protocols ospf]
user@P1# set traffic-engineering
user@P1# set area 0.0.0.0 interface ge-0/0/1.0
user@P1# set area 0.0.0.0 interface ge-0/0/2.0
user@P1# set area 0.0.0.0 interface ge-0/0/3.0
user@P1# set area 0.0.0.0 interface ge-0/0/4.0
user@P1# set area 0.0.0.0 interface lo0.0
3.
Configure the SRLG definitions.
[edit routing-options]
user@P1# set routing-options srlg srlg-a srlg-value 101
user@P1# set routing-options srlg srlg-a srlg-cost 10
4.
Configure MPLS on the interfaces and associate the SRLG with interface ge-0/0/2.0
for the P1>PE2 link.
[edit protocols mpls]
user@P1# set interface ge-0/0/1.0
user@P1# set interface ge-0/0/2.0 srlg srlg-a
user@P1# set interface ge-0/0/3.0
user@P1# set interface ge-0/0/4.0
5.
Enable RSVP on the interfaces and include the link-protection statement with the
exclude-srlg option for interface ge-0/0/2.0.
[edit protocols rsvp]
user@P1# set interface ge-0/0/1.0
user@P1# set interface ge-0/0/2.0 link-protection exclude-srlg
user@P1# set interface ge-0/0/3.0
user@P1# set interface ge-0/0/4.0
Results
From configuration mode, confirm your configuration by entering the show interfaces,
show protocols ospf, show protocols mpls, show protocols rsvp, and show routing-options
commands. If the output does not display the intended configuration, repeat the
instructions in this example to correct the configuration.
user@P1# show interfaces
ge-0/0/1 {
unit 0 {
family inet {
address 192.168.12.2/24;
}
family mpls;
}
}
ge-0/0/2 {
unit 0 {
family inet {
address 192.168.27.2/24;
}
family mpls;
}
}
ge-0/0/3 {
unit 0 {
family inet {
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address 192.168.23.2/24;
}
family mpls;
}
}
ge-0/0/4 {
unit 0 {
family inet {
address 192.168.25.2/24;
}
family mpls;
}
}
lo0 {
unit 0 {
family inet {
address 10.255.0.2/32;
}
}
}
user@P1# show protocols ospf
traffic-engineering;
area 0.0.0.0 {
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
interface ge-0/0/4.0;
interface lo0.0;
}
user@P1# show protocols mpls
interface ge-0/0/1.0;
interface ge-0/0/2.0 {
srlg srlg-a;
}
interface ge-0/0/3.0;
interface ge-0/0/4.0;
user@P1# show protocols rsvp
interface ge-0/0/1.0;
interface ge-0/0/2.0 {
link-protection {
exclude-srlg;
}
interface ge-0/0/3.0;
interface ge-0/0/4.0;
}
user@P1# show routing-options
srlg {
srlg-a {
srlg-value 101;
srlg-cost 10;
}
}
If you are done configuring the device, enter commit from configuration mode.
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Configuring Device P2
Step-by-Step
Procedure
The following example requires you to navigate various levels in the configuration
hierarchy. For information about navigating the CLI, see the Junos OS CLI User Guide.
To configure P2:
1.
Configure the device interfaces.
[edit interfaces]
user@P2# set ge-0/0/1 unit 0 family inet address 192.168.13.3/24
user@P2# set ge-0/0/1 unit 0 family mpls
user@P2# set ge-0/0/2 unit 0 family inet address 192.168.37.3/24
user@P2# set ge-0/0/2 unit 0 family mpls
user@P2# set ge-0/0/3 unit 0 family inet address 192.168.23.3/24
user@P2# set ge-0/0/3 unit 0 family mpls
user@P2# set lo0 unit 0 family inet address 10.255.0.3/32
2.
Configure OSPF on the interfaces.
[edit protocols ospf]
user@P2# set traffic-engineering
user@P2# set area 0.0.0.0 interface ge-0/0/1.0
user@P2# set area 0.0.0.0 interface ge-0/0/2.0
user@P2# set area 0.0.0.0 interface ge-0/0/3.0
user@P2# set area 0.0.0.0 interface lo0.0
3.
Configure the SRLG definitions.
[edit routing-options]
user@P2# set routing-options srlg srlg-a srlg-value 101
user@P2# set routing-options srlg srlg-a srlg-cost 10
4.
Configure MPLS on the interfaces and associate the SRLG with interface ge-0/0/2.0
for the P2>PE2 link.
[edit protocols mpls]
user@P2# set interface ge-0/0/1.0
user@P2# set interface ge-0/0/2.0 srlg srlg-a
user@P2# set interface ge-0/0/3.0
5.
Enable RSVP on the interfaces.
[edit protocols rsvp]
user@P2# set interface ge-0/0/1.0
user@P2# set interface ge-0/0/2.0
user@P2# set interface ge-0/0/3.0
Results
From configuration mode, confirm your configuration by entering the show interfaces,
show protocols ospf, show protocols mpls, show protocols rsvp, and show routing-options
commands. If the output does not display the intended configuration, repeat the
instructions in this example to correct the configuration.
user@P2# show interfaces
ge-0/0/1 {
unit 0 {
family inet {
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address 192.168.13.3/24;
}
family mpls;
}
}
ge-0/0/2 {
unit 0 {
family inet {
address 192.168.37.3/24;
}
family mpls;
}
}
ge-0/0/3 {
unit 0 {
family inet {
address 192.168.23.3/24;
}
family mpls;
}
}
lo0 {
unit 0 {
family inet {
address 10.255.0.3/32;
}
}
}
}
user@P2# show protocols ospf
traffic-engineering;
area 0.0.0.0 {
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
interface lo0.0;
}
user@P2# show protocols mpls
interface ge-0/0/1.0;
interface ge-0/0/2.0 {
srlg srlg-a;
}
interface ge-0/0/3.0;
}
user@P2# show protocols rsvp
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
user@P2# show routing-options
srlg {
srlg-a {
srlg-value 101;
srlg-cost 10;
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}
}
If you are done configuring the device, enter commit from configuration mode.
Configuring Device P3
Step-by-Step
Procedure
The following example requires you to navigate various levels in the configuration
hierarchy. For information about navigating the CLI, see the Junos OS CLI User Guide.
To configure P3:
1.
Configure the device interfaces.
[edit interfaces]
user@P3# set ge-0/0/1 unit 0 family inet address 192.168.14.4/24
user@P3# set ge-0/0/1 unit 0 family mpls
user@P3# set ge-0/0/2 unit 0 family inet address 192.168.45.4/24
user@P3# set ge-0/0/2 unit 0 family mpls
user@P3# set lo0 unit 0 family inet address 10.255.0.4/32
2.
Configure OSPF on the interfaces.
[edit protocols ospf]
user@P3# set traffic-engineering
user@P3# set area 0.0.0.0 interface ge-0/0/1.0
user@P3# set area 0.0.0.0 interface ge-0/0/2.0
user@P3# set area 0.0.0.0 interface lo0.0
3.
Configure the SRLG definitions.
[edit routing-options]
user@P3# set routing-options srlg srlg-a srlg-value 101
user@P3# set routing-options srlg srlg-a srlg-cost 10
4.
Configure MPLS on the interfaces.
[edit protocols mpls]
user@P3# set interface ge-0/0/1.0
user@P3# set interface ge-0/0/2.0
5.
Enable RSVP on the interfaces.
[edit protocols rsvp]
user@P3# set interface ge-0/0/1.0
user@P3# set interface ge-0/0/2.0
Results
From configuration mode, confirm your configuration by entering the show interfaces,
show protocols ospf, show protocols mpls, show protocols rsvp, and show routing-options
commands. If the output does not display the intended configuration, repeat the
instructions in this example to correct the configuration.
user@P3# show interfaces
interfaces {
ge-0/0/1 {
unit 0 {
family inet {
address 192.168.14.4/24;
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}
family mpls;
}
}
ge-0/0/2 {
unit 0 {
family inet {
address 192.168.45.4/24;
}
family mpls;
}
}
lo0 {
unit 0 {
family inet {
address 10.255.0.4/32;
}
}
}
}
user@P3# show protocols ospf
traffic-engineering;
area 0.0.0.0 {
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface lo0.0;
}
user@P3# show protocols mpls
interface ge-0/0/1.0;
interface ge-0/0/2.0;
user@P3# show protocols rsvp
interface ge-0/0/1.0;
interface ge-0/0/2.0;
user@P3# show routing-options
srlg {
srlg-a {
srlg-value 101;
srlg-cost 10;
}
}
If you are done configuring the device, enter commit from configuration mode.
Configuring Device P4
Step-by-Step
Procedure
The following example requires you to navigate various levels in the configuration
hierarchy. For information about navigating the CLI, see the Junos OS CLI User Guide.
To configure P4:
1.
Configure the device interfaces.
[edit interfaces]
user@P4# set ge-0/0/1 unit 0 family inet address 192.168.45.5/24
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user@P4# set ge-0/0/1 unit 0 family mpls
user@P4# set ge-0/0/2 unit 0 family inet address 192.168.56.5/24
user@P4# set ge-0/0/2 unit 0 family mpls
user@P4# set ge-0/0/3 unit 0 family inet address 192.168.25.5/24
user@P4# set ge-0/0/3 unit 0 family mpls
user@P4# set lo0 unit 0 family inet address 10.255.0.5/32
2.
Configure OSPF on the interfaces.
[edit protocols ospf]
user@P4# set traffic-engineering
user@P4# set area 0.0.0.0 interface ge-0/0/1.0
user@P4# set area 0.0.0.0 interface ge-0/0/2.0
user@P4# set area 0.0.0.0 interface ge-0/0/3.0
user@P4# set area 0.0.0.0 interface lo0.0
3.
Configure the SRLG definitions.
[edit routing-options]
user@P4# set routing-options srlg srlg-a srlg-value 101
user@P4# set routing-options srlg srlg-a srlg-cost 10
4.
Configure MPLS on the interfaces.
[edit protocols mpls]
user@P4# set interface ge-0/0/1.0
user@P4# set interface ge-0/0/2.0
user@P4# set interface ge-0/0/3.0
5.
Enable RSVP on the interfaces.
[edit protocols rsvp]
user@P4# set interface ge-0/0/1.0
user@P4# set interface ge-0/0/2.0
user@P4# set interface ge-0/0/3.0
Results
From configuration mode, confirm your configuration by entering the show interfaces,
show protocols ospf, show protocols mpls, show protocols rsvp, and show routing-options
commands. If the output does not display the intended configuration, repeat the
instructions in this example to correct the configuration.
user@P4# show interfaces
ge-0/0/1 {
unit 0 {
family inet {
address 192.168.45.5/24;
}
family mpls;
}
}
ge-0/0/2 {
unit 0 {
family inet {
address 192.168.56.5/24;
}
family mpls;
}
}
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ge-0/0/3 {
unit 0 {
family inet {
address 192.168.25.5/24;
}
family mpls;
}
}
lo0 {
unit 0 {
family inet {
address 10.255.0.5/32;
}
}
}
user@P4# show protocols ospf
traffic-engineering;
area 0.0.0.0 {
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
interface lo0.0;
}
user@P4# show protocols mpls
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
user@P4# show protocols rsvp
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
user@P4# show routing-options
srlg {
srlg-a {
srlg-value 101;
srlg-cost 10;
}
}
If you are done configuring the device, enter commit from configuration mode.
Configuring Device P5
Step-by-Step
Procedure
The following example requires you to navigate various levels in the configuration
hierarchy. For information about navigating the CLI, see the Junos OS CLI User Guide.
To configure P5:
1.
Configure the device interfaces.
[edit interfaces]
user@P5# set ge-0/0/1 unit 0 family inet address 192.168.56.6/24
user@P5# set ge-0/0/1 unit 0 family mpls
user@P5# set ge-0/0/2 unit 0 family inet address 192.168.67.6/24
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user@P5# set ge-0/0/2 unit 0 family mpls
user@P5# set lo0 unit 0 family inet address 10.255.0.6/32
2.
Configure OSPF on the interfaces.
[edit protocols ospf]
user@P5# set traffic-engineering
user@P5# set area 0.0.0.0 interface ge-0/0/1.0
user@P5# set area 0.0.0.0 interface ge-0/0/2.0
user@P5# set area 0.0.0.0 interface lo0.0
3.
Configure the SRLG definitions.
[edit routing-options]
user@P5# set routing-options srlg srlg-a srlg-value 101
user@P5# set routing-options srlg srlg-a srlg-cost 10
4.
Configure MPLS on the interfaces.
[edit protocols mpls]
user@P5# set interface ge-0/0/1.0
user@P5# set interface ge-0/0/2.0
5.
Enable RSVP on the interfaces.
[edit protocols rsvp]
user@P5# set interface ge-0/0/1.0
user@P5# set interface ge-0/0/2.0
Results
From configuration mode, confirm your configuration by entering the show interfaces,
show protocols ospf, show protocols mpls, show protocols rsvp, and show routing-options
commands. If the output does not display the intended configuration, repeat the
instructions in this example to correct the configuration.
user@P5# show interfaces
ge-0/0/1 {
unit 0 {
family inet {
address 192.168.56.6/24;
}
family mpls;
}
}
ge-0/0/2 {
unit 0 {
family inet {
address 192.168.67.6/24;
}
family mpls;
}
}
lo0 {
unit 0 {
family inet {
address 10.255.0.6/32;
}
}
}
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user@P5# show protocols ospf
traffic-engineering;
area 0.0.0.0 {
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface lo0.0;
}
user@P5# show protocols mpls
interface ge-0/0/1.0;
interface ge-0/0/2.0;
user@P5# show protocols rsvp
interface ge-0/0/1.0;
interface ge-0/0/2.0;
user@P5# show routing-options
srlg {
srlg-a {
srlg-value 101;
srlg-cost 10;
}
}
If you are done configuring the device, enter commit from configuration mode.
Configuring Device PE2
Step-by-Step
Procedure
The following example requires you to navigate various levels in the configuration
hierarchy. For information about navigating the CLI, see the Junos OS CLI User Guide.
To configure PE2:
1.
Configure the device interfaces.
[edit interfaces]
user@PE2# set ge-0/0/1 unit 0 family inet address 192.168.27.7/24
user@PE2# set ge-0/0/1 unit 0 family mpls
user@PE2# set ge-0/0/2 unit 0 family inet address 192.168.37.7/24
user@PE2# set ge-0/0/2 unit 0 family mpls
user@PE2# set ge-0/0/3 unit 0 family inet address 192.168.67.7/24
user@PE2# set ge-0/0/3 unit 0 family mpls
user@PE2# set lo0 unit 0 family inet address 10.255.0.7/32
2.
Configure OSPF on the interfaces.
[edit protocols ospf]
user@PE2# set traffic-engineering
user@PE2# set area 0.0.0.0 interface ge-0/0/1.0
user@PE2# set area 0.0.0.0 interface ge-0/0/2.0
user@PE2# set area 0.0.0.0 interface ge-0/0/3.0
user@PE2# set area 0.0.0.0 interface lo0.0
3.
Configure the SRLG definitions.
[edit routing-options]
user@PE2# set routing-options srlg srlg-a srlg-value 101
user@PE2# set routing-options srlg srlg-a srlg-cost 10
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4.
Configure MPLS on the interfaces.
[edit protocols mpls]
user@PE2# set interface ge-0/0/1.0
user@PE2# set interface ge-0/0/2.0
user@PE2# set interface ge-0/0/3.0
5.
Enable RSVP on the interfaces.
[edit protocols rsvp]
user@PE2# set interface ge-0/0/1.0
user@PE2# set interface ge-0/0/2.0
user@PE2# set interface ge-0/0/3.0
Results
From configuration mode, confirm your configuration by entering the show interfaces,
show protocols ospf, show protocols mpls, show protocols rsvp, and show routing-options
commands. If the output does not display the intended configuration, repeat the
instructions in this example to correct the configuration.
user@PE2# show interfaces
interfaces {
ge-0/0/1 {
unit 0 {
family inet {
address 192.168.27.7/24;
}
family mpls;
}
}
ge-0/0/2 {
unit 0 {
family inet {
address 192.168.37.7/24;
}
family mpls;
}
}
ge-0/0/3 {
unit 0 {
family inet {
address 192.168.67.7/24;
}
family mpls;
}
}
lo0 {
unit 0 {
family inet {
address 10.255.0.7/32;
}
}
}
}
user@PE2# show protocols ospf
traffic-engineering;
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area 0.0.0.0 {
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
interface lo0.0;
}
user@PE2# show protocols mpls
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
user@PE2# show protocols rsvp
interface ge-0/0/1.0;
interface ge-0/0/2.0;
interface ge-0/0/3.0;
user@PE2# show routing-options
srlg {
srlg-a {
srlg-value 101;
srlg-cost 10;
}
}
If you are done configuring the device, enter commit from configuration mode.
Verification
Confirm that the configuration is working properly.
Verifying the SRLG Cost Is Added to the TE Link
Purpose
Action
Verify that the TE link is excluded if it belongs to the SRLG of the protected link when
link-protection is configured with exclude-srlg. Issue the show ted link detail and show
rsvp session extensive bypass commands on device P1.
user@P1> show ted link detail
...
10.255.0.2->192.168.27.7-1, Local: 192.168.27.2, Remote: 0.0.0.0
Local interface index: 0, Remote interface index: 0
LocalPath: 0, Metric: 1, StaticBW: 1000Mbps, AvailBW: 1000Mbps
Color: 0 <none>
SRLGs: srlg-a
localBW [0] 0bps [1] 0bps [2] 0bps [3] 0bps
localBW [4] 0bps [5] 0bps [6] 0bps [7] 0bps
[...]
10.255.0.3->192.168.37.7-1, Local: 192.168.37.3, Remote: 0.0.0.0
Local interface index: 0, Remote interface index: 0
LocalPath: 0, Metric: 1, StaticBW: 1000Mbps, AvailBW: 1000Mbps
Color: 0 <none>
SRLGs: srlg-a
localBW [0] 0bps [1] 0bps [2] 0bps [3] 0bps
localBW [4] 0bps [5] 0bps [6] 0bps [7] 0bps
...
user@P1> show rsvp session extensive bypass
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Ingress RSVP: 1 sessions
10.255.0.7
From: 10.255.0.2, LSPstate: Up, ActiveRoute: 0
LSPname: Bypass->192.168.27.7
LSPtype: Static Configured
Suggested label received: -, Suggested label sent: Recovery label received: -, Recovery label sent: 299776
Resv style: 1 SE, Label in: -, Label out: 299776
Time left:
-, Since: Fri Oct 21 13:19:21 2011
Tspec: rate 0bps size 0bps peak Infbps m 20 M 1500
Port number: sender 1 receiver 52081 protocol 0
Type: Bypass LSP
Number of data route tunnel through: 1
Number of RSVP session tunnel through: 0
PATH rcvfrom: localclient
Adspec: sent MTU 1500
Path MTU: received 1500
PATH sentto: 192.168.25.5 (ge-0/0/4.0) 63 pkts
RESV rcvfrom: 192.168.25.5 (ge-0/0/4.0) 63 pkts
Explct route: 192.168.25.5 192.168.56.6 192.168.67.7
Record route: <self> 192.168.25.5 192.168.56.6 192.168.67.7
Total 1 displayed, Up 1, Down 0
Meaning
Related
Documentation
124
The shortest path for the bypass protecting the link P1>PE2 would have been P1>P2>PE2.
Because the links P1>PE2 and P2>PE2 both belong to SRLG srlg-a, the link P2>PE2 is
rejected for CSPF consideration due to the exclude-srlg constraint. Therefore, the
computed path for the bypass becomes P1>P4>P5>PE2.
•
SRLG Overview on page 36
•
Example: Configuring SRLG on page 71
•
Example: Configuring SRLG With Link Protection on page 85
•
exclude-srlg on page 265
Copyright © 2011, Juniper Networks, Inc.
CHAPTER 5
MPLS-Signaled LSP Configuration
Guidelines
MPLS-signaled label-switched paths (LSPs) run from a specific ingress router to a specific
egress router. This chapter describes how to configure LSPs. You can configure an LSP
so that the Junos OS makes all forwarding decisions, or you can configure some or all
routers in the path.
•
LSP Configuration Overview on page 126
•
Configuring the Ingress and Egress Router Addresses for LSPs on page 129
•
Configuring Primary and Secondary LSPs on page 131
•
Configuring a Text Description for LSPs on page 134
•
Configuring Fast Reroute on page 134
•
Configuring the Optimization Interval for Fast Reroute Paths on page 136
•
Adding LSP-Related Routes to the inet.3 Routing Table on page 136
•
Configuring the Connection Between Ingress and Egress Routers on page 137
•
Configuring LSP Metrics on page 138
•
Configuring CSPF Tie Breaking on page 139
•
Configuring Load Balancing Based on MPLS Labels on page 140
•
Disabling Normal TTL Decrementing on page 143
•
Configuring MPLS Soft Preemption on page 144
•
Configuring Automatic Bandwidth Allocation for LSPs on page 145
•
Disabling Constrained-Path LSP Computation on page 152
•
Configuring Administrative Groups on page 153
•
Configuring Extended Administrative Groups on page 155
•
Configuring Preference Values for LSPs on page 157
•
Disabling Path Route Recording on page 157
•
Configuring Class of Service for MPLS LSPs on page 157
•
Configuring Adaptive LSPs on page 159
•
Configuring Priority and Preemption for LSPs on page 161
•
Optimizing Signaled LSPs on page 161
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•
Configuring the Smart Optimize Timer on page 165
•
Limiting the Number of Hops in LSPs on page 166
•
Configuring the Bandwidth Value for LSPs on page 166
•
Configuring Hot Standby of Secondary Paths on page 166
•
Damping Advertisement of LSP State Changes on page 167
LSP Configuration Overview
To configure an MPLS-signaled LSP, you define the properties associated with the LSP
on the ingress router. Include the label-switched-path statement:
label-switched-path lsp-name {
disable;
adaptive;
admin-down;
admin-group {
exclude [ group-names ];
include-all [ group-names ];
include-any [ group-names ];
}
auto-bandwidth {
adjust-interval seconds;
adjust-threshold percent;
adjust-threshold-overflow-limit number;
maximum-bandwidth bps;
minimum-bandwidth bps;
monitor-bandwidth;
}
bandwidth bps {
ct0 bps;
ct1 bps;
ct2 bps;
ct3 bps;
}
class-of-service cos-value;
description text;
fast-reroute {
(bandwidth bps | bandwidth-percent percentage);
(exclude [ group-names ] | no-exclude);
hop-limit number;
(include-all [ group-names ] | no-include-all);
(include-any [ group-names ] | noinclude-any);
}
from address;
hop-limit number;
install {
destination-prefix/prefix-length <active>;
}
ldp-tunneling;
link-protection;
lsp-attributes {
encoding-type (ethernet | packet | pdh | sonet-sdh);
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gpid (ethernet | hdlc | ipv4 | pos-scrambling-crc-16 | pos-no-scrambling-crc-16 |
pos-scrambling-crc-32 | pos-no-scrambling-crc-32 | ppp);
signal-bandwidth type;
switching-type (fiber | lambda | psc-1 | tdm);
}
metric number;
no-cspf;
no-decrement-ttl;
node-link-protection;
optimize-timer seconds;
p2mp lsp-name;
policing {
filter filter-name;
no-auto-policing;
}
preference preference;
primary path-name {
adaptive;
admin-group {
exclude [ group-names ];
include-all [ group-names ];
include-any [ group-names ];
}
bandwidth bps {
ct0 bps;
ct1 bps;
ct2 bps;
ct3 bps;
}
class-of-service cos-value;
hop-limit number;
no-cspf;
no-decrement-ttl;
optimize-timer seconds;
preference preference;
priority setup-priority reservation-priority;
(record | no-record);
select (manual | unconditional);
standby;
}
priority setup-priority reservation-priority;
(random | least-fill | most-fill);
(record | no-record);
retry-limit number;
retry-timer seconds;
revert-timer seconds;
secondary path-name {
adaptive;
admin-group {
exclude [ group-names ];
include-all [ group-names ];
include-any [ group-names ];
}
bandwidth bps {
ct0 bps;
ct1 bps;
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ct2 bps;
ct3 bps;
}
class-of-service cos-value;
hop-limit number;
no-cspf;
no-decrement-ttl;
optimize-timer seconds;
preference preference;
priority setup-priority reservation-priority;
(record | no-record);
select (manual | unconditional);
standby;
}
soft-preemption {
cleanup-timer seconds;
}
standby;
to address;
traceoptions {
file filename <files number> <size size> <world-readable | no-world-readable>;
flag flag <flag-modifier> <disable>;
}
}
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls]
Each LSP must have a name, lsp-name, which can be up to 64 characters long and can
contain letters, digits, periods (.), and hyphens (-). The name must be unique within the
ingress router. For ease of management and identification, configure unique names across
the entire domain.
When you configure LSPs, you can specify the following statements either for each LSP
or for each path. For statements that you configure on a per-LSP basis, the value applies
to all paths in the LSP. For statements that you configure on a per-path basis, the path
value overrides the per-LSP value.
128
•
adaptive
•
admin-group (for LSPs)
•
auto-bandwidth
•
bandwidth (Fast Reroute, Signaled, and Multiclass LSPs)
•
class-of-service
•
hop-limit
•
no-cspf
•
optimize-timer
•
preference
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Chapter 5: MPLS-Signaled LSP Configuration Guidelines
•
priority
•
record or no-record
•
standby
For maintenance purposes, you can also configure the following attributes across all
LSPs and any paths within those LSPs:
•
admin-group (for LSPs)
•
bandwidth (Fast Reroute, Signaled, and Multiclass LSPs)
•
class-of-service
•
no-decrement-ttl
•
no-record
•
optimize-timer
•
preference
•
priority
•
smart-optimize-timer
•
standby
Configuring the Ingress and Egress Router Addresses for LSPs
The following sections describe how to specify the addresses of an LSP’s ingress and
egress routers:
•
Configuring the Ingress Router Address for LSPs on page 129
•
Configuring the Egress Router Address for LSPs on page 130
•
Preventing the Addition of Egress Router Addresses to Routing Tables on page 130
Configuring the Ingress Router Address for LSPs
The local router always is considered to be the ingress router, which is the beginning of
the LSP. The software automatically determines the proper outgoing interface and IP
address to use to reach the next router in an LSP.
By default, the router ID is chosen as the address of the ingress router. To override the
automatic selection of the source address, specify a source address in the from statement:
from address;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name]
The outgoing interface used by the LSP is not affected by the source address that
you configure.
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Configuring the Egress Router Address for LSPs
When configuring an LSP, you must specify the address of the egress router by including
the to statement:
to address;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name]
•
[edit protocols mpls static-label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls static-label-switched-path
lsp-name]
When you are setting up a signaled LSP, the to statement is the only required statement.
All other statements are optional.
After the LSP is established, the address of the egress router is installed as a host route
in the routing table. This route can then be used by BGP to forward traffic.
To have the software send BGP traffic over an LSP, the address of the egress router is
the same as the address of the BGP next hop. You can specify the egress router’s address
as any one of the router’s interface addresses or as the BGP router ID. If you specify a
different address, even if the address is on the same router, BGP traffic is not sent over
the LSP.
To determine the address of the BGP next hop, use the show route detail command. To
determine the destination address of an LSP, use the show mpls lsp command. To
determine whether a route has gone through an LSP, use the show route or show route
forwarding-table command. In the output of these last two commands, the
label-switched-path or push keyword included with the route indicates it has passed
through an LSP. Also, use the traceroute command to trace the actual path to which the
route leads. This is another indication whether a route has passed through an LSP.
You also can manipulate the address of the BGP next hop by defining a BGP import policy
filter that sets the route’s next-hop address.
Preventing the Addition of Egress Router Addresses to Routing Tables
You must configure an address using the to statement for all LSPs. This address is always
installed as a /32 prefix in the inet.3 or inet.0 routing tables. You can prevent the egress
router address configured using the to statement from being added to the inet.3 and
inet.0 routing tables by including the no-install-to-address statement.
Some reasons not to install the to statement address in the inet.3 and inet.0 routing
tables include the following:
•
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intended for secondary loopback addresses. If you configure an RSVP tunnel, including
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Chapter 5: MPLS-Signaled LSP Configuration Guidelines
the no-install-to-address statement, and then configure an install pfx/ <active> policy
later, you can do the following:
•
•
Verify that the LSP was set up correctly without impacting traffic.
•
Map traffic to the LSP in incremental steps.
•
Map traffic to the destination loopback address (the BGP next hop) by removing
the no-install-to-address statement once troubleshooting is complete.
Prevent CCC connections from losing IP traffic. When an LSP determines that it does
not belong to a connection, it installs the address specified with the to statement in
the inet.3 routing table. IP traffic is then forwarded to the CCC remote endpoint, which
can cause some types of PICs to fail.
To prevent the egress router address configured using the to statement from being added
to the inet.3 and inet.0 routing tables, include the no-install-to-address statement:
no-install-to-address;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name]
•
[edit protocols mpls static-label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls static-label-switched-path
lsp-name]
Configuring Primary and Secondary LSPs
By default, an LSP routes itself hop-by-hop toward the egress router. The LSP tends to
follow the shortest path as dictated by the local routing table, usually taking the same
path as destination-based, best-effort traffic. These paths are “soft” in nature because
they automatically reroute themselves whenever a change occurs in a routing table or
in the status of a node or link.
To configure the path so that it follows a particular route, create a named path using the
path statement, as described in “Creating Named Paths” on page 56. Then apply the
named path by including the primary or secondary statement. A named path can be
referenced by any number of LSPs.
To configure primary and secondary paths for an LSP, complete the steps in the following
sections:
•
Configuring Primary and Secondary Paths for an LSP on page 132
•
Configuring the Revert Timer for LSPs on page 132
•
Specifying the Conditions for Path Selection on page 133
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Configuring Primary and Secondary Paths for an LSP
The primary statement creates the primary path, which is the LSP’s preferred path. The
secondary statement creates an alternative path. If the primary path can no longer reach
the egress router, the alternative path is used.
To configure primary and secondary paths, include the primary and secondary statements:
primary path-name {
...
}
secondary path-name {
...
}
You can include these statements at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name]
When the software switches from the primary to a secondary path, it continuously
attempts to revert to the primary path, switching back to it when it is again reachable,
but no sooner than the retry time specified in the retry-timer statement. (For more
information, see “Configuring the Connection Between Ingress and Egress Routers” on
page 137.)
You can configure zero or one primary path. If you do not configure a primary path, the
first secondary path that is established is selected as the path.
You can configure zero or more secondary paths. All secondary paths are equal, and the
software tries them in the order that they are listed in the configuration. The software
does not attempt to switch among secondary paths. If the current secondary path is not
available, the next one is tried. To create a set of equal paths, specify secondary paths
without specifying a primary path.
If you do not specify any named paths, or if the path that you specify is empty, the software
makes all routing decisions necessary to reach the egress router.
Configuring the Revert Timer for LSPs
For LSPs configured with both primary and secondary paths, it is possible to configure
the revert timer. If a primary path goes down and traffic is switched to the secondary
path, the revert timer specifies the amount of time (in seconds) that the LSP must wait
before it can revert traffic back to a primary path. If during this time, the primary path
experiences any connectivity problems or stability problems, the timer is restarted. You
can configure the revert timer for both static and dynamic LSPs.
The Junos OS also makes a determination as to which path is the preferred path. The
preferred path is the path which has not encountered any difficulty in the last revert timer
period. If both the primary and secondary paths have encountered difficulty, neither path
is considered preferred. However, if one of the paths is dynamic and the other static, the
dynamic path is selected as the preferred path.
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The range of values you can configure for the revert timer is 0 through 65,535 seconds.
The default value is 60 seconds.
If you configure a value of 0 seconds, the traffic on the LSP, once switched from the
primary path to the secondary path, remains on the secondary path permanently (until
the network operator intervenes or until the secondary path goes down).
You can configure the revert timer for all LSPs on the router at the [edit protocols mpls]
hierarchy level or for a specific LSP at the [edit protocols mpls label-switched-path
lsp-name] hierarchy level.
To configure the revert timer, include the revert-timer statement:
revert-timer seconds;
For a list of hierarchy levels at which you can include this statement, see the summary
section for this statement.
Specifying the Conditions for Path Selection
When you have configured both primary and secondary paths for an LSP, you may need
to ensure that only a specific path is used.
The select statement is optional. If you do not include it, MPLS uses an automatic path
selection algorithm.
The manual and unconditional options do the following:
•
manual—The path is immediately selected for carrying traffic as long as it is up and
stable. Traffic is sent to other working paths if the current path is down or degraded
(receiving errors). This parameter overrides all other path attributes except the select
unconditional statement.
•
unconditional—The path is selected for carrying traffic unconditionally, regardless of
whether the path is currently down or degraded (receiving errors). This parameter
overrides all other path attributes.
Because the unconditional option switches to a path without regard to its current status,
be aware of the following potential consequences of specifying it:
•
If a path is not currently up when you enable the unconditional option, traffic can be
disrupted. Ensure that the path is functional before specifying the unconditional
option.
•
Once a path is selected because it has the unconditional option enabled, all other
paths for the LSP are gradually cleared, including the primary and standby paths.
No path can act as a standby to an unconditional path, so signaling those paths
serves no purpose.
For a specific path, the manual and unconditional options are mutually exclusive. You
can include the select statement with the manual option in the configuration of only one
of an LSP’s paths, and the select statement with the unconditional option in the
configuration of only one other of its paths.
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Enabling or disabling the manual and unconditional options for the select statement while
LSPs and their paths are up does not disrupt traffic.
To specify that a path be selected for carrying traffic if it is up and stable for at least the
revert timer window, include the select statement with the manual option:
select manual;
To specify that a path should always be selected for carrying traffic, even if it is currently
down or degraded, include the select statement with the unconditional option:
select unconditional;
You can include the select statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name (primary | secondary) path-name]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
(primary | secondary) path-name]
Configuring a Text Description for LSPs
You can provide a textual description for the LSP. Enclose any descriptive text that
includes spaces in quotation marks (" "). Any descriptive text you include is displayed in
the output of the show mpls lsp detail command and has no effect on the operation of
the LSP.
To provide a textual description for the LSP, include the description statement:
description text;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name]
•
[edit protocols mpls static-label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls static-label-switched-path
lsp-name]
The description text can be no more than 80 characters in length.
Configuring Fast Reroute
Fast reroute provides a mechanism for automatically rerouting traffic on an LSP if a node
or link in an LSP fails, thus reducing the loss of packets traveling over the LSP.
To configure fast reroute on an LSP, include the fast-reroute statement on the ingress
router:
fast-reroute {
(bandwidth bps | bandwidth-percent percentage);
(exclude [ group-names ] | no-exclude );
hop-limit number;
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(include-all [ group-names ] | no-include-all);
(include-any [ group-names ] | no-include-any);
}
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name]
You do not need to configure fast reroute on the LSP’s transit and egress routers. Once
fast reroute is enabled, the ingress router signals all the downstream routers that fast
reroute is enabled on the LSP, and each downstream router does its best to set up detours
for the LSP. If a downstream router does not support fast reroute, it ignores the request
to set up detours and continues to support the LSP. A router that does not support fast
reroute will cause some of the detours to fail, but otherwise has no impact on the LSP.
NOTE: To enable PFE fast reroute, configure a routing policy statement with
the load-balance per-packet statement at the [edit policy-options
policy-statement policy-name then] hierarchy level on each of the routers
where traffic might be rerouted. See also “Configuring Load Balancing Across
RSVP LSPs” on page 376.
By default, no bandwidth is reserved for the rerouted path. To allocate bandwidth for
the rerouted path, include either the bandwidth statement or the bandwidth-percent
statement. You can only include one of these statements at a time. If you do not include
either the bandwidth statement or the bandwidth-percent statement, the default setting
is to not reserve bandwidth for the detour path.
When you include the bandwidth statement, you can specify the specific amount of
bandwidth (in bits per second [bps]) you want to reserve for the detour path. The
bandwidth does not need to be identical to that allocated for the LSP.
When you specify a bandwidth percent using the bandwidth-percent statement, the
detour path bandwidth is computed by multiplying the bandwidth percentage by the
bandwidth configured for the main traffic-engineered LSP. For information about how
to configure the bandwidth for a traffic-engineered LSP, see “Configuring
Traffic-Engineered LSPs” on page 186.
Hop-limit constraints define how many more routers a detour is allowed to traverse
compared with the LSP itself. By default, the hop limit is set to 6. For example, if an LSP
traverses 4 routers, any detour for the LSP can be up to 10 (that is, 4 + 6) router hops,
including the ingress and egress routers.
By default, a detour inherits the same administrative (coloring) group constraints as its
parent LSP when CSPF is determining the alternate path. Administrative groups, also
known as link coloring or resource class, are manually assigned attributes that describe
the “color” of links, such that links with the same color conceptually belong to the same
class. If you specify the include-any statement when configuring the parent LSP, all links
traversed by the alternate session must have at least one color found in the list of groups.
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If you specify the include-all statement when configuring the parent LSP, all links traversed
by the alternate session must have all of the colors found in the list of groups. If you
specify the exclude statement when configuring the parent LSP, none of the links must
have a color found in the list of groups. For more information about administrative group
constraints, see “Configuring Administrative Groups” on page 153.
Configuring the Optimization Interval for Fast Reroute Paths
You can enable path optimization for fast reroute by configuring the fast reroute optimize
timer. The optimize timer triggers a periodic optimization process that recomputes the
fast reroute detour LSPs to use network resources more efficiently.
To enable fast reroute path optimization, specify the number of seconds using the
optimize-timer option for the fast-reroute statement:
fast-reroute seconds;
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp]
•
[edit logical-systems logical-system-name protocols rsvp]
Adding LSP-Related Routes to the inet.3 Routing Table
By default, a host route toward the egress router is installed in the inet.3 routing table.
(The host route address is the one you configure in the to statement.) Installing the host
route allows BGP to perform next-hop resolution. It also prevents the host route from
interfering with prefixes learned from dynamic routing protocols and stored in the inet.0
routing table.
Unlike the routes in the inet.0 table, routes in the inet.3 table are not copied to the Packet
Forwarding Engine, and hence they cause no changes in the system forwarding table
directly. You cannot use the ping or traceroute command through these routes. The only
use for inet.3 is to permit BGP to perform next-hop resolution. To examine the inet.3
table, use the show route table inet.3 command.
To inject additional routes into the inet.3 routing table, include the install statement:
install {
destination-prefix <active>;
}
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name]
•
[edit protocols mpls static-label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls static-label-switched-path
lsp-name]
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The specified routes are installed as aliases into the routing table when the LSP is
established. Installing additional routes allows BGP to resolve next hops within the
specified prefix and to direct additional traffic for these next hops to a particular LSP.
Including the active option with the install statement installs the specified prefix into the
inet.0 routing table, which is the primary forwarding table. The result is a route that is
installed in the forwarding table any time the LSP is established, which means you can
ping or trace the route. Use this option with care, because this type of prefix is very similar
to a static route.
You use alias routes for routers that have multiple addresses being used as BGP next
hops, or for routers that are not MPLS capable. In either of these cases, the LSP can be
configured to another MPLS capable system within the local domain, which then acts
as a “border” router. The LSP then terminates on the border router and, from that router,
Layer 3 forwarding takes the packet to the true next-hop router.
In the case of an interconnect, the domain’s border router can act as the proxy router
and can advertise the prefix for the interconnect if the border router is not setting the
BGP next hop to itself.
In the case of a point of presence (POP) that has routers that do not support MPLS, one
router (for example, a core router) that supports MPLS can act as a proxy for the entire
POP and can inject a set of prefixes that cover the POP. Thus, all routers within the POP
can advertise themselves as interior BGP (IBGP) next hops, and traffic can follow the
LSP to reach the core router. This means that normal IGP routing would prevail within
the POP.
You cannot use the ping or traceroute commands on routes in the inet.3 routing table.
For BGP next-hop resolution, it makes no difference whether a route is in inet.0 or inet.3;
the route with the best match (longest mask) is chosen. Among multiple best-match
routes, the one with the highest preference value is chosen.
Configuring the Connection Between Ingress and Egress Routers
The ingress router might make many attempts to connect and reconnect to the egress
router using the primary path. You can control how often the ingress router tries to
establish a connection using the primary path and how long it waits between retry
attempts.
The retry timer configures how long the ingress router waits before trying to connect
again to the egress router using the primary path. The default retry time is 30 seconds.
The time can be from 1 through 600 seconds. To modify this value, include the retry-timer
statement:
retry-timer seconds;
You can configure this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name]
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By default, no limit is set to the number of times an ingress router attempts to establish
or reestablish a connection to the egress router using the primary path. To limit the number
of attempts, include the retry-limit statement:
retry-limit number;
You can configure this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name]
The limit can be a value up to 10,000. When the retry limit is exceeded, no more attempts
are made to establish a path connection. At this point, intervention is required to restart
the primary path.
If you set a retry limit, it is reset to 1 each time a successful primary path is created.
Configuring LSP Metrics
The LSP metric is used to indicate the ease or difficulty of sending traffic over a particular
LSP. Lower LSP metric values (lower cost) increase the likelihood of an LSP being used.
Conversely, high LSP metric values (higher cost) decrease the likelihood of an LSP being
used.
The LSP metric can be specified dynamically by the router or explicitly by the user as
described in the following sections:
•
Configuring Dynamic LSP Metrics on page 138
•
Configuring Static LSP Metrics on page 138
Configuring Dynamic LSP Metrics
If no specific metric is configured, an LSP attempts to track the IGP metric toward the
same destination (the to address of the LSP). IGP includes OSPF, IS-IS, Routing
Information Protocol (RIP), and static routes. BGP and other RSVP or LDP routes are
excluded.
For example, if the OSPF metric toward a router is 20, all LSPs toward that router
automatically inherit metric 20. If the OSPF toward a router later changes to a different
value, all LSP metrics change accordingly. If there are no IGP routes toward the router,
the LSP raises its metric to 65,535.
Note that in this case, the LSP metric is completely determined by IGP; it bears no
relationship to the actual path the LSP is currently traversing. If LSP reroutes (such as
through reoptimization), its metric does not change, and thus it remains transparent to
users. Dynamic metric is the default behavior; no configuration is required.
Configuring Static LSP Metrics
You can manually assign a fixed metric value to an LSP. Once configured with the metric
statement, the LSP metric is fixed and cannot change:
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metric number;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name]
•
[edit protocols mpls static-label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls static-label-switched-path
lsp-name]
The LSP metric has several uses:
•
When there are parallel LSPs with the same egress router, the metrics are compared
to determine which LSP has the lowest metric value (the lowest cost) and therefore
the preferred path to the destination. If the metrics are the same, the traffic is shared.
Adjusting the metric values can force traffic to prefer some LSPs over others, regardless
of the underlying IGP metric.
•
When an IGP shortcut is enabled (see “IGP Shortcuts” on page 37), an IGP route might
be installed in the routing table with an LSP as the next hop, if the LSP is on the shortest
path to the destination. In this case, the LSP metric is added to the other IGP metrics
to determine the total path metric. For example, if an LSP whose ingress router is X
and egress router is Y is on the shortest path to destination Z, the LSP metric is added
to the metric for the IGP route from Y to Z to determine the total cost of the path. If
several LSPs are potential next hops, the total metrics of the paths are compared to
determine which path is preferred (that is, has the lowest total metric). Or, IGP paths
and LSPs leading to the same destination could be compared by means of the metric
value to determine which path is preferred.
By adjusting the LSP metric, you can force traffic to prefer LSPs, prefer the IGP path,
or share the load among them.
•
If router X and Y are BGP peers and if there is an LSP between them, the LSP metric
represents the total cost to reach Y from X. If for any reason the LSP reroutes, the
underlying path cost might change significantly, but X’s cost to reach Y remains the
same (the LSP metric), which allows X to report through a BGP multiple exit
discriminator (MED) a stable metric to downstream neighbors. As long as Y remains
reachable through the LSP, no changes are visible to downstream BGP neighbors.
It is possible to configure IS-IS to ignore the configured LSP metric by including the
ignore-lsp-metrics statement at the [edit protocols isis traffic-engineering shortcuts]
hierarchy level. This statement removes the mutual dependency between IS-IS and
MPLS for path computation. For more information, see the Junos OS Routing Protocols
Configuration Guide.
Configuring CSPF Tie Breaking
When selecting a path for an LSP, CSPF uses a tie-breaking process if there are several
equal-cost paths. For information about how CSPF selects a path, see “How CSPF Selects
a Path” on page 33.
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You can configure one of the following statements (you can only configure one of these
statements at a time) to alter the behavior of CSPF tie-breaking:
•
To configure a random tie-breaking rule for CSPF to use to choose among equal-cost
paths, include the random statement:
random;
•
To prefer the path with the least-utilized links, include the least-fill statement:
least-fill;
•
To prefer the path with the most-utilized links, include the most-fill statement:
most-fill;
You can include each of these statements at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name]
Configuring Load Balancing Based on MPLS Labels
Juniper Networks routers can load-balance on a per-packet basis in MPLS. Load balancing
can be performed on information in both the IP header and on up to three MPLS labels,
providing a more uniform distribution of MPLS traffic to next hops. This feature is enabled
on supported platforms by default and requires no configuration.
Load balancing is used to evenly distribute traffic when the following conditions apply:
•
There are multiple equal-cost next hops over different interfaces to the same
destination.
•
There is a single next hop over an aggregated interface.
By default, when load balancing is used to help distribute traffic, Junos OS employs a
hash algorithm to select a next-hop address to install into the forwarding table. Whenever
the set of next hops for a destination changes in any way, the next-hop address is
reselected by means of the hash algorithm. You can configure how the hash algorithm
is used to load-balance traffic across a set of equal-cost label switched paths (LSPs).
An LSP tends to load-balance its placement by randomly selecting one of the equal-cost
next hops and using it exclusively. The random selection is made independently at each
transit router, which compares Interior Gateway Protocol (IGP) metrics alone. No
consideration is given to bandwidth or congestion levels.
To load-balance based on the MPLS label information, configure the family mpls
statement:
[edit forwarding-options hash-key]
family mpls {
label-1;
label-2;
label-3;
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no-labels;
no-label-1-exp;
payload {
ether-pseudowire;
ip {
layer-3-only;
port-data {
destination-lsb;
destination-msb;
source-lsb;
source-msb;
}
}
}
}
You can include this statement at the following hierarchy levels:
•
[edit logical-systems logical-system-name forwarding-options hash-key]
•
[edit forwarding-options hash-key]
This feature applies to aggregated Ethernet and aggregated SONET/SDH interfaces as
well as multiple equal-cost MPLS next hops. In addition, on the T Series, MX Series, M120,
and M320 routers only, you can configure load balancing for IPv4 traffic over Layer 2
Ethernet pseudowires. You can also configure load balancing for Ethernet pseudowires
based on IP information. The option to include IP information in the hash key provides
support for Ethernet circuit cross-connect (CCC) connections.
Table 3 on page 141 provides detailed information about all of the possible MPLS LSP
load-balancing options.
Table 3: MPLS LSP Load Balancing Options
Statement
MPLS LSP Load Balancing Options
label-l
Include the first label in the hash key. Use this option for single label packets.
label-2
Include the second label in the hash key. You must also configure the label-1 option. The entire first
label and the first 16 bits of the second label are used in the hash key.
label-3
Include the third label in the hash key. You must also configure the label-1 option and the label-2
option.
no-labels
Excludes MPLS labels from the hash key.
no-label-1-exp
Excludes the EXP bit of the top label from the hash key. You must also configure the label-l option.
For Layer 2 VPNs, the router could encounter a packet reordering problem. When a burst of traffic
pushes the customer traffic bandwidth to exceed its limits, the traffic might be affected in mid flow.
Packets might be reordered as a result. By excluding the EXP bit from the hash key, you can avoid this
reordering problem.
payload
Allows you to configure which parts of the IP packet payload to include in the hash key.
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Table 3: MPLS LSP Load Balancing Options (continued)
Statement
MPLS LSP Load Balancing Options
ether-pseudowire
(M120, M320, MX Series, and T Series routers only5)—Load-balance IPv4 traffic over Layer 2 Ethernet
pseudowires.
ip
Include the IPv4 or IPv6 address in the hash key. You must also configure either label-l or no-labels.
layer-3-only
Include only the Layer 3 IP information in the hash key. Excludes all of the port-data bytes from the
hash key.
port-data
Include the source and destination port field information. By default, the most significant byte and
least significant byte of the source and destination port fields are used in the hash key. To select
specific bytes to use in the hash key, include one or more of the source-msb, source-lsb, destination-msb,
and destination-lsb options at the [edit forwarding-options hash-key family mpls payload ip port-data]
hierarchy level. To prevent all four bytes from being hashed, include the layer-3-only statement at the
[edit forwarding-options hash-key family mpls payload ip] hierarchy level.
destination-lsb
Include the least significant byte of the destination port in the hash key. Can be combined with any
of the other port-data options.
destination-msb
Include the most significant byte of the destination port in the hash key. Can be combined with any
of the other port-data options.
source-lsb
Include the least significant byte of the source port in the hash key. Can be combined with any of the
other port-data options.
source-msb
Include the most significant byte of the source port in the hash key. Can be combined with any of the
other port-data options.
The following examples illustrate ways in which you can configure MPLS LSP load
balancing:
•
To include the IP address as well as the first label in the hash key, configure the label-1
statement and the ip option for the payload statement at the [edit forwarding-options
hash-key family mpls] hierarchy level:
[edit forwarding-options hash-key family mpls]
label-1;
payload {
ip;
}
•
To include the IP address as well as both the first and second labels in the hash key,
configure the label-1 and label-2 options and the ip option for the payload statement
at the [edit forwarding-options hash-key family mpls] hierarchy level:
[edit forwarding-options hash-key family mpls]
label-1;
label-2;
payload {
ip;
}
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NOTE: You can include this combination of statements on M320 and T
Series Core Routers only. If you include them on an M Series Multiservice
Edge Router, only the first MPLS label and the IP payload are used in the
hash key.
•
For Layer 2 VPNs, the router could encounter a packet reordering problem. When a
burst of traffic pushes the customer traffic bandwidth to exceed its limits, the traffic
might be affected in mid flow. Packets might be reordered as a result. By excluding
the EXP bit from the hash key, you can avoid this reordering problem. To exclude the
EXP bit of the first label from the hash calculations, include the no-label-1-exp statement
at the [edit forwarding-options hash-key family mpls] hierarchy level:
[edit forwarding-options hash-key family mpls]
label-1;
no-label-1-exp;
payload {
ip;
}
Related
Documentation
•
Configuring Load Balancing for Ethernet Pseudowires
Disabling Normal TTL Decrementing
By default, the time-to-live (TTL) field value in the packet header is decremented by 1
for every hop the packet traverses in the LSP, thereby preventing loops. If the TTL field
value reaches 0, packets are dropped, and an Internet Control Message Protocol (ICMP)
error packet is sent to the originating router.
If the normal TTL decrement is disabled, the TTL field of IP packets entering LSPs are
decremented by only 1 on transiting the LSP, making the LSP appear as a one-hop router
to diagnostic tools, such as traceroute. Decrementing the TTL field by 1 is done by the
ingress router, which pushes a label on IP packets with the TTL field in the label initialized
to 255. The label’s TTL field value is decremented by 1 for every hop the MPLS packet
traverses in the LSP. On the penultimate hop of the LSP, the router pops the label but
does not write the label’s TTL field value to the IP packet’s TTL field. Instead, when the
IP packet reaches the egress router, the IP packet’s TTL field value is decremented by 1.
When you use traceroute to diagnose problems with an LSP from outside that LSP,
traceroute sees the ingress router, even though the egress router performs the TTL
decrement. The behavior of traceroute is different if it is initiated from the ingress router
of the LSP. In this case, the egress router would be the first router to respond to traceroute.
You can disable normal TTL decrementing in an LSP so that the TTL field value does not
reach 0 before the packet reaches its destination, thus preventing the packet from being
dropped. You can also disable normal TTL decrementing to make the MPLS cloud appear
as a single hop, thereby hiding the network topology.
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There are two ways to disable TTL decrementing:
•
On the ingress of the LSP, if you include the no-decrement-ttl statement, the ingress
router negotiates with all downstream routers using a proprietary RSVP object, to
ensure all routers are in agreement. If negotiation succeeds, the whole LSP behaves
as one hop to transit IP traffic.
no-decrement-ttl;
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
NOTE: The RSVP object is proprietary to the Junos OS and might not work
with other software. This potential incompatibility applies only to
RSVP-signaled LSPs. When you include the no-decrement-ttl statement,
TTL hiding can be enforced on a per-LSP basis.
•
On the ingress router, you can include the no-propagate-ttl statement. The
no-propagate-ttl statement applies to all LSPs, regardless of whether they are
RSVP-signaled or LDP-signaled. Once set, all future LSPs traversing through this router
behave as a single hop to IP packets. LSPs established before you configure this
statement are not affected.
no-propagate-ttl;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls]
The operation of the no-propagate-ttl statement is interoperable with other vendors’
equipment. However, you must ensure that all routers are configured identically.
To configure the TTL behavior for a single VRF routing instance, include the
no-vrf-propagate-ttl or the vrf-propagate-ttl statement in the routing instance
configuration at the [edit routing-instances instance-name] hierarchy level. The
no-vrf-propagate-ttl or the vrf-propagate-ttl statement overrides the behavior configured
globally for the router. If the router is operating in default mode with normal TTL
decrementing, the no-vrf-propagate-ttl overrides the global behavior for the routing
instance on which the no-vrf-propagate-ttl statement is configured.
Related
Documentation
•
Example: Disabling Normal TTL Decrementing in a VRF Routing Instance (on Layer 3
VPNs in the Junos VPNs Configuration Guide
Configuring MPLS Soft Preemption
Soft preemption attempts to establish a new path for a preempted LSP before tearing
down the original LSP. The default behavior is to tear down a preempted LSP first, signal
a new path, and then reestablish the LSP over the new path. In the interval between
when the path is taken down and the new LSP is established, any traffic attempting to
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use the LSP is lost. Soft preemption prevents this type of traffic loss. The trade-off is
that during the time when an LSP is being soft preempted, two LSPs with their
corresponding bandwidth requirements are used until the original path is torn down.
MPLS soft preemption is useful for network maintenance. For example, you can move
all LSPs away from a particular interface, then take the interface down for maintenance
without interrupting traffic. MPLS soft preemption is described in detail in Internet draft
draft-ietf-mpls-soft-preemption-02.txt, MPLS Traffic Engineering Soft Preemption.
Soft preemption is a property of the LSP and is disabled by default. You configure it at
the ingress of an LSP by including the soft-preemption statement:
soft-preemption;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name]
You can also configure a timer for soft preemption. The timer designates the length of
time the router should wait before initiating a hard preemption of the LSP. At the end of
the time specified, the LSP is torn down and resignaled. The soft-preemption cleanup
timer has a default value of 30 seconds; the range of permissible values is 0 through
180 seconds. A value of 0 means that soft preemption is disabled. The soft-preemption
cleanup timer is global for all LSPs.
Configure the timer by including the cleanup-timer statement:
cleanup-timer seconds;
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp preemption soft-preemption]
•
[edit logical-systems logical-system-name protocols rsvp preemption soft-preemption]
NOTE: Soft preemption cannot be configured on LSPs for which secondary
paths or fast reroute has been configured. The configuration fails to commit.
However, you can enable soft preemption in conjunction with node and link
protection.
Configuring Automatic Bandwidth Allocation for LSPs
Automatic bandwidth allocation allows an MPLS tunnel to automatically adjust its
bandwidth allocation based on the volume of traffic flowing through the tunnel. You can
configure an LSP with minimal bandwidth, and this feature can dynamically adjust the
LSP’s bandwidth allocation based on current traffic patterns. The bandwidth adjustments
do not interrupt traffic flow through the tunnel.
At the end of the automatic bandwidth allocation time interval, the current maximum
average bandwidth usage is compared with the allocated bandwidth for the LSP. If the
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LSP needs more bandwidth, an attempt is made to set up a new path where bandwidth
is equal to the current maximum average usage. If the attempt is successful, the LSP’s
traffic is routed through the new path and the old path is removed. If the attempt fails,
the LSP continues to use its current path.
NOTE: You might not be able to use this feature to adjust the bandwidth of
fast-reroute LSPs. Because the LSPs use a fixed filter (FF) reservation style,
when a new path is signaled, the bandwidth might be double-counted.
Double-counting can prevent a fast-reroute LSP from ever adjusting its
bandwidth when automatic bandwidth allocation is enabled.
To configure automatic bandwidth allocation, complete the steps in the following
sections:
•
Configuring MPLS Statistics for Automatic Bandwidth Allocation on page 146
•
Configuring Automatic Bandwidth Allocation on LSPs on page 147
•
Requesting Automatic Bandwidth Allocation Adjustment on page 151
Configuring MPLS Statistics for Automatic Bandwidth Allocation
To enable automatic bandwidth allocation, you first need to configure MPLS statistics.
Include the auto-bandwidth option for the statistics statement. You can also use the
interval option to specify the interval for calculating the average bandwidth usage.
These settings apply to all LSPs configured on the router on which you have also
configured the auto-bandwidth statement at the [edit protocols mpls label-switched-path
label-switched-path-name] hierarchy level. You can also set the adjustment interval on
specific LSPs.
NOTE: To prevent unnecessary resignaling of LSPs, it is best to configure an
LSP adjustment interval that is at least three times longer than the MPLS
automatic bandwidth statistics interval. For example, if you configure a value
of 30 seconds for the MPLS automatic bandwidth statistics interval (interval
statement at the [edit protocols mpls statistics] hierarchy level), you should
configure a value of at least 90 seconds for the LSP adjustment interval
(adjust-interval statement at the [edit protocols mpls label-switched-path
label-switched-path-name auto-bandwidth] hierarchy level). See also
“Configuring the Automatic Bandwidth Allocation Interval” on page 147.
To configure the MPLS and automatic bandwidth allocation statistics, include the
statistics statement:
statistics {
auto-bandwidth;
file filename <files number> <size size> <world-readable | no-world-readable>;
interval seconds;
}
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You can include this statement at the following hierarchy levels:
•
[edit protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls]
Configuring Automatic Bandwidth Allocation on LSPs
To enable automatic bandwidth allocation on an LSP, include the auto-bandwidth
statement:
auto-bandwidth {
adjust-interval seconds;
adjust-threshold percent;
adjust-threshold-overflow-limit number;
minimum-bandwidth bps;
maximum-bandwidth bps;
monitor-bandwidth;
}
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name]
The statements configured at the [edit protocols mpls label-switched-path
label-switched-path-name auto-bandwidth] hierarchy level are optional and explained in
the following sections:
•
Configuring the Automatic Bandwidth Allocation Interval on page 147
•
Configuring the Maximum and Minimum Bounds of the LSP’s Bandwidth on page 148
•
Configuring the Automatic Bandwidth Adjustment Threshold on page 148
•
Configuring a Limit on Bandwidth Overflow Samples on page 149
•
Configuring Passive Bandwidth Utilization Monitoring on page 151
Configuring the Automatic Bandwidth Allocation Interval
At the end of the automatic bandwidth allocation interval, the automatic bandwidth
computation and new path setup process is triggered.
NOTE: To prevent unnecessary resignaling of LSPs, it is best to configure an
LSP adjustment interval that is at least three times longer than the MPLS
automatic bandwidth statistics interval. For example, if you configure a value
of 30 seconds for the MPLS automatic bandwidth statistics interval (interval
statement at the [edit protocols mpls statistics] hierarchy level), you should
configure a value of at least 90 seconds for the LSP adjustment interval
(adjust-interval statement at the [edit protocols mpls label-switched-path
label-switched-path-name auto-bandwidth] hierarchy level). See also
“Configuring MPLS Statistics for Automatic Bandwidth Allocation” on page 146.
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To specify the bandwidth reallocation interval in seconds for a specific LSP, include the
adjust-interval statement:
adjust-interval seconds;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name auto-bandwidth]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
auto-bandwidth]
Configuring the Maximum and Minimum Bounds of the LSP’s Bandwidth
You can maintain the LSP’s bandwidth between minimum and maximum bounds by
specifying values for the minimum-bandwidth and maximum-bandwidth statements.
To specify the minimum amount of bandwidth allocated for a specific LSP, include the
minimum-bandwidth statement:
minimum-bandwidth bps;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name auto-bandwidth]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
auto-bandwidth]
To specify the maximum amount of bandwidth allocated for a specific LSP, include the
maximum-bandwidth statement:
maximum-bandwidth bps;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name auto-bandwidth]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
auto-bandwidth]
Configuring the Automatic Bandwidth Adjustment Threshold
Use the adjust-threshold statement to specify the sensitivity of the automatic bandwidth
adjustment of an LSP to changes in bandwidth utilization. You can set the threshold for
when to trigger automatic bandwidth adjustments. When configured, bandwidth demand
for the current interval is determined and compared to the LSP’s current bandwidth
allocation. If the percentage difference in bandwidth is greater than or equal to the
specified adjust-threshold percentage, the LSP’s bandwidth is adjusted to the current
bandwidth demand.
For example, assume that the current bandwidth allocation is 100 megabits per second
(Mbps) and that the percentage configured for the adjust-threshold statement is 15
percent. If the bandwidth demand increases to 110 Mbps, the bandwidth allocation is not
adjusted. However, if the bandwidth demand increases to 120 Mbps (20 percent over
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the current allocation) or decreases to 80 Mbps (20 percent under the current allocation),
the bandwidth allocation is increased to 120 Mbps or decreased to 80 Mbps, respectively.
To configure the threshold for automatic bandwidth adjustment, include the
adjust-threshold statement:
adjust-threshold percent;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name auto-bandwidth]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
auto-bandwidth]
Configuring a Limit on Bandwidth Overflow Samples
The automatic bandwidth adjustment timer is a periodic timer which is triggered every
adjust interval to determine whether any bandwidth adjustments are required on the
LSP's active path. This interval is typically configured as a long period of time, usually
hours. If, at the end of adjust interval, the change in bandwidth is above a certain adjust
threshold, the LSP is resignaled with the new bandwidth.
During the automatic bandwidth adjustment interval, the router might receive a steady
increase in traffic (increasing bandwidth utilization) on an LSP, potentially causing
congestion or packet loss. To prevent this, you can define a second trigger to prematurely
expire the automatic bandwidth adjustment timer before the end of the current
adjustment interval.
Every statistics interval, the router samples the average bandwidth utilization of an LSP
and if this has exceeded the current maximum average bandwidth utilization, the
maximum average bandwidth utilization is updated.
During each sample period, the following conditions are also checked:
•
Is the current average bandwidth utilization above the active bandwidth of the path?
•
Has the difference between the average bandwidth utilization and the active bandwidth
exceeded the adjust threshold (bandwidth utilization has changed significantly)?
If these conditions are true, it is considered to be one bandwidth overflow sample. Using
the adjust-threshold-overflow-limit statement, you can define a limit on the number of
bandwidth overflow samples such that when the limit is reached, the current automatic
bandwidth adjustment timer is expired and a bandwidth adjustment is triggered. Once
this adjustment is complete, the normal automatic bandwidth adjustment timer is reset
to expire after the periodic adjustment interval.
To specify a limit on the number of bandwidth overflow samples before triggering an
automatic bandwidth allocation adjustment, configure the adjust-threshold-overflow-limit
statement:
adjust-threshold-overflow-limit number;
This statement can be configured at the following hierarchy levels:
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•
[edit protocols mpls label-switched-path lsp-name auto-bandwidth]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
auto-bandwidth]
You must also configure the adjust-threshold and maximum-bandwidth statements
whenever you configure the adjust-threshold-overflow-limit statement:
•
You must configure a nonzero value for the adjust-threshold statement if you configure
the adjust-threshold-overflow-limit statement. Any bandwidth increase below the
value configured for the adjust-threshold statement does not constitute an overflow
condition.
•
To prevent unlimited increases in LSP bandwidth (to limit overflow beyond a certain
bandwidth), you must also configure the maximum-bandwidth statement when you
configure the adjust-threshold-overflow-limit statement.
Failure to configure either of these statements when you configure the
adjust-threshold-overflow-limit statement results in a commit error.
The following describes the other aspects of the adjust-threshold-overflow-limit
statement:
•
It only applies to bandwidth overflows. If the bandwidth is decreasing, the normal
automatic bandwidth adjustment interval is used.
•
It does not affect manually triggered automatic bandwidth adjustment.
•
It applies to single-class DiffServ-TE LSPs.
•
Because the adjust-threshold-overflow-limit statement can trigger a bandwidth
adjustment, it cannot be enabled at the same time as the monitor-bandwidth statement
(for information about that statement, see “Configuring Passive Bandwidth Utilization
Monitoring” on page 151).
•
You cannot configure automatic bandwidth adjustments to occur more often than
every 300 seconds. The adjust-threshold-overflow-limit statement is subject to the
same minimum value with regard to the minimum frequency of adjustment allowed.
Overflow condition based adjustments can occur no sooner than 300 seconds from
the start of the overflow condition. Therefore it is required that:
sample interval x adjust-threshold-overflow-limit >= 300s
These values are checked during the commit operation. An error is returned if the value
is less than 300 seconds.
•
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If you change the value of the adjust-threshold-overflow-limit statement on a working
router, you can expect the following behavior:
•
If you increase the current value of the adjust-threshold-overflow-limit statement,
the old value is replaced with the new one.
•
If you decrease the current value of the adjust-threshold-overflow-limit statement
and the current bandwidth overflow count is less than the new value, the old value
is replaced with the new one.
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•
If you decrease the current value of the adjust-threshold-overflow-limit statement
and the current bandwidth overflow count is greater than the new value, the
adjustment timer is immediately expired and a bandwidth adjustment is initiated.
Configuring Passive Bandwidth Utilization Monitoring
Use the monitor-bandwidth statement to switch to a passive bandwidth utilization
monitoring mode. In this mode, no automatic bandwidth adjustments are made, but the
maximum average bandwidth utilization is continuously monitored and recorded.
To configure passive bandwidth utilization monitoring, include the monitor-bandwidth
statement:
monitor-bandwidth;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name auto-bandwidth]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
auto-bandwidth]
If you have configured an LSP with primary and secondary paths, the automatic bandwidth
allocation statistics are carried over to the secondary path if the primary path fails. For
example, consider a primary path whose adjustment interval is half complete and whose
maximum average bandwidth usage is currently calculated as 50 Mbps. If the primary
path suddenly fails, the time remaining for the next adjustment and the maximum average
bandwidth usage are carried over to the secondary path.
Requesting Automatic Bandwidth Allocation Adjustment
For MPLS LSP automatic bandwidth allocation adjustment, the minimum value for the
adjustment interval is 5 minutes (300 seconds). You might find it necessary to trigger a
bandwidth allocation adjustment manually, for example in the following circumstances:
•
When you are testing automatic bandwidth allocation in a network lab.
•
When the LSP is configured for automatic bandwidth allocation in monitor mode (the
monitor-bandwidth statement is included in the configuration as described in
“Configuring Passive Bandwidth Utilization Monitoring” on page 151), and want to initiate
an immediate bandwidth adjustment.
To use the request mpls lsp adjust-autobandwidth command, the following must be true:
•
Automatic bandwidth allocation must be enabled on the LSP.
•
The criteria required to trigger a bandwidth adjustment have been met (the difference
between the adjust bandwidth and the current LSP path bandwidth is greater than
the threshold limit).
A manually triggered bandwidth adjustment operates only on the active LSP path. Also,
if you have enabled periodic automatic bandwidth adjustment, the periodic automatic
bandwidth adjustment parameters (the adjustment interval and the maximum average
bandwidth) are not reset after a manual adjustment.
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For example, suppose the periodic adjust interval is 10 hours and there are currently
5 hours remaining before an automatic bandwidth adjustment is triggered. If you initiate
a manual adjustment with the request mpls lsp adjust-autobandwidth command, the
adjust timer is not reset and still has 5 hours remaining.
To manually trigger a bandwidth allocation adjustment, you need to use the request mpls
lsp adjust-autobandwidth command. You can trigger the command for all affected LSPs
on the router, or you can specify a particular LSP:
user@host> request mpls lsp adjust-autobandwidth
Once you execute this command, the automatic bandwidth adjustment validation process
is triggered. If all the criteria for adjustment are met, the LSP’s active path bandwidth is
adjusted to the adjusted bandwidth value determined during the validation process.
Disabling Constrained-Path LSP Computation
If the IGP is a link-state protocol (such as IS-IS or OSPF) and supports extensions that
allow the current bandwidth reservation on each router’s link to be reported,
constrained-path LSPs are computed by default.
The Junos implementations of IS-IS and OSPF include the extensions that support
constrained-path LSP computation.
•
IS-IS—These extensions are enabled by default. To disable this support, include the
disable statement at the [edit protocols isis traffic-engineering] hierarchy level, as
discussed in the Junos OS Routing Protocols Configuration Guide.
•
OSPF—These extensions are disabled by default. To enable this support, include the
traffic-engineering statement in the configurations of all routers running OSPF, as
described in the Junos OS Routing Protocols Configuration Guide.
If IS-IS is enabled on a router or you enable OSPF traffic engineering extensions, MPLS
performs the constrained-path LSP computation by default. For information about how
constrained-path LSP computation works, see “Constrained-Path LSP Computation”
on page 32.
Constrained-path LSPs have a greater chance of being established quickly and
successfully for the following reasons:
•
The LSP computation takes into account the current bandwidth reservation.
•
Constrained-path LSPs reroute themselves away from node failures and congestion.
When constrained-path LSP computation is enabled, you can configure the LSP so that
it is periodically reoptimized, as described in “Optimizing Signaled LSPs” on page 161.
When an LSP is being established or when an existing LSP fails, the constrained-path
LSP computation is repeated periodically at the interval specified by the retry timer until
the LSP is set up successfully. Once the LSP is set up, no recomputation is done. For more
information about the retry timer, see “Configuring the Connection Between Ingress and
Egress Routers” on page 137.
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By default, constrained-path LSP computation is enabled. You might want to disable
constrained-path LSP computation when all nodes do not support the necessary traffic
engineering extensions. To disable constrained-path LSP computation, include the
no-cspf statement:
no-cspf;
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
If you disable constrained-path LSP computation on LSPs by configuring the no-cspf
statement and then attempt to advertise other LSPs with lower metrics than the IGPs
from this router in either IS-IS or OSPF, new LSPs cannot be established.
Configuring Administrative Groups
Administrative groups, also known as link coloring or resource class, are manually assigned
attributes that describe the “color” of links, such that links with the same color
conceptually belong to the same class. You can use administrative groups to implement
a variety of policy-based LSP setups.
Administrative groups are meaningful only when constrained-path LSP computation is
enabled.
You can assign up to 32 names and values (in the range 0 through 31), which define a
series of names and their corresponding values. The administrative names and values
must be identical across all routers within a single domain.
NOTE: The administrative value is distinct from the priority. You configure
the priority for an LSP using the priority statement. See “Configuring Priority
and Preemption for LSPs” on page 161.
To configure administrative groups, follow these steps:
1.
Define multiple levels of service quality by including the admin-groups statement:
admin-groups {
group-name group-value;
}
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls]
The following configuration example illustrates how you might configure a set of
administrative names and values for a domain:
[edit protocols mpls]
admin-groups {
gold 1;
silver 2;
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copper 3;
best-effort 4;
}
2. Define the administrative groups to which an interface belongs. You can assign multiple
groups to an interface. Include the interface statement:
interface interface-name {
admin-group [ group-names ];
}
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls]
If you do not include the admin-group statement, an interface does not belong to any
group.
IGPs use the group information to build link-state packets, which are then flooded
throughout the network, providing information to all nodes in the network. At any
router, the IGP topology, as well as administrative groups of all the links, is available.
Changing the interface’s administrative group affects only new LSPs. Existing LSPs
on the interface are not preempted or recomputed to keep the network stable. If LSPs
need to be removed because of a group change, issue the clear rsvp session command.
3. Configure an administrative group constraint for each LSP or for each primary or
secondary LSP path. Include the label-switched-path statement:
label-switched-path lsp-name {
to address;
...
admin-group {
exclude [ group-names ];
include-all [ group-names ];
include-any [ group-names ];
}
primary path-name {
admin-group {
exclude [ group-names ];
include-all [ group-names ];
include-any [ group-names ];
}
}
secondary path-name {
admin-group {
exclude [ group-names ];
include-all [ group-names ];
include-any [ group-names ];
}
}
}
You can include the label-switched-path statement at the following hierarchy levels:
•
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•
[edit logical-systems logical-system-name protocols mpls]
If you omit the include-all, include-any, or exclude statements, the path computation
proceeds unchanged. The path computation is based on the constrained-path LSP
computation. For information about how the constrained-path LSP computation is
calculated, see “How CSPF Selects a Path” on page 33.
NOTE: Changing the LSP’s administrative group causes an immediate
recomputation of the route; therefore, the LSP might be rerouted.
Configuring Extended Administrative Groups
In MPLS traffic engineering, a link can be configured with a set of administrative groups
(also known as colors or resource classes). Administrative groups are carried in the interior
gateway protocol (IGP) (OSPFv2 and IS-IS) as a 32-bit value assigned to each link.
Juniper Networks routers normally interpret this 32-bit value as a bit mask with each bit
representing a group, limiting each network to a total of 32 distinct administrative groups
(value range 0 through 31).
You configure extended administrative groups, represented by a 32-bit value, expanding
the number of administrative groups supported in the network beyond just 32. The original
range of values available for administrative groups is still supported for backwards
compatibility.
The extended administrative groups configuration accepts a set of interfaces with a
corresponding set of extended administrative group names. It converts the names into
a set of 32-bit values and propagates this information into the IGP. The extended
administrative group values are global and must be identically configured on all the
supported routers participating in the network. The domain-wide extended administrative
groups database, learned from other routers through IGP flooding, is used by Constrained
Shortest Path First (CSPF) for path computation.
The following procedure describes how to configure extended administrative groups:
1.
Configure the admin-groups-extended-range statement:
admin-groups-extended-range {
maximum maximum-number;
mininum minimum-number;
}
You can include this statement at the following hierarchy levels:
•
[edit routing-options]
•
[edit logical-systems logical-system-name routing-options]
The admin-groups-extended-range statement includes the minimum and maximum
options. The range maximum must be greater than the range minimum.
2. Configure the admin-groups-extended statement:
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admin-groups-extended group-name {
group-value group-identifier;
}
You can include this statement at the following hierarchy levels:
•
[edit routing-options]
•
[edit logical-systems logical-system-name routing-options]
The admin-groups-extended statement enables you to configure a group name and
group value for the administrative group. The group value must be within the range
of values configured using the admin-groups-extended-range statement.
3. The extended administrative groups for an MPLS interface consist of the set of
extended administrative group names assigned for the interface. The interface
extended administrative group names must be configured for the global extended
administrative groups.
To configure an extended administrative group for an MPLS interface, specify the
administrative group name within the MPLS interface configuration using the
admin-groups-extended statement:
admin-groups-extended group-name;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls interface interface-name]
•
[edit logical-systems logical-system-name protocols mpls interface interface-name]
4. The LSP extended administrative groups define the set of include and exclude
constraints for an LSP and for a path’s primary and secondary paths. The extended
administrative group names must be configured for the global extended administrative
groups.
To configure extended administrative groups for an LSP, include the
admin-group-extended statement at an LSP hierarchy level:
admin-group-extended {
apply-groups group-value;
apply-groups-except group-value;
exclude group-value;
include-all group-value;
include-any group-value;
}
The admin-group-extended statement includes the following options: apply-groups,
apply-groups-except, exclude, include-all, and include-any. Each option enables you
to configure one or more extended administrative groups.
For the list of the hierarchy levels at which you can configure this statement, see the
statement summary for this statement.
5. To display the currently configured extended administrative groups, issue the show
mpls admin-groups-extended command.
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Related
Documentation
•
Configuring Administrative Groups on page 153
Configuring Preference Values for LSPs
As an option, you can configure multiple LSPs between the same pair of ingress and
egress routers. This is useful for balancing the load among the LSPs because all LSPs,
by default, have the same preference level. To prefer one LSP over another, set different
preference levels for individual LSPs. The LSP with the lowest preference value is used.
The default preference for RSVP LSPs is 7 and for LDP LSPs is 9. These preference values
are lower (more preferred) than all learned routes except direct interface routes.
To change the default preference value, include the preference statement:
preference preference;
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
Disabling Path Route Recording
The Junos implementation of RSVP supports the Record Route object, which allows an
LSP to actively record the routers through which it transits. You can use this information
for troubleshooting and to prevent routing loops. By default, path route information is
recorded. To disable recording, include the no-record statement:
no-record;
For a list of hierarchy levels at which you can include the record and no-record statements,
see the statement summary section for the statement.
Configuring Class of Service for MPLS LSPs
The following sections provide an overview of MPLS class of service (CoS) and describe
how to configure the MPLS CoS value:
•
Class of Service for MPLS Overview on page 157
•
Configuring the MPLS CoS Bits on page 158
•
Rewriting IEEE 802.1p Packet Headers with the MPLS CoS Value on page 159
Class of Service for MPLS Overview
When IP traffic enters an LSP tunnel, the ingress router marks all packets with a CoS
value, which is used to place the traffic into a transmission priority queue. On the router,
for SDH/SONET and T3 interfaces, each interface has four transmit queues. The CoS
value is encoded as part of the MPLS header and remains in the packets until the MPLS
header is removed when the packets exit from the egress router. The routers within the
LSP utilize the CoS value set at the ingress router. The CoS value is encoded by means
of the CoS bits (also known as the EXP or experimental bits). For more information, see
“Label Allocation” on page 28.
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MPLS class of service works in conjunction with the router’s general CoS functionality.
If you do not configure any CoS features, the default general CoS settings are used. For
MPLS class of service, you might want to prioritize how the transmit queues are serviced
by configuring weighted round-robin, and to configure congestion avoidance using random
early detection (RED). The general CoS features are described in the Junos OS Class of
Service Configuration Guide.
Configuring the MPLS CoS Bits
When traffic enters an LSP tunnel, the CoS bits in the MPLS header are set in one of two
ways:
•
The number of the output queue into which the packet was buffered and the packet
loss priority (PLP) bit are written into the MPLS header and are used as the packet’s
CoS value. This behavior is the default, and no configuration is required. The Junos OS
Class of Service Configuration Guide explains the IP CoS values, and summarizes how
the CoS bits are treated.
•
You set a fixed CoS value on all packets entering the LSP tunnel. A fixed CoS value
means that all packets entering the LSP receive the same class of service.
To set a fixed CoS value on all packets entering the LSP, include the class-of-service
statement:
class-of-service cos-value;
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
The CoS value set using the class-of-service statement at the [edit protocols mpls]
hierarchy level supersedes the CoS value set at the [edit class-of-service] hierarchy level
for an interface. Effectively, the CoS value configured for an LSP overrides the CoS value
set for an interface.
The CoS value can be a decimal number from 0 through 7. This number corresponds to
a 3-bit binary number. The high-order 2 bits of the CoS value select which transmit queue
to use on the outbound interface card.
The low-order bit of the CoS value is treated as the PLP bit and is used to select the RED
drop profile to use on the output queue. If the low-order bit is 0, the non-PLP drop profile
is used, and if the low-order bit is 1, the PLP drop profile is used. It is generally expected
that RED will more aggressively drop packets that have the PLP bit set. For more
information about RED and drop profiles, see the Junos OS Class of Service Configuration
Guide.
NOTE: Configuring the PLP drop profile to drop packets more aggressively
(for example, setting the CoS value from 6 to 7) decreases the likelihood of
traffic getting through.
Table 4 on page 159 summarizes how MPLS CoS values correspond to the transmit queue
and PLP bit. Note that in MPLS, the mapping between the CoS bit value and the output
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queue is hard-coded. You cannot configure the mapping for MPLS; you can configure it
only for IPv4 traffic flows, as described in the Junos OS Class of Service Configuration Guide.
Table 4: MPLS CoS Values
MPLS CoS Value
Bits
Transmit Queue
PLP Bit
0
000
0
Not set
1
001
0
Set
2
010
1
Not set
3
011
1
Set
4
100
2
Not set
5
101
2
Set
6
110
3
Not set
7
111
3
Set
Because the CoS value is part of the MPLS header, the value is associated with the
packets only as they travel through the LSP tunnel. The value is not copied back to the
IP header when the packets exit from the LSP tunnel.
Rewriting IEEE 802.1p Packet Headers with the MPLS CoS Value
For Ethernet interfaces installed on a T Series router or an M320 router with a peer
connection to an M Series router or a T Series router, you can rewrite both MPLS CoS
and IEEE 802.1p bits to a configured value (the MPLS CoS bits are also known as the EXP
or experimental bits). Rewriting these bits allows you to pass the configured value to the
Layer 2 VLAN path. To rewrite both the MPLS CoS and IEEE 802.1p bits, you must include
the EXP and IEEE 802.1p rewrite rules in the class of service interface configuration. The
EXP rewrite table is applied when you configure the IEEE 802.1p and EXP rewrite rules.
For information about how to configure the EXP and IEEE 802.1p rewrite rules, see the
Junos OS Class of Service Configuration Guide.
Configuring Adaptive LSPs
An LSP occasionally might need to reroute itself for these reasons:
•
The continuous reoptimization process is configured with the optimize-timer statement.
•
The current path has connectivity problems.
•
The LSP is preempted by another LSP configured with the priority statement and is
forced to reroute.
•
The explicit-path information for an active LSP is modified, or the LSP’s bandwidth is
increased.
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You can configure an LSP to be adaptive when it is attempting to reroute itself. When it
is adaptive, the LSP holds onto existing resources until the new path is successfully
established and traffic has been cut over to the new LSP. To retain its resources, an
adaptive LSP does the following:
•
Maintains existing paths and allocated bandwidths—This ensures that the existing
path is not torn down prematurely and allows the current traffic to continue flowing
while the new path is being set up.
•
Avoids double-counting for links that share the new and old paths—Double-counting
occurs when an intermediate router does not recognize that the new and old paths
belong to the same LSP and counts them as two separate LSPs, requiring separate
bandwidth allocations. If some links are close to saturation, double-counting might
cause the setup of the new path to fail.
By default, adaptive behavior is disabled. You can include the adaptive statement in two
different hierarchy levels.
If you specify the adaptive statement at the LSP hierarchy levels, the adaptive behavior
is enabled on all primary/secondary paths of the LSP. This means both the primary and
secondary paths share the same bandwidth on common links.
To configure adaptive behavior for all LSP paths, include the adaptive statement in the
LSP configuration:
adaptive;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name]
If you specify the adaptive statement at the [edit protocols mpls label-switched-path
lsp-name (primary | secondary) path-name] hierarchy level, adaptive behavior is enabled
only on the path on which it is specified. Bandwidth double-counting occurs between
different paths. However, if you also have the adaptive statement configured at the [edit
protocols mpls label-switched-path lsp-name] hierarchy level, it overrides the adaptive
behavior of each individual path.
To configure adaptive behavior for either the primary or secondary level, include the
adaptive statement:
adaptive;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name (primary | secondary) path-name]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
(primary | secondary) path-name]
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Configuring Priority and Preemption for LSPs
When there is insufficient bandwidth to establish a more important LSP, you might want
to tear down a less important existing LSP to free the bandwidth. You do this by
preempting the existing LSP.
Whether an LSP can be preempted is determined by two properties associated with the
LSP:
•
Setup priority—Determines whether a new LSP that preempts an existing LSP can be
established. For preemption to occur, the setup priority of the new LSP must be higher
than that of the existing LSP. Also, the act of preempting the existing LSP must produce
sufficient bandwidth to support the new LSP. That is, preemption occurs only if the
new LSP can be set up successfully.
•
Reservation priority—Determines the degree to which an LSP holds on to its session
reservation after the LSP has been set up successfully. When the reservation priority
is high, the existing LSP is less likely to give up its reservation, and hence it is unlikely
that the LSP can be preempted.
You cannot configure an LSP with a high setup priority and a low reservation priority,
because permanent preemption loops might result if two LSPs are allowed to preempt
each other. You must configure the reservation priority to be higher than or equal to the
setup priority.
The setup priority also defines the relative importance of LSPs on the same ingress router.
When the software starts, when a new LSP is established, or during fault recovery, the
setup priority determines the order in which LSPs are serviced. Higher-priority LSPs tend
to be established first and hence enjoy more optimal path selection.
To configure the LSP’s preemption properties, include the priority statement:
priority setup-priority reservation-priority;
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
Both setup-priority and reservation-priority can be a value from 0 through 7. The value 0
corresponds to the highest priority, and the value 7 to the lowest. By default, an LSP has
a setup priority of 7 (that is, it cannot preempt any other LSPs) and a reservation priority
of 0 (that is, other LSPs cannot preempt it). These defaults are such that preemption
does not happen. When you are configuring these values, the setup priority should always
be less than or equal to the hold priority.
Optimizing Signaled LSPs
Once an LSP has been established, topology or resources changes might, over time,
make the path suboptimal. A new path might have become available that is less
congested, has a lower metric, and traverses fewer hops. You can configure the router
to recompute paths periodically to determine whether a more optimal path has become
available.
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If reoptimization is enabled, an LSP can be rerouted through different paths by
constrained-path recomputations. However, if reoptimization is disabled, the LSP has a
fixed path and cannot take advantage of newly available network resources. The LSP is
fixed until the next topology change breaks the LSP and forces a recomputation.
Reoptimization is not related to failover. A new path is always computed when topology
failures occur that disrupt an established path.
Because of the potential system overhead involved, you need to control carefully the
frequency of reoptimization. Network stability might suffer when reoptimization is enabled.
By default, the optimize-timer statement is set to 0 (that is, it is disabled).
Configuring LSP optimization is meaningful only when constrained-path LSP computation
is enabled, which is the default behavior. For more information about constrained-path
LSP computation, see “Disabling Constrained-Path LSP Computation” on page 152.
To enable path reoptimization, include the optimize-timer statement:
optimize-timer seconds;
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
Once you have configured the optimize-timer statement, the reoptimization timer
continues its countdown to the configured value even if you delete the optimize-timer
statement from the configuration. The next optimization uses the new value. You can
force the Junos OS to use a new value immediately by deleting the old value, committing
the configuration, configuring the new value for the optimize-timer statement, and then
committing the configuration again.
After reoptimization is run, the result is accepted only if it meets the following criteria:
1.
The new path is not higher in IGP metric. (The metric for the old path is updated during
computation, so if a recent link metric changed somewhere along the old path, it is
accounted for.)
2. If the new path has the same IGP metric, it is not more hops away.
3. The new path does not cause preemption. (This is to reduce the ripple effect of
preemption causing more preemption.)
4. The new path does not worsen congestion overall.
The relative congestion of the new path is determined as follows:
a. The percentage of available bandwidth on each link traversed by the new path is
compared to that for the old path, starting from the most congested links.
b. For each current (old) path, the software stores the four smallest values for
bandwidth availability for the links traversed in ascending order.
c. The software also stores the four smallest bandwidth availability values for the
new path, corresponding to the links traversed in ascending order.
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d. If any of the four new available bandwidth values are smaller than any of the
corresponding old bandwidth availability values, the new path has at least one link
that is more congested than the link used by the old path. Because using the link
would cause more congestion, traffic is not switched to this new path.
e. If none of the four new available bandwidth values is smaller than the corresponding
old bandwidth availability values, the new path is less congested than the old path.
When all the above conditions are met, then:
5. If the new path has a lower IGP metric, it is accepted.
6. If the new path has an equal IGP metric and lower hop count, it is accepted.
7. If you choose least-fill as a load balancing algorithm, LSPs are load balanced as
follows:
a. The LSP is moved to a new path that is utilized at least 10% less than the current
path. This might reduce congestion on the current path by only a small amount.
For example, if an LSP with 1 MB of bandwidth is moved off a path carrying a
minimum of 200 MB, congestion on the original path is reduced by less than 1%.
b. For random or most-fill algorithms, this rule does not apply.
The following example illustrates how the least-fill load balancing algorithm works.
Figure 20: least-fill Load Balancing Algorithm Example
B
L2
L5
C
L4
L7
D
L6
L9
E
L8
L11
F
L10
L13
G
L12
H
L14
g040560
L3
L1
A
As shown in Figure 20 on page 163, there are two potential paths for an LSP to traverse
from router A to router H, the odd links from L1 through L13 and the even links from L2
through L14. Currently, the router is using the even links as the active path for the LSP.
Each link between the same two routers (for example, router A and router B) has the
same bandwidth:
•
L1, L2 = 10GE
•
L3, L4 = 1GE
•
L5, L6 = 1GE
•
L7, L8 = 1GE
•
L9, L10 = 1GE
•
L11, L12 = 10GE
•
L13, L14 = 10GE
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The 1GE links are more likely to be congested. In this example, the odd 1GE links have
the following available bandwidth:
•
L3 = 41%
•
L5 = 56%
•
L7 = 66%
•
L9 = 71%
The even 1GE links have the following available bandwidth:
•
L4 = 37%
•
L6 = 52%
•
L8 = 61%
•
L10 = 70%
Based on this information, the router would calculate the difference in available
bandwidth between the odd links and the even links as follows:
•
L4 - L3 = 41% - 37% = 4%
•
L6 - L5 = 56% - 52% = 4%
•
L8 - L7 = 66% - 61% = 5%
•
L10 - L9 = 71% - 70% = 1%
The total additional bandwidth available over the odd links is 14% (4% + 4% + 5%
+ 1%). Since 14% is greater than 10% (the least-fill algorithm minimum threshold),
the LSP is moved to the new path over the odd links from the original path using the
even links.
8. Otherwise, the new path is rejected.
You can disable the following reoptimization criteria (a subset of the criteria listed
previously):
•
If the new path has the same IGP metric, it is not more hops away.
•
The new path does not cause preemption. (This is to reduce the ripple effect of
preemption causing more preemption.)
•
The new path does not worsen congestion overall.
•
If the new path has an equal IGP metric and lower hop count, it is accepted.
To disable them, either issue the clear mpls lsp optimize-aggressive command or include
the optimize-aggressive statement:
optimize-aggressive;
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You can include this statement at the following hierarchy levels:
•
[edit protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls]
Including the optimize-aggressive statement in the configuration causes the reoptimization
procedure to be triggered more often. Paths are rerouted more frequently. It also limits
the reoptimization algorithm to the IGP metric only.
Configuring the Smart Optimize Timer
Because of network and router resource constraints, it is typically inadvisable to configure
a short interval for the optimize timer. However, under certain circumstances, it might be
desirable to reoptimize a path sooner than would normally be provided by the optimize
timer.
For example, an LSP is traversing a preferred path that subsequently fails. The LSP is
then switched to a less desirable path to reach the same destination. Even if the original
path is quickly restored, it could take an excessively long time for the LSP to use it again,
because it has to wait for the optimize timer to reoptimize the network paths. For such
situations, you might want to configure the smart optimize timer.
When you enable the smart optimize timer, an LSP is switched back to its original path
so long as the original path has been restored within 3 minutes of going down. Also, if
the original path goes down again within 60 minutes, the smart optimize timer is disabled,
and path optimization behaves as it normally does when the optimize timer alone is
enabled. This prevents the router from using a flapping link.
The smart optimize timer is dependant on other MPLS features to function properly. For
the scenario described here in which an LSP is switched to an alternate path in the event
of a failure on the original path, it is assumed that you have configured one or more of
the MPLS traffic protection features, including fast reroute, link protection, and standby
secondary paths. These features help to ensure that traffic can reach its destination in
the event of a failure. If you have not configured any sort of traffic protection for an LSP,
the smart optimize timer by itself does not ensure that traffic can reach its destination.
For more information about MPLS traffic protection, see “MPLS and Traffic Protection”
on page 46.
To configure the smart optimize timer, include the smart-optimize-timer statement:
smart-optimize-timer seconds;
You can include this statement at the following hierarchy levels:
Related
Documentation
•
[edit protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls]
•
MPLS and Traffic Protection on page 46
•
Optimizing Signaled LSPs on page 161
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Limiting the Number of Hops in LSPs
By default, each LSP can traverse a maximum of 255 hops, including the ingress and
egress routers. To modify this value, include the hop-limit statement:
hop-limit number;
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
The number of hops can be from 2 through 255. (A path with two hops consists of the
ingress and egress routers only.)
Configuring the Bandwidth Value for LSPs
Each LSP has a bandwidth value. This value is included in the sender’s Tspec field in
RSVP path setup messages. You can specify a bandwidth value in bits per second. If you
configure more bandwidth for an LSP, it should be able to carry a greater volume of
traffic. The default bandwidth is 0 bits per second.
A nonzero bandwidth requires that transit and egress routers reserve capacity along the
outbound links for the path. The RSVP reservation scheme is used to reserve this capacity.
Any failure in bandwidth reservation (such as failures at RSVP policy control or admission
control) might cause the LSP setup to fail. If there is insufficient bandwidth on the
interfaces for the transit or egress routers, the LSP is not established.
To specify a bandwidth value for a signaled LSP, include the bandwidth statement:
bandwidth bps;
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
Configuring Hot Standby of Secondary Paths
By default, secondary paths are set up only as needed. To have the system maintain a
secondary path in a hot-standby state indefinitely, include the standby statement:
standby;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name secondary]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
secondary]
The hot-standby state is meaningful only on secondary paths. Maintaining a path in a
hot-standby state enables swift cutover to the secondary path when downstream routers
on the current active path indicate connectivity problems. Although it is possible to
configure the standby statement at the [edit protocols mpls label-switched-path lsp-name
primary path-name] hierarchy level, it has no effect on router behavior.
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If you configure the standby statement at the following hierarchy levels, the hot-standby
state is activated on all secondary paths configured beneath that hierarchy level:
•
[edit protocols mpls]
•
[edit protocols mpls label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name]
The hot-standby state has two advantages:
•
It eliminates the call-setup delay during network topology changes. Call setup can
suffer from significant delays when network failures trigger large numbers of LSP
reroutes at the same time.
•
A cutover to the secondary path can be made before RSVP learns that an LSP is down.
There can be significant delays between the time the first failure is detected by protocol
machinery (which can be an interface down, a neighbor becoming unreachable, a route
becoming unreachable, or a transient routing loop being detected) and the time an
LSP actually fails (which requires a timeout of soft state information between adjacent
RSVP routers). When topology failures occur, hot-standby secondary paths can usually
achieve the smallest cutover delays with minimal disruptions to user traffic.
When the primary path is considered to be stable again, traffic is automatically switched
from the standby secondary path back to the primary path. The switch is performed no
faster than twice the retry-timer interval and only if the primary path exhibits stability
throughout the entire switch interval.
The drawback of the hot-standby state is that more state information must be maintained
by all the routers along the path, which requires overhead from each of the routers.
Damping Advertisement of LSP State Changes
When an LSP changes from being up to being down, or from down to up, this transition
takes effect immediately in the router software and hardware. However, when advertising
LSPs into IS-IS and OSPF, you may want to damp LSP transitions, thereby not advertising
the transition until a certain period of time has transpired (known as the hold time). In
this case, if the LSP goes from up to down, the LSP is not advertised as being down until
it has remained down for the hold-time period. Transitions from down to up are advertised
into IS-IS and OSPF immediately. Note that LSP damping affects only the IS-IS and
OSPF advertisements of the LSP; other routing software and hardware react immediately
to LSP transitions.
To damp LSP transitions, include the advertisement-hold-time statement:
advertisement-hold-time seconds;
seconds can be a value from 0 through 65,535 seconds. The default is 5 seconds.
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls]
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•
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CHAPTER 6
DiffServ-Aware Traffic Engineering
Configuration Guidelines
This chapter describes how to configure DiffServ-aware traffic engineering for LSPs and
multiclass LSPs:
•
DiffServ-Aware Traffic Engineering Introduction on page 170
•
DiffServ-Aware Traffic Engineering Standards on page 170
•
DiffServ-Aware Traffic Engineering Terminology on page 170
•
DiffServ-Aware Traffic Engineering Features on page 171
•
DiffServ-Aware Traffic Engineered LSPs on page 172
•
DiffServ-Aware Traffic Engineered LSPs Overview on page 172
•
DiffServ-Aware Traffic Engineered LSPs Operation on page 173
•
Multiclass LSPs on page 173
•
Multiclass LSP Overview on page 174
•
Establishing a Multiclass LSP on the Differentiated Services Domain on page 174
•
Configuring Routers for DiffServ-Aware Traffic Engineering on page 175
•
Bandwidth Oversubscription Overview on page 179
•
LSP Size Oversubscription on page 180
•
Link Size Oversubscription on page 180
•
Class Type Oversubscription and Local Oversubscription Multipliers on page 180
•
Class Type Bandwidth and the LOM on page 181
•
LOM Calculation for the MAM and Extended MAM Bandwidth Models on page 181
•
LOM Calculation for the Russian Dolls Bandwidth Model on page 182
•
Example: LOM Calculation on page 182
•
Configuring the Bandwidth Subscription Percentage for LSPs on page 183
•
Configuring LSPs for DiffServ-Aware Traffic Engineering on page 185
•
Configuring Multiclass LSPs on page 188
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DiffServ-Aware Traffic Engineering Introduction
Differentiated Services (DiffServ)-aware traffic engineering provides a way to guarantee
a specified level of service over an MPLS network. The routers providing DiffServ-aware
traffic engineering are part of a differentiated services network domain. All routers
participating in a differentiated services domain must have DiffServ-aware traffic
engineering enabled.
To help ensure that the specified service level is provided, it is necessary to ensure that
no more than the amount of traffic specified is sent over the differentiated services
domain. You can accomplish this goal by configuring a policer to police or rate-limit the
volume of traffic transiting the differentiated service domain. For more information about
how to configure policers for label-switched paths (LSPs), see “Configuring Policers for
LSPs” on page 226.
This feature can help to improve the quality of Internet services such as voice over IP
(VoIP). It also makes it possible to better emulate an Asynchronous Transfer Mode (ATM)
circuit over an MPLS network.
DiffServ-Aware Traffic Engineering Standards
The following RFCs provide information on DiffServ-aware traffic engineering and
multiclass LSPs:
•
RFC 3270, Multi-Protocol Label Switching (MPLS) Support of Differentiated Services
•
RFC 3564, Requirements for Support of Differentiated Services-aware MPLS Traffic
Engineering
•
RFC 4124, Protocol Extensions for Support of Differentiated-Service-Aware MPLS Traffic
Engineering
•
RFC 4125, Maximum Allocation Bandwidth Constraints Model for Diff-Serv-aware MPLS
Traffic Engineering
•
RFC 4127, Russian Dolls Bandwidth Constraints Model for Diff-Serv-aware MPLS
These RFCs are available on the IETF website at http://www.ietf.org/.
DiffServ-Aware Traffic Engineering Terminology
B
Bandwidth model
The bandwidth model determines the values of the available bandwidth advertised by the
interior gateway protocols (IGPs).
C
CAC
Call admission control (CAC) checks to ensure there is adequate bandwidth on the path before
the LSP is established. If the bandwidth is insufficient, the LSP is not established and an error
is reported.
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Class type
A collection of traffic flows that is treated equivalently in a differentiated services domain. A
class type maps to a queue and is much like a class-of-service (CoS) forwarding class in
concept. It is also known as a traffic class.
D
Differentiated Services
Differentiated Services make it possible to give different treatment to traffic based on the EXP
bits in the MPLS header. Traffic must be marked appropriately and CoS must be configured.
Differentiated Services
The routers in a network that have Differentiated Services enabled.
domain
DiffServ-aware traffic
engineering
A type of constraint-based routing. It can enforce different bandwidth constraints for different
classes of traffic. It can also do CAC on each traffic engineering class when an LSP is
established.
M
MAM
The maximum allocation bandwidth constraint model divides the available bandwidth between
the different classes. Sharing of bandwidth between the class types is not allowed.
Multiclass LSP
A multiclass LSP functions like a standard LSP, but it also allows you to reserve bandwidth
from multiple class types. The EXP bits of the MPLS header are used to distinguish between
class types.
R
RDM
The Russian dolls bandwidth constraint model makes efficient use of bandwidth by allowing
the class types to share bandwidth.
T
Traffic engineering
A paired class type and priority.
class
Traffic engineering
class map
A map between the class types, priorities, and traffic engineering classes. The traffic engineering
class mapping must be consistent across the Differentiated Services domain.
DiffServ-Aware Traffic Engineering Features
DiffServ-aware traffic engineering provides the following features:
•
Traffic engineering at a per-class level rather than at an aggregate level
•
Different bandwidth constraints for different class types (traffic classes)
•
Different queuing behaviors per class, allowing the router to forward traffic based on
the class type
In comparison, standard traffic engineering does not consider CoS, and it completes its
work on an aggregate basis across all Differentiated Service classes.
DiffServ-aware traffic engineering provides the following advantages:
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•
Traffic engineering can be performed on a specific class type instead of at the aggregate
level.
•
Bandwidth constraints can be enforced on each specific class type.
•
It forwards traffic based on the EXP bits.
This makes it possible to guarantee service and bandwidth across an MPLS network.
With DiffServ-aware traffic engineering, among other services, you can provide ATM
circuit emulation, VoIP, and a guaranteed bandwidth service.
The following describes how the IGP, Constrained Shortest Path First (CSPF), and RSVP
participate in DiffServ-aware traffic engineering:
•
The IGP can advertise the unreserved bandwidth for each traffic engineering class to
the other members of the differentiated services domain. The traffic engineering
database stores this information.
•
A CSPF calculation is performed considering the bandwidth constraints for each class
type. If all the constraints are met, the CSPF calculation is considered successful.
•
When RSVP signals an LSP, it requests bandwidth for specified class types.
DiffServ-Aware Traffic Engineered LSPs
A DiffServ-aware traffic engineered LSP is an LSP configured to reserve bandwidth for
one of the supported class types and to carry traffic for that class type. The following
sections discuss this type of LSPs:
•
DiffServ-Aware Traffic Engineered LSPs Overview on page 172
•
DiffServ-Aware Traffic Engineered LSPs Operation on page 173
DiffServ-Aware Traffic Engineered LSPs Overview
A DiffServ-aware traffic engineered LSP is an LSP configured with a bandwidth reservation
for a specific class type. This LSP can carry traffic for a single class type. On the packets,
the class type is specified by the EXP bits (also known as the class-of-service bits) and
the per-hop behavior (PHB) associated with the EXP bits. The mapping between the
EXP bits and the PHB is static, rather than being signaled in RSVP.
The class type must be configured consistently across the Differentiated Services domain,
meaning the class type configuration must be consistent from router to router in the
network. You can unambiguously map a class type to a queue. On each node router, the
class-of-service queue configuration for an interface translates to the available bandwidth
for a particular class type on that link.
For more information about topics related to LSPs and DiffServ-aware traffic engineering,
see the following:
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•
For forwarding classes and class of service, see the Junos OS Class of Service Configuration
Guide.
•
For EXP bits, see “Label Allocation” on page 28.
•
For differentiated services, see RFC 3270, Multi-Protocol Label Switching (MPLS)
Support of Differentiated Services.
•
For information about how the IGPs and RSVP have been modified to support
Differentiated Services-aware MPLS traffic engineering, see RFC 4124, Protocol
Extensions for Support of Differentiated-Service-Aware MPLS Traffic Engineering.
DiffServ-Aware Traffic Engineered LSPs Operation
When configuring a DiffServ-aware traffic engineered LSP, you specify the class type
and the bandwidth associated with it. The following occurs when an LSP is established
with bandwidth reservation from a specific class type:
1.
The IGPs advertise how much unreserved bandwidth is available for the traffic
engineering classes.
2. When calculating the path for an LSP, CSPF is used to ensure that the bandwidth
constraints are met for the class type carried by the LSP at the specified priority level.
CSPF also checks to ensure that the bandwidth model is configured consistently on
each router participating in the LSP. If the bandwidth model is inconsistent, CSPF
does not compute the path (except for LSPs from class type ct0).
3. Once a path is found, RSVP signals the LSP using the Classtype object in the path
message. At each node in the path, the available bandwidth for the class types is
adjusted as the path is set up.
An LSP that requires bandwidth from a particular class (except class type ct0) cannot
be established through routers that do not understand the Classtype object. Preventing
the use of routers that do not understand the Classtype object helps to ensure consistency
throughout the Differentiated Services domain by preventing the LSP from using a router
that cannot support Differentiated Services.
By default, LSPs are signaled with setup priority 7 and holding priority 0. An LSP configured
with these values cannot preempt another LSP at setup time and cannot be preempted.
It is possible to have both LSPs configured for DiffServ-aware traffic engineering and
regular LSPs configured at the same time on the same physical interfaces. For this type
of heterogeneous environment, regular LSPs carry best-effort traffic by default. Traffic
carried in the regular LSPs must have the correct EXP settings (either by remarking the
EXP settings or by assuming that the traffic arrived with the correct EXP settings from
the upstream router).
Multiclass LSPs
Multiclass LSPs function like standard LSPs, but they also allow you to configure multiple
class types with guaranteed bandwidth. The EXP bits of the MPLS header are used to
distinguish between class types. Multiclass LSPs can be configured for a variety of
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purposes. For example, you can configure a multiclass LSP to emulate the behavior of
an ATM circuit. An ATM circuit can provide service-level guarantees to a class type. A
multiclass LSP can provide a similar guaranteed level of service.
The following sections discuss multiclass LSPs:
•
Multiclass LSP Overview on page 174
•
Establishing a Multiclass LSP on the Differentiated Services Domain on page 174
Multiclass LSP Overview
A multiclass LSP is an LSP that can carry several class types. One multiclass LSP can be
used to support up to four class types. On the packets, the class type is specified by the
EXP bits (also known as the class-of-service bits) and the per-hop behavior (PHB)
associated with the EXP bits. The mapping between the EXP bits and the PHB is static,
rather than being signaled in RSVP.
Once a multiclass LSP is configured, traffic from all of the class types can:
•
Follow the same path
•
Be rerouted along the same path
•
Be taken down at the same time
Class types must be configured consistently across the Differentiated Services domain,
meaning the class type configuration must be consistent from router to router in the
network.
You can unambiguously map a class type to a queue. On each node router, the CoS queue
configuration for an interface translates to the available bandwidth for a particular class
type on that link.
The combination of a class type and a priority level forms a traffic engineering class. The
IGPs can advertise up to eight traffic engineering classes for each link.
For more information about the EXP bits, see “Label Allocation” on page 28.
For more information about forwarding classes, see the Junos OS Class of Service
Configuration Guide.
Establishing a Multiclass LSP on the Differentiated Services Domain
The following occurs when a multiclass LSP is established on the differentiated services
domain:
1.
The IGPs advertise how much unreserved bandwidth is available for the traffic
engineering classes.
2. When calculating the path for a multiclass LSP, CSPF is used to ensure that the
constraints are met for all the class types carried by the multiclass LSP (a set of
constraints instead of a single constraint).
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3. Once a path is found, RSVP signals the LSP using an RSVP object in the path message.
At each node in the path, the available bandwidth for the class types is adjusted as
the path is set up. The RSVP object is a hop-by-hop object. Multiclass LSPs cannot
be established through routers that do not understand this object. Preventing routers
that do not understand the RSVP object from carrying traffic helps to ensure
consistency throughout the differentiated services domain by preventing the multiclass
LSP from using a router that is incapable of supporting differentiated services.
By default, multiclass LSPs are signaled with setup priority 7 and holding priority 0. A
multiclass LSP configured with these values cannot preempt another LSP at setup time
and cannot be preempted.
It is possible to have both multiclass LSPs and regular LSPs configured at the same time
on the same physical interfaces. For this type of heterogeneous environment, regular
LSPs carry best-effort traffic by default. Traffic carried in the regular LSPs must have the
correct EXP settings.
Configuring Routers for DiffServ-Aware Traffic Engineering
To configure DiffServ-aware traffic engineering, include the diffserv-te statement:
diffserv-te {
bandwidth-model {
extended-mam;
mam;
rdm;
}
te-class-matrix {
traffic-class {
tenumber {
priority priority;
traffic-class ctnumber priority priority;
}
}
}
}
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls]
You must include the diffserv-te statement in the configuration on all routers participating
in the Differentiated Services domain. However, you are not required to configure the
traffic engineering class matrix (by including the te-class-matrix statement at the [edit
protocols mpls diffserv-te] or [edit logical-systems logical-system-name protocols mpls
diffserv-te] hierarchy level).
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NOTE: To prevent the possibility of an incorrect configuration when migrating
to Diffserv-aware traffic engineering, a policy control failure error might be
triggered if there is conflict between the old LSPs and the newly configured
TE-class matrix.
An old node might request an LSP with setup and hold priorities in such a
way that the combination of the ct0 class and the priority does not match
with the configured TE-class matrix. All LSPs on the router that are configured
prior to configuring diffserv-aware traffic engineering are designated as being
from class ct0.
The error appears in the RSVP tracing logs as a Session preempted error. For
the router where the error originates, the error could appear as follows:
Jun 17 16:35:59 RSVP error for session 10.255.245.6(port/tunnel ID 31133)
Proto 0: (class ct0, priority 2) is not a valid TE-class Jun 17
16:35:59 RSVP originate PathErr 192.168.37.22->192.168.37.23 Session
preempted
For the router receiving the error, the error can appear as follows:
Jun 17 16:37:51 RSVP recv PathErr 192.168.37.22->192.168.37.23 Session
preempted LSP to-f(2/31133)
To configure DiffServ-aware traffic engineering, complete the procedures in the following
sections:
•
Configuring the Bandwidth Model on page 176
•
Configuring Traffic Engineering Classes on page 177
•
Configuring Class of Service for DiffServ-Aware Traffic Engineering on page 178
Configuring the Bandwidth Model
You must configure a bandwidth model on all routers participating in the Differentiated
Services domain. The bandwidth models available are MAM, extended MAM, and RDM:
•
Maximum allocation bandwidth constraints model (MAM)—Defined in RFC 4125,
Maximum Allocation Bandwidth Constraints Model for Diffserv-aware MPLS Traffic
Engineering.
•
Extended MAM—A proprietary bandwidth model that behaves much like standard
MAM. If you configure multiclass LSPs, you must configure the extended MAM
bandwidth model.
•
Russian-dolls bandwidth allocation model (RDM)—Makes efficient use of bandwidth
by allowing the class types to share bandwidth. RDM is defined in RFC 4127, Russian
Dolls Bandwidth Constraints Model for Diffserv-aware MPLS Traffic Engineering.
To configure a bandwidth model, include the bandwidth-model statement and specify
one of the bandwidth model options:
bandwidth-model {
extended-mam;
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mam;
rdm;
}
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls diffserv-te]
•
[edit logical-systems logical-system-name protocols mpls diffserv-te]
NOTE: If you change the bandwidth model on an ingress router, all the
LSPs enabled on the router are taken down and resignaled.
Configuring Traffic Engineering Classes
Configuring traffic engineering classes is optional. Table 5 on page 177 shows the default
values for everything in the traffic engineering class matrix. The default mapping is
expressed in terms of the default forwarding classes defined in the CoS configuration.
Table 5: Default Values for the Traffic Engineering Class Matrix
Traffic Engineering Class
Class Type
Queue
Priority
te0
ct0
0
7
te1
ct1
1
7
te2
ct2
2
7
te3
ct3
3
7
te4
ct0
0
0
te5
ct1
1
0
te6
ct2
2
0
te7
ct3
3
0
If you want to override the default mappings, you can configure traffic engineering classes
0 through 7. For each traffic engineering class, you configure a class type (or queue) from
0 through 3. For each class type, you configure a priority from 0 through 7.
To configure traffic engineering classes explicitly, include the te-class-matrix statement:
te-class-matrix {
tenumber {
priority priority;
traffic-class {
ctnumber priority priority;
}
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}
}
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls diffserv-te]
•
[edit logical-systems logical-system-name protocols mpls diffserv-te]
The following example shows how to configure traffic engineering class te0 with class
type ct1 and a priority of 4:
[edit protocols mpls diffserv-te]
te-class-matrix {
te0 traffic-class ct1 priority 4;
}
NOTE: If you explicitly configure a value for one of the traffic engineering
classes, all the default values in the traffic engineering class matrix are
dropped.
When you explicitly configure traffic engineering classes, you must also
configure a bandwidth model; otherwise, the configuration commit operation
fails.
Requirements and Limitations for the Traffic Engineering Class Matrix
When you configure a traffic engineering class matrix, be aware of the following
requirements and limitations:
•
A mapping configuration is local and affects only the router on which it is configured.
It does not affect other systems participating in the differentiated services domain.
However, for a Differentiated Services domain to function properly, you need to
configure the same traffic engineering class matrix on all the routers participating in
the same domain.
•
When explicitly configuring traffic engineering classes, you must configure the classes
in sequence (te0, te1, te2, te3, and so on); otherwise, the configuration commit operation
fails.
The first traffic engineering class you configure must be te0; otherwise, the configuration
commit operation fails.
Configuring Class of Service for DiffServ-Aware Traffic Engineering
To configure DiffServ-aware traffic engineering, you must also configure class of service.
The following example illustrates a class-of-service configuration that would allocate
25 percent of the link bandwidth to each class:
class-of-service {
interfaces {
all {
scheduler-map simple-map;
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}
}
scheduler-maps {
simple-map {
forwarding-class assured-forwarding scheduler simple_sched;
forwarding-class best-effort scheduler simple_sched;
forwarding-class network-control scheduler simple_sched;
forwarding-class expedited-forwarding scheduler simple_sched;
}
}
schedulers {
simple_sched {
transmit-rate percent 25;
buffer-size percent 25;
}
}
}
For more information on how to configure class of service, see the Junos OS Class of Service
Configuration Guide.
Bandwidth Oversubscription Overview
LSPs are established with bandwidth reservations configured for the maximum amount
of traffic you expect to traverse the LSP. Not all LSPs carry the maximum amount of
traffic over their links at all times. For example, even if the bandwidth for link A has been
completely reserved, actual bandwidth might still be available but not currently in use.
This excess bandwidth can be used by allowing other LSPs to also use link A,
oversubscribing the link. You can oversubscribe the bandwidth configured for individual
class types or specify a single value for all of the class types using an interface.
You can use oversubscription to take advantage of the statistical nature of traffic patterns
and to permit higher utilization of links.
The following examples describe how you might use bandwidth oversubscription and
undersubscription:
•
Use oversubscription on class types where peak periods of traffic do not coincide in
time.
•
Use oversubscription of class types carrying best-effort traffic. You take the risk of
temporarily delaying or dropping traffic in exchange for making better utilization of
network resources.
•
Give different degrees of oversubscription or undersubscription of traffic for the different
class types. For instance, you configure the subscription for classes of traffic as follows:
•
Best effort—ct0 1000
•
Voice—ct3 1
When you undersubscribe a class type for a multiclass LSP, the total demand of all RSVP
sessions is always less than the actual capacity of the class type. You can use
undersubscription to limit the utilization of a class type.
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The bandwidth oversubscription calculation occurs on the local router only. Because no
signaling or other interaction is required from other routers in the network, the feature
can be enabled on individual routers without being enabled or available on other routers
which might not support this feature. Neighboring routers do not need to know about
the oversubscription calculation, they rely on the IGP.
The following sections describe the types of bandwidth oversubscription available in the
Junos OS:
•
LSP Size Oversubscription on page 180
•
Link Size Oversubscription on page 180
•
Class Type Oversubscription and Local Oversubscription Multipliers on page 180
LSP Size Oversubscription
For LSP size oversubscription, you simply configure less bandwidth than the peak rate
expected for the LSP. You also might need to adjust the configuration for automatic
policers. Automatic policers manage the traffic assigned to an LSP, ensuring that it does
not exceed the configured bandwidth values. LSP size oversubscription requires that the
LSP can exceed its configured bandwidth allocation.
Policing is still possible. However, the policer must be manually configured to account
for the maximum bandwidth planned for the LSP, rather than for the configured value.
Link Size Oversubscription
You can increase the maximum reservable bandwidth on the link and use the inflated
values for bandwidth accounting. Use the subscription statement to oversubscribe the
link. The configured value is applied to all class type bandwidth allocations on the link.
For more information about link size oversubscription, see “Configuring the Bandwidth
Subscription Percentage for LSPs” on page 183.
Class Type Oversubscription and Local Oversubscription Multipliers
Local oversubscription multipliers (LOMs) allow different oversubscription values for
different class types. LOMs are useful for networks where the oversubscription ratio
needs to be configured differently on different links and where oversubscription values
are required for different classes. You might use this feature to oversubscribe class types
handling best-effort traffic, but use no oversubscription for class types handling voice
traffic. An LOM is calculated locally on the router. No information related to an LOM is
signaled to other routers in the network.
An LOM is configurable on each link and for each class type. The per-class type LOM
allows you to increase or decrease the oversubscription ratio. The per-class-type LOM
is factored into all local bandwidth accounting for admission control and IGP
advertisement of unreserved bandwidths.
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The LOM calculation is tied to the bandwidth model (MAM, extended MAM, and Russian
dolls) used, because the effect of oversubscription across class types must be accounted
for accurately.
NOTE: All LOM calculations are performed by the Junos OS and require no
user intervention.
The formulas related to the oversubscription of class types are described in
the following sections:
•
Class Type Bandwidth and the LOM on page 181
•
LOM Calculation for the MAM and Extended MAM Bandwidth Models on
page 181
•
LOM Calculation for the Russian Dolls Bandwidth Model on page 182
•
Example: LOM Calculation on page 182
Class Type Bandwidth and the LOM
The following formula expresses the relationship between the bandwidth of the class
type and the LOM. The normalized bandwidth of the class type (N ) is equal to the
B
reserved bandwidth of the class type (R ) divided by the LOM of the class type (L ):
B
N = R /L
B
B
C
C
When calculating available bandwidth, you need to subtract the normalized bandwidth
from the relevant bandwidth constraint.
NOTE: When using an LOM, values advertised for the available bandwidth
might be larger than the bandwidth constraint values. However, the values
advertised in the maximum link bandwidth advertisement are not affected
by local oversubscription.
LOM Calculation for the MAM and Extended MAM Bandwidth Models
The following formulas show how the LOM is calculated for the MAM and extended MAM
bandwidth models.
Unreserved TE-Class(i) = LOMc x [ BCc – SUM ( Normalized (CTc, q) ) ] for q <= p
Or
Unreserved TE-Class(i) = ( LOMc x BCc ) – SUM ( Reserved (CTc, q) ) for q <= p
where:
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•
LOMc—LOM for class type c.
•
BCc—Bandwidth constraint for class type c.
•
CTc—Class type c.
•
TE-Class(i) <––> ( CTc , preemption p ) in the configured TE-Class mapping.
LOM Calculation for the Russian Dolls Bandwidth Model
The following formulas show how the LOM is calculated for the Russian dolls bandwidth
model:
Unreserved TE-Class (i) = LOMc x MIN [
[ BCc - SUM ( Normalized (CTb, q) ) ] for q <= p and c <= b <= 7,
...
[ BC0 - SUM ( Normalized (CTb, q) ) ] for q <= p and 0 <= b <= 7,
]
where:
•
LOMc—LOM for class type c.
•
BCc—Bandwidth constraint for class type c.
•
TE-Class(i) <– –>(CTc , preemption p ) in the configured TE-Class mapping.
Note that the impact of an LSP on the unreserved bandwidth of a class type does not
depend only on the LOM for that class type—it also depends on the LOM for the class
type of the LSP.
Example: LOM Calculation
The following example illustrates how an LOM calculation is made for four classes of
traffic: ct0, ct1, ct2, and ct3.
The class types have been assigned the following values:
ct0 = 40
ct1 = 30
ct2 = 20
ct3 = 10
These class type values yield the following bandwidth constraints:
BC0 = (ct3 + ct2 + ct1 + ct0) = 100
BC1 = (ct3 + ct2 + ct1) = 60
BC2 = (ct3 + ct2) = 30
BC3 = (ct3) = 10
LSPs from class type ct0 can take up to 100 percent of bandwidth on the link. LSPs from
class type ct1 can take up to 60 percent of the bandwidth on the link, and so on.
If you assume for this example that the class types have the following LOM values:
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LOM(ct0) = 8
LOM(ct1) = 4
LOM(ct2) = 2
LOM(ct3) = 1
In the absence of any other reservation, LSPs from class type ct0 can take up to
800 percent of the available bandwidth (8 x 100 = 800). In the absence of any other
reservation, LSPs from class type ct1 can take up to 240 percent of the available
bandwidth (4 x 60 = 240). and so on.
The maximum amount of bandwidth that can be reserved is:
ct0 = LOM(ct0) x BC0 = 800
ct1 = LOM(ct1) x BC1 = 240
ct2 = LOM(ct2) x BC2 = 60
ct3 = LOM(ct3) x BC3 = 10
For the undersubscribed class type ct3, the maximum reservable bandwidth is the same
as the bandwidth constraint. For the overbooked class types, these values are not the
values of the bandwidth constraint-taking into account the oversubscription for each
class type separately. The oversubscription per class type in the sum is not taken into
account because ultimately the entire bandwidth constraint can be filled with the
bandwidth reservation of just one class type, so you have to account for that class type’s
bandwidth oversubscription only.
When calculating the available bandwidth for CTc, you need to express reservations from
other classes as if they were from CTc. The reservation from class ctx is normalized with
the LOM of ctx, but it is then multiplied by the LOM of CTc.
For the previous example, assume that LSP1 has class type ct3 configured with bandwidth
of 10 and a priority of 0.
The values for the reservable bandwidth will be:
ct0 = 8 x (100 - 10) = 720
ct1 = 4 x min((100-10), (60-10)) = 200
ct2 = 2 x min((100-10), (60-10), (30-10)) = 40
ct3 = 1 x min((100-10), (60-10), (30-10), (10-10)) = 0
These numbers can be rationalized as follows: the normalized reservation is 10 percent.
If this bandwidth came from class type ct0, it would be equivalent to an overbooked
reservation of 80 percent. You can see that 720 percent (800 – 80 = 720) of the bandwidth
remains available for other LSPs.
Configuring the Bandwidth Subscription Percentage for LSPs
By default, RSVP allows all of a class type’s bandwidth (100 percent) to be used for
RSVP reservations. When you oversubscribe a class type for a multiclass LSP, the
aggregate demand of all RSVP sessions is allowed to exceed the actual capacity of the
class type.
If you want to oversubscribe or undersubscribe all of the class types on an interface using
the same percentage bandwidth, configure the percentage using the subscription
statement:
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subscription percentage;
For a list of hierarchy levels at which you can include this statement, see the statement
summary section.
To undersubscribe or oversubscribe the bandwidth for each class type, configure a
percentage for each class type (ct0, ct1, ct2, and ct3) option for the subscription statement.
When you oversubscribe a class type, an LOM is applied to calculate the actual bandwidth
reserved. See “Class Type Oversubscription and Local Oversubscription Multipliers” on
page 180 for more information.
subscription {
ct0 percentage;
ct1 percentage;
ct2 percentage;
ct3 percentage;
}
For a list of hierarchy levels at which you can include this statement, see the statement
summary section.
percentage is the percentage of class type bandwidth that RSVP allows to be used for
reservations. It can be a value from 0 through 65,000 percent. If you specify a value
greater than 100, you are oversubscribing the interface or class type.
The value you configure when you oversubscribe a class type is a percentage of the class
type bandwidth that can actually be used. The default subscription value is 100 percent.
You can use the subscription statement to disable new RSVP sessions for one or more
class types. If you configure a percentage of 0, no new sessions (including those with
zero bandwidth requirements) are permitted for the class type.
Existing RSVP sessions are not affected by changing the subscription factor. To clear an
existing session, issue the clear rsvp session command. For more information on the clear
rsvp session command, see the Junos OS Routing Protocols and Policies Command Reference.
Constraints on Configuring Bandwidth Subscription
Be aware of the following issues when configuring bandwidth subscription:
184
•
If you configure bandwidth constraints at the [edit class-of-service interface
interface-name] hierarchy level, they override any bandwidth configuration you specify
at the [edit protocols rsvp interface interface-name bandwidth] hierarchy level for
Diffserv-TE. Also note that either of the CoS or RSVP bandwidth constraints can override
the interface hardware bandwidth constraints.
•
If you configure a bandwidth subscription value for a specific interface that differs from
the value configured for all interfaces (by including different values for the subscription
statement at the [edit protocols rsvp interface interface-name] and [edit protocols rsvp
interface all] hierarchy levels), the interface-specific value is used for that interface.
•
You can configure subscription for each class type only if you also configure a bandwidth
model. If no bandwidth model is configured, the commit operation fails with the
following error message:
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user@host# commit check
[edit protocols rsvp interface all]
'subscription'
RSVP: Must have a diffserv-te bandwidth model configured when configuring
subscription per traffic class.
error: configuration check-out failed
•
You cannot include the subscription statement both in the configuration for a specific
class type and the configuration for the entire interface. The commit operation fails
with the following error message:
user@host# commit check
[edit protocols rsvp interface all]
'subscription'
RSVP: Cannot configure both link subscription and per traffic class
subscription.
error: configuration check-out failed
Configuring LSPs for DiffServ-Aware Traffic Engineering
You must configure the Differentiated Services domain (see “Configuring Routers for
DiffServ-Aware Traffic Engineering” on page 175) before you can enable DiffServ-aware
traffic engineering for LSPs. The Differentiated Services domain provides the underlying
class types and corresponding traffic engineering classes that you reference in the LSP
configuration. The traffic engineering classes must be configured consistently on each
router participating in the Differentiated Services domain for the LSP to function properly.
NOTE: You must configure either MAM or RDM as the bandwidth model when
you configure DiffServ-aware traffic engineering for LSPs. See “Configuring
the Bandwidth Model” on page 176.
The actual data transmitted over this Differentiated Services domain is carried by an
LSP. Each LSP relies on the EXP bits of the MPLS packets to enable DiffServ-aware traffic
engineering. Each LSP can carry traffic for a single class type.
All the routers participating in the LSP must be Juniper Networks routers running Junos
OS Release 6.3 or later. The network can include routers from other vendors and Juniper
Networks routers running earlier versions of the Junos OS. However, the DiffServ-aware
traffic engineering LSP cannot traverse these routers.
NOTE: You cannot simultaneously configure multiclass LSPs and
DiffServ-aware traffic engineering LSPs on the same router.
To enable DiffServ-aware traffic engineering for LSPs, you need to configure the following:
•
Configuring Class of Service for the Interfaces on page 186
•
Configuring IGP on page 186
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•
Configuring Traffic-Engineered LSPs on page 186
•
Configuring Policing for LSPs on page 187
•
Configuring Fast Reroute for Traffic-Engineered LSPs on page 187
Configuring Class of Service for the Interfaces
The existing class-of-service (CoS) infrastructure ensures that traffic that is consistently
marked receives the scheduling guarantees for its class. The classification, marking, and
scheduling necessary to accomplish this are configured using the existing Junos OS CoS
features.
NOTE: The Junos OS does not support CoS on ATM interfaces.
For information about how to configure CoS, see the Junos OS Class of Service Configuration
Guide.
Configuring IGP
You can configure either IS-IS or OSPF as the IGP. The IS-IS and OSPF configurations
for routers supporting LSPs are standard. For information about how to configure these
protocols, see the Junos OS Routing Protocols Configuration Guide.
Configuring Traffic-Engineered LSPs
You configure an LSP by using the standard LSP configuration statements and procedures.
To configure DiffServ-aware traffic engineering for the LSP, specify a class type bandwidth
constraint by including the bandwidth statement:
label-switched-path lsp-name {
bandwidth {
ctnumber bps;
}
}
For a list of hierarchy levels at which you can include the bandwidth statement, see the
statement summary sections for this statement.
If you do not specify a bandwidth for a class type, ct0 is automatically specified as the
queue for the LSP. You can configure only one class type for each LSP, unlike multiclass
LSPs.
The class type statements specify bandwidth (in bits per second) for the following
classes:
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•
ct0—Bandwidth reserved for class 0
•
ct1—Bandwidth reserved for class 1
•
ct2—Bandwidth reserved for class 2
•
ct3—Bandwidth reserved for class 3
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You can configure setup and holding priorities for an LSP, but the following restrictions
apply:
•
The combination of class and priority must be one of the configured traffic engineering
classes. The default setup priority is 7 and the default holding priority is 0.
•
Configuring an invalid combination of class type and priority causes the commit
operation to fail.
•
Automatic bandwidth allocation is not supported. If you configure automatic bandwidth
allocation, the commit operation fails.
•
LSPs configured with the bandwidth statement but without specifying a class type use
the default class type ct0.
•
For migration issues, see Internet draft draft-ietf-tewg-diff-te-proto-07.txt.
Configuring Policing for LSPs
Policing allows you to control the amount of traffic forwarded through a particular LSP.
Policing helps to ensure that the amount of traffic forwarded through an LSP never
exceeds the requested bandwidth allocation. You can configure multiple policers for
each LSP.
For information about how to configure a policer for an LSP, see “Configuring Policers
for LSPs” on page 226.
Configuring Fast Reroute for Traffic-Engineered LSPs
You can configure fast reroute for traffic engineered LSPs (LSPs carrying a single class
of traffic). It is also possible to reserve bandwidth on the detour path for the class of
traffic when fast reroute is enabled. The same class type number is used for both the
traffic engineered LSP and its detour.
If you configure the router to reserve bandwidth for the detour path, a check is made to
ensure that the link is capable of handling DiffServ-aware traffic engineering and for CoS
capability before accepting it as a potential detour path. Unsupported links are not used.
You can configure the amount of bandwidth to reserve for detours using either the
bandwidth statement or the bandwidth-percent statement. You can only configure one
these statements at a time. If you do not configure either the bandwidth statement or
the bandwidth-percent statement, the default setting is to not reserve bandwidth for the
detour path (the bandwidth guarantee will be lost if traffic is switched to the detour).
When you configure the bandwidth statement, you can specify the specific amount of
bandwidth (in bits per second [bps]) you want to reserve for the detour path. For
information, see “Configuring Fast Reroute” on page 134.
The bandwidth-percent statement allows you to specify the bandwidth of the detour
path as a percentage of the bandwidth configured for the protected path. For example,
if you configure 100 millions bps of bandwidth for the protected path and configure 20
for the bandwidth-percent statement, the detour path will have 20 million bps of
bandwidth reserved for its use.
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To configure the percent of bandwidth used by the detour path based on the bandwidth
of the protected path, include the bandwidth-percent statement:
bandwidth-percent percentage;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name fast-reroute]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path
lsp-name fast-reroute]
Configuring Multiclass LSPs
A multiclass LSP is an LSP configured to reserve bandwidth for multiple class types and
also carries the traffic for these class types. The differentiated service behavior is
determined by the EXP bits.
You must configure the Differentiated Services domain (see “Configuring Routers for
DiffServ-Aware Traffic Engineering” on page 175) before you can enable a multiclass LSP.
The Differentiated Services domain provides the underlying class types and corresponding
traffic engineering classes that you reference in a multiclass LSP configuration. The traffic
engineering classes must be configured consistently on each router participating in the
Differentiated Services domain for the multiclass LSP to function properly.
NOTE: You must configure extended MAM as the bandwidth model when
you configure multiclass LSPs. See “Configuring the Bandwidth Model” on
page 176.
All the routers participating in a multiclass LSP must be Juniper Networks routers running
Junos OS Release 6.2 or later. The network can include routers from other vendors and
Juniper Networks routers running earlier versions of the Junos OS. However, the multiclass
LSP cannot traverse these routers.
To enable multiclass LSPs, you need to configure the following:
•
Configuring Class of Service for the Interfaces on page 188
•
Configuring the IGP on page 189
•
Configuring Class-Type Bandwidth Constraints for Multiclass LSPs on page 189
•
Configuring Policing for Multiclass LSPs on page 190
•
Configuring Fast Reroute for Multiclass LSPs on page 190
Configuring Class of Service for the Interfaces
The existing class-of-service infrastructure ensures that traffic that is consistently marked
receives the scheduling guarantees for its class. The classification, marking, and scheduling
necessary to consistently mark traffic are configured with the existing Junos OS CoS
features.
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NOTE: The Junos OS does not support ATM interfaces.
For information about how to configure CoS, see the Junos OS Class of Service Configuration
Guide.
Configuring the IGP
You can configure either IS-IS or OSPF. The IS-IS and OSPF configurations for routers
supporting multiclass LSPs are standard. For information about how to configure these
protocols, see the Junos OS Routing Protocols Configuration Guide.
Configuring Class-Type Bandwidth Constraints for Multiclass LSPs
You configure a multiclass LSP by using the standard LSP configuration statements and
procedures. To configure an LSP as a multiclass LSP, specify the class type bandwidth
constraints by including the bandwidth statement:
bandwidth {
ct0 bps;
ct1 bps;
ct2 bps;
ct3 bps;
}
For a list of hierarchy levels at which you can include the bandwidth statement, see the
statement summary sections for these statements.
The class type statements specify bandwidth (in bits per second) for the following
classes:
•
ct0—Bandwidth reserved for class 0
•
ct1—Bandwidth reserved for class 1
•
ct2—Bandwidth reserved for class 2
•
ct3—Bandwidth reserved for class 3
For example, to configure 50 megabytes of bandwidth for class type 1 and 30 megabytes
of bandwidth for class type 2, include the bandwidth statement as follows:
[edit protocols mpls]
label-switched-path traffic-class {
bandwidth {
ct1 50M;
ct2 30M;
}
}
You cannot configure a bandwidth for a class type and also configure a bandwidth at
the [edit protocols mpls label-switched-path lsp-name bandwidth] hierarchy level. For
example, the following configuration cannot be committed:
[edit protocols mpls]
label-switched-path traffic-class {
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bandwidth {
20M;
ct1 10M;
}
}
You can configure setup and holding priorities for a multiclass LSP, but the following
restrictions apply:
•
The setup and holding priorities apply to all classes for which bandwidth is requested.
•
The combination of class and priority must be one of the configured traffic engineering
classes. The default traffic engineering class configuration results in multiclass LSPs
that cannot preempt and cannot be preempted. The default setup priority is 7 and the
default holding priority is 0.
•
Configuring an invalid combination of class type and priority causes the commit
operation to fail.
•
Automatic bandwidth allocation is not supported for multiclass LSPs. If you configure
automatic bandwidth allocation, the commit operation fails.
•
LSPs configured with the bandwidth statement but without specifying a class type use
the default class type ct0.
Configuring Policing for Multiclass LSPs
Policing allows you to control the amount of traffic forwarded through a particular
multiclass LSP. Policing helps to ensure that the amount of traffic forwarded through
an LSP never exceeds the requested bandwidth allocation. You can configure multiple
policers for each multiclass LSP. You can also enable automatic policing for multiclass
LSPs.
For information about how to configure a policer for a multiclass LSP, see “Configuring
Policers for LSPs” on page 226 and “Configuring Automatic Policers” on page 228.
Configuring Fast Reroute for Multiclass LSPs
You can enable fast reroute for multiclass LSPs. The bandwidth guarantees for the class
types can be carried over to the detour path in case the primary path of the multiclass
LSP fails. The same traffic class types configured for the primary multiclass LSP are also
signaled for the detour LSP.
The bandwidth guarantee for the detour path is a percentage of the bandwidth configured
for the class types of the primary path. For example, you configure a value of 50 percent
for the detour path and the protected LSP carries traffic for class types CT0 through CT3.
The detour path is signaled with the same class types (CT0 through CT3) but with 50
percent of the bandwidth configured for the protected LSP.
If you configure the router to reserve bandwidth for the detour path, a check is made to
ensure that the link is capable of handling DiffServ-aware traffic engineering, that all of
the traffic class types needed are available, and for CoS capability before accepting it
as a potential detour path. Unsupported links are not used.
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The bandwidth percentage for fast reroute is signaled from the ingress router to the
egress router. All of the intermediate devices must complete their own CSPF computations
and signaling.
When you configure the bandwidth-percent statement, the detour path bandwidth is
computed by multiplying by the bandwidth configured for the primary multiclass LSP.
For information about how to configure the bandwidth for the multiclass LSP, see
“Configuring Traffic-Engineered LSPs” on page 186.
To configure the percentage of bandwidth used by the detour path based on the
bandwidth of the protected path, include the bandwidth-percent statement:
bandwidth-percent percentage;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name fast-reroute]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path
lsp-name fast-reroute]
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CHAPTER 7
Static and Explicit-Path LSP Configuration
Guidelines
The following sections describe how to configure static and explicit-path label-switched
paths (LSPs):
•
Configuring Static LSPs on page 193
•
Configuring Explicit-Path LSPs on page 200
Configuring Static LSPs
To configure static LSPs, configure the ingress router and each router along the path up
to and including the egress router.
To configure static MPLS, perform the following tasks:
•
Configuring the Ingress Router for Static LSPs on page 193
•
Configuring the Intermediate (Transit) and Egress Routers for Static LSPs on page 196
•
Configuring a Bypass LSP for the Static LSP on page 199
•
Configuring the Protection Revert Timer for Static LSPs on page 199
•
Configuring Static Unicast Routes for Point-to-Multipoint LSPs on page 199
Configuring the Ingress Router for Static LSPs
The ingress router checks the IP address in the incoming packet’s destination address
field and, if it finds a match in the routing table, applies the label associated with that
address to the packets. The label has forwarding information associated with it, including
the address of the next-hop router, and the route preference and CoS values.
To configure static LSPs on the ingress router, include the ingress statement:
ingress {
bandwidth bps;
class-of-service cos-value;
description string;
install {
destination-prefix <active>;
}
link-protection bypass-name name;
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metric metric;
next-hop (address | interface-name | address/interface-name);
no-install-to-address;
node-protection bypass-name name next-next-label label;
policing {
filter filter-name;
no-auto-policing;
}
preference preference;
push out-label;
to address;
}
You can include these statements at the following hierarchy levels:
•
[edit protocols mpls static-label-switched-path static-lsp-name]
•
[edit logical-systems logical-system-name protocols mpls static-label-switched-path
static-lsp-name]
When you configure a static LSP on the ingress router, the next-hop, push, and to
statements are required; the other statements are optional.
The configuration for a static LSP on the ingress router requires you to configure the
following parts:
•
Criteria for analyzing an incoming packet:
•
The install statement creates an LSP that handles IPv4 packets. All static MPLS
routes created using the install statement are installed in the default IPv4 routing
table (inet.3), and the creating protocol is identified as static. This process is no
different from creating static IPv4 routes at the [edit routing-options static] hierarchy
level.
•
In the to statement, you configure the IP destination address to check when incoming
packets are analyzed. If the address matches, the specified outgoing label (push
out-label) is assigned to the packet, and the packet enters an LSP. Manually assigned
outgoing labels can have values from 0 through 1,048,575. Each prefix that you
specify is installed as a static route in the routing table.
•
The next-hop statement, which supplies the IP address of the next hop to the
destination. You can specify this as the IP address of the next hop, the interface name
(for point-to-point interfaces only), or as address/interface-name to specify an IP
address on an operational interface. When the next hop is on a directly attached
interface, the route is installed in the routing table. You cannot configure a LAN or
nonbroadcast multiaccess (NBMA) interface as a next-hop interface.
•
Properties to apply to the LSP (all are optional):
•
Bandwidth reserved for this LSP (bandwidth bps)
•
Link protection and node protection to apply to the LSP (bypass bypass-name,
link-protection bypass-name name, node-protection bypass-name next-next-label
label)
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•
Metric value to apply to the LSP (metric)
•
Class-of-service value to apply to the LSP (class-of-service)
•
Preference value to apply to the LSP (preference)
•
Traffic policing to apply to the LSP (policing)
•
Text description to apply to the LSP (description)
•
Install or no-install policy (install or no-install-to-address)
To determine whether a static ingress route is installed, use the command show route
table inet.0 protocol static. Sample output follows. The push keyword denotes that a
label is to be added in front of an IP packet.
10.0.0.0
*[Static/5] 00:01:48
> to 11.1.1.1 via so-0/0/0, push 1000123
Example: Configuring the Ingress Router
Configure the ingress router for a static LSP that consists of three routers (see Figure 21
on page 195).
Figure 21: Static MPLS Configuration
For packets addressed to 10.0.0.0, assign label 1000123 and transmit them to the next-hop
router at 11.1.1.1:
[edit]
interfaces {
so-0/0/0 {
unit 0 {
family mpls;
}
}
}
protocols {
mpls {
static-label-switched-path path1 {
ingress {
next-hop 11.1.1.1;
to 10.0.0.0;
push 1000123;
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}
}
interface so-0/0/0.0;
}
}
routing-options {
static {
route 10.0.0.0/8 {
static-lsp-next-hop path1;
}
}
To determine whether the static ingress route is installed, use the following command:
user@host> show route table inet.0 protocol static
Sample output follows. The push 1000123 keyword identifies the route.
10.0.0.0/8
*[Static/5] 00:01:48
> to 11.1.1.1 via so-0/0/0.0, push 1000123
Configuring the Intermediate (Transit) and Egress Routers for Static LSPs
Intermediate (transit) and egress routers perform similar functions—they modify the
label that has been applied to a packet. An intermediate router can change the label. An
egress router removes the label (if the packet still contains a label) and continues
forwarding the packet to its destination.
To configure static LSPs on intermediate and egress routers, include the transit statement:
static-label-switched-path lsp-name {
transit incoming-label {
bandwidth bps;
description string;
link-protection bypass-name name;
next-hop (address | interface-name | address/interface-name);
node-protection bypass-name name next-next-label label;
pop;
swap out-label;
}
You can include these statements at the following hierarchy levels:
•
[edit protocols mpls static-label-switched-path static-lsp-name]
•
[edit logical-systems logical-system-name protocols mpls static-label-switched-path
static-lsp-name]
For the transit statement configuration, the next-hop and pop | swap statements are
required. The remaining statements are optional.
Each statement within the transit statement consists of the following parts:
196
•
Packet label (specified in the transit statement)
•
The next-hop statement, which supplies the IP address of the next hop to the
destination. The address is specified as the IP address of the next hop, or the interface
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name (for point-to-point interfaces only), or address and interface-name to specify an
IP address on an operational interface. When the specified next hop is on a directly
attached interface, this route is installed in the routing table. You cannot configure a
LAN or NBMA interface as a next-hop interface.
•
•
Operation to perform on the labeled packet:
•
For egress routers, you generally just remove the packet’s label altogether (pop) and
continue forwarding the packet to the next hop. However, if the previous router
removed the label, the egress router examines the packet’s IP header and forwards
the packet toward its IP destination.
•
For intermediate (transit) routers only, exchange the label for another label (swap
out-label). Manually assigned incoming labels can have values from 1,000,000
through 1,048,575. Manually assigned outgoing labels can have values from 0 through
1,048,575.
Label properties to apply to the packet (all are optional):
•
Bandwidth reserved for this route (bandwidth bps).
•
Link-protection and node-protection to apply to the LSP (bypass bypass-name,
link-protection bypass-name name, node-protection bypass-name next-next-label
label).
•
Text description to apply to the LSP (specified in the description statement).
The static routes are installed in the default MPLS routing table, mpls.0, and the creating
protocol is identified as static. To verify that a static route is properly installed, use the
command show route table mpls.0 protocol static. Sample output follows:
1000123
*[Static/5] 00:00:38
> to 12.2.2.2 via so-5/0/0.0, swap 1000456
You can configure a revert timer for a static LSP transiting an intermediate router. After
traffic has been switched to a bypass static LSP, it is typically switched back to the
primary static LSP when it comes back up. There is a configurable delay in the time (called
the revert timer) between when the primary static LSP comes up and when traffic is
reverted back to it from the bypass static LSP. This delay is needed because when the
primary LSP comes back up, it is not certain whether all of the interfaces on the
downstream node of the primary path have come up yet. You can display the revert timer
value for an interface using the show mpls interface detail command. For more information,
see “Configuring the Revert Timer for LSPs” on page 132.
Example: Configuring an Intermediate Router
For packets labeled 1000123 arriving on interface so-0/0/0, assign the label 1000456,
and transmit them to the next-hop router at 12.2.2.2:
[edit]
interfaces {
so-0/0/0 {
unit 0 {
family mpls;
}
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}
}
protocols {
mpls {
static-label-switched-path path1 {
transit 1000123 {
next-hop 12.2.2.2;
swap 1000456;
}
}
interface so-0/0/0.0;
}
}
To determine whether the static intermediate route is installed, use the following
command:
user@host> show route table mpls.0 protocol static
Sample output follows. The swap 1000456 keyword identifies the route.
1000123
*[Static/5] 00:01:48
> to 12.2.2.2 via so-0/0/0, swap 1000456
Example: Configuring an Egress Router
For packets labeled 1000456 arriving on interface so-0/0/0, remove the label and transmit
the packets to the next-hop router at 13.3.3.3:
[edit]
interfaces {
so-0/0/0 {
unit 0 {
family mpls;
}
}
}
protocols {
mpls {
static-label-switched-path path1 {
transit 1000456 {
next-hop 13.3.3.3;
pop;
}
}
interface so-0/0/0.0;
}
}
To determine whether the static egress route is installed, use the following command:
user@host> show route table mpls.0 protocol static
Sample output follows. The pop keyword identifies the egress route.
1000456
*[Static/5] 00:01:48
> to 13.3.3.3 via so-0/0/0, pop
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Configuring a Bypass LSP for the Static LSP
To enable a bypass LSP for the static LSP, configure the bypass statement:
bypass bypass-name {
bandwidth bps;
description string;
next-hop (address | interface-name | address/interface-name);
push out-label;
to address;
}
Configuring the Protection Revert Timer for Static LSPs
For static LSPs configured with a bypass static LSP, it is possible to configure the
protection revert timer. If a static LSP goes down and traffic is switched to the bypass
LSP, the protection revert timer specifies the amount of time (in seconds) that the LSP
must wait before it can revert back to the original static LSP.
The range of values you can configure for the protection revert timer is 0 through 65,535
seconds. The default value is 5 seconds.
If you configure a value of 0 seconds, the traffic on the LSP, once switched from the
original static LSP to the bypass static LSP, remains on the bypass LSP permanently
(until the network operator intervenes or until the bypass LSP goes down).
You can configure the protection revert timer for all LSPs on the router at the [edit
protocols mpls] hierarchy level or for a specific LSP at the [edit protocols mpls
label-switched-path lsp-name] hierarchy level.
To configure the protection revert timer for static LSPs include the protection-revert-time
statement:
protection-revert-time seconds;
For a list of hierarchy levels at which you can include this statement, see the summary
section for this statement.
Configuring Static Unicast Routes for Point-to-Multipoint LSPs
You can configure a static unicast IP route with a point-to-multipoint LSP as the next
hop. For more information about point-to-multipoint LSPs, see “Point-to-Multipoint LSPs
Overview” on page 52, “Configuring Primary and Branch LSPs for Point-to-Multipoint
LSPs” on page 203, and “Configuring CCC Switching for Point-to-Multipoint LSPs” on
page 524.
To configure a static unicast route for a point-to-multipoint LSP, complete the following
steps:
1.
On the ingress PE router, configure a static IP unicast route with the point-to-multipoint
LSP name as the next hop by including the p2mp-lsp-next-hop statement:
p2mp-lsp-next-hop point-to-multipoint-lsp-next-hop;
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You can include this statement at the following hierarchy levels:
•
[edit routing-options static route route-name]
•
[edit logical-systems logical-system-name routing-options static route route-name]
2. On the egress PE router, configure a static IP unicast route with the same destination
address configured in Step 1 (the address configured at the [edit routing-options static
route] hierarchy level) by including the next-hop statement:
next-hop address;
You can include this statement at the following hierarchy levels:
•
[edit routing-options static route route-name]
•
[edit logical-systems logical-system-name routing-options static route route-name]
NOTE: CCC and static routes cannot use the same point-to-multipoint
LSP.
For more information on static routes, see the Junos OS Routing Protocols Configuration
Guide.
The following show route command output displays a unicast static route pointing to a
point-to-multipoint LSP on the ingress PE router where the LSP has two branch next
hops:
user@host> show route 5.5.5.5 detail
inet.0: 29 destinations, 30 routes (28 active, 0 holddown, 1 hidden)
5.5.5.5/32 (1 entry, 1 announced)
*Static Preference: 5
Next hop type: Flood
Next hop: via so-0/3/2.0 weight 1
Label operation: Push 100000
Next hop: via t1-0/1/1.0 weight 1
Label operation: Push 100064
State: <Active Int Ext>
Local AS: 10458
Age: 2:41:15
Task: RT
Announcement bits (2): 0-KRT 3-BGP.0.0.0.0+179
AS path: I
Configuring Explicit-Path LSPs
If you disable constrained-path label-switched path (LSP) computation, as described
in “Disabling Constrained-Path LSP Computation” on page 152, you can configure LSPs
manually or allow the LSPs to follow the IGP path.
When explicit-path LSPs are configured, the LSP is established along the path you
specified. If the path is topologically not feasible, either because the network is partitioned
or insufficient resources are available along some parts of the path, the LSP will fail. No
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alternative paths can be used. If the setup succeeds, the LSP stays on the defined path
indefinitely.
To configure an explicit-path LSP, follow these steps:
1.
Configure the path information in a named path, as described in “Creating Named
Paths” on page 56. To configure complete path information, specify every router hop
between the ingress and egress routers, preferably using the strict attribute. To
configure incomplete path information, specify only a subset of router hops, using the
loose attribute in places where the path is incomplete.
For incomplete paths, the MPLS routers complete the path by querying the local
routing table. This query is done on a hop-by-hop basis, and each router can figure
out only enough information to reach the next explicit hop. It might be necessary to
traverse a number of routers to reach the next (loose) explicit hop.
Configuring incomplete path information creates portions of the path that depend
on the current routing table, and this portion of the path can reroute itself as the
topology changes. Therefore, an explicit-path LSP that contains incomplete path
information is not completely fixed. These types of LSPs have only a limited ability to
repair themselves, and they tend to create loops or flaps depending on the contents
of the local routing table.
2. To configure the LSP and point it to the named path, use either the primary or secondary
statement, as described in “Configuring Primary and Secondary LSPs” on page 131.
3. Disable constrained-path LSP computation by including the no-cspf statement either
as part of the LSP or as part of a primary or secondary statement. For more information,
see “Disabling Constrained-Path LSP Computation” on page 152.
4. Configure any other LSP properties.
Using explicit-path LSPs has the following drawbacks:
•
More configuration effort is required.
•
Configured path information cannot take into account dynamic network bandwidth
reservation, so the LSPs tend to fail when resources become depleted.
•
When an explicit-path LSP fails, you might need to manually repair it.
Because of these limitations, we recommend that you use explicit-path LSPs only in
controlled situations, such as to enforce an optimized LSP placement strategy resulting
from computations with an offline simulation software package.
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CHAPTER 8
Point-to-Multipoint LSP Configuration
Guidelines
This chapter discusses the following topics:
•
Configuring Primary and Branch LSPs for Point-to-Multipoint LSPs on page 203
•
Configuring Link Protection for Point-to-Multipoint LSPs on page 205
•
Configuring Graceful Restart for Point-to-Multipoint LSPs on page 206
•
Configuring a Multicast RPF Check Policy for Point-to-Multipoint LSPs on page 206
•
Configuring Ingress PE Router Redundancy for Point-to-Multipoint LSPs on page 207
•
Enabling Point-to-Point LSPs to Monitor Egress PE Routers on page 208
•
Preserving Point-to-Multipoint LSP Functioning with Different Junos OS
Releases on page 209
•
Example: Configuring a Point-to-Multipoint LSP on page 209
•
Configuring Inter-domain P2MP LSPs on page 209
Configuring Primary and Branch LSPs for Point-to-Multipoint LSPs
A point-to-multipoint MPLS label-switched path (LSP) is an RSVP LSP with multiple
destinations. By taking advantage of the MPLS packet replication capability of the network,
point-to-multipoint LSPs avoid unnecessary packet replication at the ingress router. For
more information about point-to-multipoint LSPs, see “Point-to-Multipoint LSPs
Overview” on page 52.
To configure a point-to-multipoint LSP, you need to configure the primary LSP from the
ingress router and the branch LSPs that carry traffic to the egress routers, as described
in the following sections:
•
Configuring the Primary Point-to-Multipoint LSP on page 204
•
Configuring a Branch LSP for Point-to-Multipoint LSPs on page 204
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Configuring the Primary Point-to-Multipoint LSP
A point-to-multipoint LSP must have a configured primary point-to-multipoint LSP to
carry traffic from the ingress router. The configuration of the primary point-to-multipoint
LSP is similar to a signaled LSP. See “Configuring the Ingress Router for MPLS-Signaled
LSPs” on page 56 for more information. In addition to the conventional LSP configuration,
you need to specify a path name for the primary point-to-multipoint LSP by including
the p2mp statement:
p2mp p2mp-lsp-name;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name]
You can enable the optimization timer for point-to-multipoint LSPs. See “Optimizing
Signaled LSPs” on page 161 for more information.
Configuring a Branch LSP for Point-to-Multipoint LSPs
The primary point-to-multipoint LSP sends traffic to two or more branch LSPs carrying
traffic to each of the egress provider edge (PE) routers. In the configuration for each of
these branch LSPs, the point-to-multipoint LSP path name you specify must be identical
to the path name configured for the primary point-to-multipoint LSP. See “Configuring
the Primary Point-to-Multipoint LSP” on page 204 for more information.
To associate a branch LSP with the primary point-to-multipoint LSP, specify the
point-to-multipoint LSP name by including the p2mp statement:
p2mp p2mp-lsp-name;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name]
NOTE: Any change in any of the branch LSPs of a point-to-multipoint LSP,
either due to a user action or an automatic adjustment made by the router,
causes the primary and branch LSPs to be resignaled. The new
point-to-multipoint LSP is signaled first before the old path is taken down.
The following sections describe how you can configure the branch LSP as a dynamically
signaled path using Constrained Shortest Path First (CSPF), as a static path, or as a
combination of dynamic and static paths:
204
•
Configuring the Branch LSP as a Dynamic Path on page 205
•
Configuring the Branch LSP as a Static Path on page 205
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Chapter 8: Point-to-Multipoint LSP Configuration Guidelines
Configuring the Branch LSP as a Dynamic Path
By default, the branch LSP for a point-to-multipoint LSP is signaled dynamically using
CSPF and requires no configuration.
When a point-to-multipoint LSP is changed, either by the addition or deletion of new
destinations or by the recalculation of the path to existing destinations, certain nodes in
the tree might receive data from more than one incoming interface. This can happen
under the following conditions:
•
Some of the branch LSPs to destinations are statically configured and might intersect
with statically or dynamically calculated paths to other destinations.
•
When a dynamically calculated path for a branch LSP results in a change of incoming
interface for one of the nodes in the network, the older path is not immediately torn
down after the new one has been signaled. This ensures that any data in transit relying
on the older path can reach its destination. However, network traffic can potentially
use either path to reach the destination.
•
A faulty router at the ingress calculates the paths to two different branch destinations
such that a different incoming interface is chosen for these branch LSPs on a router
node common to these branch LSPs.
Configuring the Branch LSP as a Static Path
You can configure the branch LSP for a point-to-multipoint LSP as a static path. See
“Configuring Static LSPs” on page 193 for more information.
Configuring Link Protection for Point-to-Multipoint LSPs
Link protection helps to ensure that traffic going over a specific interface to a neighboring
router can continue to reach this router if that interface fails. When link protection is
configured for an interface and a point-to-multipoint LSP that traverses this interface,
a bypass LSP is created that handles this traffic if the interface fails. The bypass LSP
uses a different interface and path to reach the same destination.
To extend link protection to all of the paths used by a point-to-multipoint LSP, link
protection must be configured on each router that each branch LSP traverses. If you
enable link protection on a point-to-multipoint LSP, you must enable link protection on
all of the branch LSPs.
The Internet draft draft-ietf-mpls-rsvp-te-p2mp-01.txt, Extensions to RSVP-TE for Point
to Multipoint TE LSPs, describes link protection for point-to-multipoint LSPs.
To enable link protection on point-to-multipoint LSPs, complete the following steps:
1.
Configure link protection on each branch LSP. To configure link protection, include
the link-protection statement:
link-protection;
You can include this statement at the following hierarchy levels:
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•
[edit protocols mpls label-switched-path branch-lsp-name]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path
branch-lsp-name]
2. Configure link protection for each RSVP interface on each router that the branch LSP
traverses. For information about how to configure link protection on RSVP interfaces,
see “Configuring Link Protection on Interfaces Used by LSPs” on page 366.
For more information on how to configure link protection, see “Configuring Node Protection
or Link Protection for LSPs” on page 364.
Configuring Graceful Restart for Point-to-Multipoint LSPs
You can configure graceful restart on point-to-multipoint LSPs. Graceful restart allows
a router undergoing a restart to inform its adjacent neighbors of its condition. The
restarting router requests a grace period from the neighbor or peer, which can then
cooperate with the restarting router. The restarting router can still forward MPLS traffic
during the restart period; convergence in the network is not disrupted. The restart is not
apparent to the rest of the network, and the restarting router is not removed from the
network topology. RSVP graceful restart can be enabled on both transit routers and
ingress routers.
To enable graceful restart on a router handling point-to-multipoint LSP traffic, include
the graceful-restart statement:
graceful-restart;
You can include this statement at the following hierarchy levels:
•
[edit routing-options]
•
[edit logical-systems logical-system-name routing-options]
The graceful restart configuration for point-to-multipoint LSPs is identical to that of
point-to-point LSPs. For more information on how to configure graceful restart, see
“Configuring RSVP Graceful Restart” on page 374.
Configuring a Multicast RPF Check Policy for Point-to-Multipoint LSPs
You can control whether a reverse path forwarding (RPF) check is performed for a source
and group entry before installing a route in the multicast forwarding cache. This makes
it possible to use point-to-multipoint LSPs to distribute multicast traffic to PIM islands
situated downstream from the egress routers of the point-to-multipoint LSPs.
By configuring the rpf-check-policy statement, you can disable RPF checks for a source
and group pair. You would typically configure this statement on the egress routers of a
point-to-multipoint LSP, because the interface receiving the multicast traffic on a
point-to-multipoint LSP egress router might not always be the RPF interface.
You can also configure a routing policy to act upon a source and group pair. This policy
behaves like an import policy, so if no policy term matches the input data, the default
policy action is “acceptance.” An accept policy action enables RPF checks. A reject policy
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action (applied to all source and group pairs that are not accepted) disables RPF checks
for the pair.
To configure a multicast RPF check policy for a point-to-multipoint LSP, specify the RPF
check policy using the rpf-check-policy statement:
rpf-check-policy policy;
You can include this statement at the following hierarchy levels:
•
[edit routing-options multicast]
•
[edit logical-systems logical-system-name routing-options multicast]
You also must configure a policy for the multicast RPF check. You configure policies at
the [edit policy-options] hierarchy level. For more information, see the Junos OS Routing
Policy Configuration Guide.
NOTE: When you configure the rpf-check-policy statement, the Junos OS
cannot perform RPF checks on incoming traffic and therefore cannot detect
traffic arriving on the wrong interface. This might cause routing loops to form.
Example: Configuring Multicast RPF Check Policy for a Point-to-Multipoint LSP
Configure a policy to ensure that an RPF check is not performed for sources with prefix
128.83/16 or longer that belong to groups having a prefix of 228/8 or longer:
[edit]
policy-options {
policy-statement rpf-sg-policy {
from {
route-filter 228.0.0.0/8 orlonger;
source-address-filter 128.83.0.0/16 orlonger;
}
then {
reject;
}
}
}
Configuring Ingress PE Router Redundancy for Point-to-Multipoint LSPs
You can configure one or more PE routers as part of a backup PE router group to enable
ingress PE router redundancy. You accomplish this by configuring the IP addresses of
the backup PE routers (at least one backup PE router is required) and the local IP address
used by the local PE router.
You must also configure a full mesh of point-to-point LSPs between the primary and
backup PE routers. You also need to configure BFD on these LSPs. See “Configuring BFD
for RSVP-Signaled LSPs” on page 234 and “Configuring BFD for LDP LSPs” on page 448 for
more information.
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To configure ingress PE router redundancy for point-to-multipoint LSPs, include the
backup-pe-group statement:
backup-pe-group pe-group-name {
backups [addresses];
local-address address;
}
For a list of hierarchy levels at which you can include these statements, see the statement
summary sections for these statements.
After you configure the ingress PE router redundancy backup group, you must also apply
the group to a static route on the PE router. This ensures that the static route is active
(installed in the forwarding table) when the local PE router is the designated forwarder
for the backup PE group. You can only associate a backup PE router group with a static
route that also has the p2mp-lsp-next-hop statement configured. For more information,
see “Configuring Static Unicast Routes for Point-to-Multipoint LSPs” on page 199.
Enabling Point-to-Point LSPs to Monitor Egress PE Routers
Configuring an LSP with the associate-backup-pe-groups statement enables it to monitor
the status of the PE router to which it is configured. You can configure multiple backup
PE router groups using the same router's address. A failure of this LSP indicates to all of
the backup PE router groups that the destination PE router is down. The
associate-backup-pe-groups statement is not tied to a specific backup PE router group.
It applies to all groups that are interested in the status of the LSP to that address.
To allow an LSP to monitor the status of the egress PE router, include the
associate-backup-pe-groups statement:
associate-backup-pe-groups;
This statement can be configured at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name]
If you configure the associate-backup-pe-groups statement, you must configure BFD for
the point-to-point LSP. For information about how to configure BFD for an LSP, see
“Configuring BFD for MPLS IPv4 LSPs” on page 233 and “Configuring BFD for LDP LSPs”
on page 448.
You also must configure a full mesh of point-to-point LSPs between the PE routers in
the backup PE router group. A full mesh is required so that each PE router within the
group can independently determine the status of the other PE routers, allowing each
router to independently determine which PE router is currently the designated forwarder
for the backup PE router group.
If you configure multiple LSPs with the associate-backup-pe-groups statement to the
same destination PE router, the first LSP configured is used to monitor the forwarding
state to that PE router. If you configure multiple LSPs to the same destination, make sure
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to configure similar parameters for the LSPs. With this configuration scenario, a failure
notification might be triggered even though the remote PE router is still up.
Preserving Point-to-Multipoint LSP Functioning with Different Junos OS Releases
In Junos OS Release 9.1 and earlier, Resv messages that include the S2L_SUB_LSP object
are rejected by default. In Junos OS Release 9.2 and later, such messages are accepted
by default. To ensure proper functioning of point-to-multipoint LSPs in a network that
includes both devices running Junos OS Release 9.1 and earlier and devices running Junos
9.2 and later, you must include the no-p2mp-sublsp statement in the configuration of
the devices running Junos 9.2 and later:
no-p2mp-sublsp;
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp]
•
[edit logical-systems logical-system-name protocols rsvp]
Example: Configuring a Point-to-Multipoint LSP
Configure a point-to-multipoint LSP based on the topology shown in Figure 18 on page 52.
There are four branch LSPs, each belonging to a single point-to-multipoint LSP called
p2mp-lsp-sample.
[edit protocols mpls]
label-switched-path branch-LSP-to-PE2 {
to 10.255.235.25;
p2mp p2mp-lsp-sample;
primary path1;
}
label-switched-path branch-LSP-to-PE2 {
to 10.255.235.25;
p2mp p2mp-lsp-sample;
primary path2;
}
label-switched-path branch-LSP-to-PE3 {
to 10.255.241.34;
p2mp p2mp-lsp-sample;
primary path3;
}
label-switched-path branch-LSP-to-CE4 {
to 10.255.244.125;
p2mp p2mp-lsp-sample;
primary path4;
}
Configuring Inter-domain P2MP LSPs
An inter-domain P2MP LSP is a P2MP LSP that has one or more sub-LSPs (branches)
that span multiple domains in a network. Examples of such domains include IGP areas
and autonomous systems (ASs). A sub-LSP of an inter-domain P2MP LSP may be
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intra-area, inter-area, or inter-AS, depending on the location of the egress node (leaf)
with respect to the ingress node (source).
On the ingress node, a name is assigned to the inter-domain P2MP LSP and shared by
all constituent sub-LSPs. Each sub-LSP is configured separately, with its own egress
node and optionally an explicit path. The location of the egress node of the sub-LSP with
respect to the ingress node determines whether the sub-LSP is intra-area, inter-area, or
inter-AS.
Inter-domain P2MP LSPs can be used to transport traffic in the following applications
in a multi-area or multi-AS network:
•
Layer 2 broadcast and multicast over MPLS
•
Layer 3 BGP/MPLS VPN
•
VPLS
On each domain boundary node (ABR or ASBR) along the path of the P2MP LSP, the
expand-loose-hop statement must be configured at the [edit protocols mpls] hierarchy
level so that CSPF can extend a loose-hop ERO (usually the first entry of the ERO list
carried by RSVP Path message) towards the egress node or the next domain boundary
node.
CSPF path computation for inter-domain P2MP LSPs:
•
CSPF path computation is supported on each sub-LSP for inter-domain P2MP LSPs.
A sub-LSP may be intra-area, inter-area, or inter-AS. CSPF treats an inter-area or
inter-AS sub-LSP in the same manner as an inter-domain P2P LSP.
•
On an ingress node or a domain boundary node (ABR or ASBR), CSPF can perform an
Explicit Route Object (ERO) expansion per-RSVP query. The destination queried could
be an egress node or a received loose-hop ERO. If the destination resides in a
neighboring domain that the node is connected to, CSPF generates either a sequence
of strict-hop EROs towards it or a sequence of strict-hop EROs towards another domain
boundary node that can reach the destination.
•
If RSVP fails to signal a path through a previously selected domain bounday node,
RSVP attempts to signal a path through other available domain boundary nodes in a
round-robin fashion.
•
When a sub-LSP is added or removed to or from an inter-domain P2MP LSP, causing
its path (branch) to be merged or pruned with or from the current P2MP tree, the paths
being taken by the other sub-LSPs should not be affected, helping to prevent traffic
disruption on those sub-LSPs.
Be aware of the following when deploying inter-domain P2MP LSPs in your network:
•
210
Periodic path re-optimization is supported for inter-domain P2MP LSPs on ingress
nodes. It can be turned on for an inter-domain P2MP LSP by configuring the
optimize-timer statement at the [edit protocols mpls label-switched-path lsp-name]
hierarchy level with the same interval for every sub-LSP.
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Chapter 8: Point-to-Multipoint LSP Configuration Guidelines
•
Only link protection bypass LSPs are supported for inter-domain P2MP LSPs. To enable
it for an inter-domain P2MP LSP, link-protection must be configured for all sub-LSPs
and on all of the RSVP interfaces that the P2MP LSP might travel through.
•
Only OSPF areas are supported for inter-domain P2MP LSPs. IS-IS levels are not
supported.
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CHAPTER 9
Miscellaneous MPLS Properties
Configuration Guidelines
This chapter discusses the following topics:
•
Configuring the Maximum Number of MPLS Labels on page 213
•
Configuring MPLS to Pop the Label on the Ultimate-Hop Router on page 215
•
Advertising Explicit Null Labels to BGP Peers on page 215
•
Configuring Traffic Engineering for LSPs on page 216
•
Enabling Interarea Traffic Engineering on page 219
•
Enabling Inter-AS Traffic Engineering for LSPs on page 219
•
Configuring MPLS to Gather Statistics on page 222
•
Configuring System Log Messages and SNMP Traps for LSPs on page 223
•
Configuring MPLS Firewall Filters and Policers on page 224
•
Configuring MPLS Rewrite Rules on page 232
•
Configuring BFD for MPLS IPv4 LSPs on page 233
•
Pinging LSPs on page 236
•
Tracing MPLS and LSP Packets and Operations on page 237
Configuring the Maximum Number of MPLS Labels
For interfaces that you configure for MPLS applications, you can set the maximum number
of labels upon which MPLS can operate.
By default, the maximum number of labels is three. You can change the maximum to
four labels or five labels for applications that require four or five labels. For example,
suppose you configure a two-tier carrier-of-carriers VPN service for customers who
provide VPN service. A carrier-of-carrier VPN is a two-tiered relationship between a
provider carrier (Tier 1 ISP) and a customer carrier (Tier 2 ISP). In a carrier-of-carrier VPN,
the provider carrier provides a VPN backbone network for the customer carrier. The
customer carrier in turn provides Layer 3 VPN service to its end customers. The customer
carrier sends labeled traffic to the provider carrier to deliver it to the next hop on the other
side of the provider carrier’s network. This scenario requires a three-label stack: one label
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for the provider carrier VPN, another label for the customer carrier VPN, and a third label
for the transport route.
If you add fast reroute service, the PE routers in the provider carrier’s network must be
configured to support a fourth label (the reroute label). If the customer carrier is using
LDP as its signaling protocol and the provider carrier is using RSVP, the provider carrier
must support LDP over RSVP tunnel service. This additional service requires an additional
label, for a total of five labels.
To the customer carrier, the router it uses to connect to the provider carrier’s VPN is a PE
router. However, the provider carrier views this device as a CE router.
Table 6 on page 214 summarizes the label requirements.
Table 6: Sample Scenarios for Using 3, 4, or 5 MPLS Labels
Number of Labels Required
Scenarios
3
Carrier-of-carriers VPN or a VPN with two labels and fast reroute
4
Combination of carrier-of-carriers and fast reroute
5
Carrier-of-carriers with fast reroute and the customer carrier running LDP, with
the provider carrier running RSVP
The system reserves label space when you configure the maximum number of labels on
the interface. When you configure features that require MPLS labels, the label push is
automatic. You do not need to explicitly push the labels. The transport route can be a
static, LDP-signaled, or RSVP-signaled LSP.
To configure and monitor the maximum number of labels:
1.
Specify the maximum on the logical interface. Apply this configuration to the carrier’s
PE routers.
[edit interfaces ge-0/1/3 unit 0 family mpls]
user@switch# set maximum-labels 5
2. Verify the configuration.
[edit system]
user@switch# show interfaces ge-0/1/3.0
Logical interface ge-0/1/3.0 (Index 77) (SNMP ifIndex 507)
Flags: SNMP-Traps Encapsulation: ENET2
Input packets : 0
Output packets: 0
Protocol mpls, MTU: 1480, Maximum labels: 5
Flags: Is-Primary
The command output includes the Maximum labels: 5 field under the logical interface
unit 0.
Related
Documentation
214
•
Fast Reroute Overview on page 47
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Chapter 9: Miscellaneous MPLS Properties Configuration Guidelines
•
Tunneling LDP LSPs in RSVP LSPs Overview on page 427
•
Junos VPNs Configuration Guide for a carrier-of-carriers configuration example
Configuring MPLS to Pop the Label on the Ultimate-Hop Router
You can control the label value advertised on the egress router of a label-switched path
(LSP). The default advertised label is label 3 (Implicit Null Label). If label 3 is advertised,
the penultimate-hop router removes the label and sends the packet to the egress router.
By enabling ultimate-hop popping, label 0 (IPv4 Explicit Null Label) is advertised.
Ultimate-hop popping ensures that any packets traversing an MPLS network include a
label.
To configure MPLS to pop the label on the ultimate-hop router, include the explicit-null
statement:
explicit-null;
You can configure this statement at the following hierarchy levels:
•
[edit protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls]
NOTE: Juniper Networks routers queue packets based on the incoming
label. Routers from other vendors might queue packets differently. Keep
this in mind when working with networks containing routers from multiple
vendors.
For more information about labels, see “Label Description” on page 27 and “Label
Allocation” on page 28.
Advertising Explicit Null Labels to BGP Peers
For the IPv4 (inet) family only, BGP peers in a routing group can send an explicit NULL
label for a set of connected routes (direct and loopback routes) for the inet
labeled-unicast and inet6 labeled-unicast NLRI. By default, peers advertise label 3
(implicit NULL). If the explicit-null statement is enabled, peers advertise label 0 (explicit
NULL). The explicit NULL labels ensures that labels are always present on packets
traversing an MPLS network. If the implicit NULL label is used. the penultimate hop router
removes the label and sends the packet as a plain IP packet to the egress router. This
might cause issues in queuing the packet properly on the penultimate hop router if the
penultimate hop is another vendor’s router. Some other vendors queue packets based
on the CoS bits in the outgoing label rather than the incoming label.
To advertise an explicit null label, include the following statements in the configuration:
family inet {
labeled-unicast {
aggregate-label {
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community community-name:
}
explicit-null {
connected-only;
}
}
}
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
The connected-only statement is required to advertise explicit null labels.
To verify that the explicit NULL label is being advertised for connected routes, use the
show route advertising-protocol bgp neighbor-address command.
Related
Documentation
•
Configuring MPLS and LDP to Pop the Label on the Ultimate-Hop Router on page 458
•
Configuring RSVP to Pop the Label on the Ultimate-Hop Router on page 381
Configuring Traffic Engineering for LSPs
When you configure an LSP, a host route (a 32-bit mask) is installed in the ingress router
toward the egress router; the address of the host route is the destination address of the
LSP. The bgp option for the traffic engineering statement at the [edit protocols mpls]
hierarchy level is enabled by default (you can also explicitly configure the bgp option),
allowing only BGP to use LSPs in its route calculations. The other traffic-engineering
statement options allow you to alter this behavior in the master routing instance. This
functionality is not available for specific routing instances. Also, you can enable only one
of the traffic-engineering statement options (bgp, bgp-igp, bgp-igp-both-ribs, or
mpls-forwarding) at a time.
NOTE: Enabling or disabling any of the traffic-engineering statement options
causes all the MPLS routes to be removed and then reinserted into the routing
tables.
You can configure OSPF and traffic engineering to advertise the LSP metric in summary
link-state advertisements (LSAs) as described in the section “Advertising the LSP Metric
in Summary LSAs” on page 218.
The following sections describe how to configure traffic engineering for LSPs:
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•
Using LSPs for Both BGP and IGP Traffic Forwarding on page 217
•
Using LSPs for Forwarding in Virtual Private Networks on page 217
•
Using RSVP and LDP Routes for Forwarding but Not Route Selection on page 217
•
Advertising the LSP Metric in Summary LSAs on page 218
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Using LSPs for Both BGP and IGP Traffic Forwarding
You can configure BGP and the IGPs to use LSPs for forwarding traffic destined for egress
routers by including the bgp-igp option for the traffic-engineering statement. The bgp-igp
option causes all inet.3 routes to be moved to the inet.0 routing table.
On the ingress router, include bgp-igp option for the traffic-engineering statement:
traffic-engineering bgp-igp;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls]
NOTE: The bgp-igp option for the traffic-engineering statement cannot be
configured for VPN). VPNs require that routes be in the inet.3 routing table.
Using LSPs for Forwarding in Virtual Private Networks
VPNs require that routes remain in the inet.3 routing table to function properly. For VPNs,
configure the bgp-igp-both-ribs option of the traffic-engineering statement to cause BGP
and the IGPs to use LSPs for forwarding traffic destined for egress routers. The
bgp-igp-both-ribs option installs the ingress routes in both the inet.0 routing table (for
IPv4 unicast routes) and the inet.3 routing table (for MPLS path information).
On the ingress router, include the traffic-engineering bgp-igp-both-ribs statement:
traffic-engineering bgp-igp-both-ribs;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls]
When you use the bgp-igp-both-ribs statement, the routes from the inet.3 table get copied
into the inet.0 table. The copied routes are LDP-signaled or RSVP-signaled, and are likely
to have a lower preference than other routes in inet.0. Routes with a lower preference
are more likely to be chosen as the active routes. This can be a problem because routing
policies only act upon active routes. To prevent this problem, use the mpls-forwarding
option instead.
Using RSVP and LDP Routes for Forwarding but Not Route Selection
If you configure the bgp-igp or bgpp-igp-both-ribs options for the traffic-engineering
statement, high-priority LSPs can supersede IGP routes in the inet.0 routing table. IGP
routes might no longer be redistributed since they are no longer the active routes.
If you configure the mpls-forwarding option for the traffic-engineering statement, LSPs
are used for forwarding but are excluded from route selection. These routes are added
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to both the inet.0 and inet.3 routing tables. LSPs in the inet.0 routing table are given a
low preference when the active route is selected. However, LSPs in the inet.3 routing
table are given a normal preference and are therefore used for selecting forwarding next
hops.
When you activate the mpls-forwarding option, routes whose state is ForwardingOnly
are preferred for forwarding even if their preference is lower than that of the currently
active route. To examine the state of a route, execute a show route detail command.
To use LSPs for forwarding but exclude them from route selection, include the
mpls-forwarding option for the traffic-engineering statement:
traffic-engineering mpls-forwarding;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls]
When you configure the mpls-forwarding option, IGP shortcut routes are copied to the
inet.0 routing table only.
Unlike the bgp-igp-both-ribs option, the mpls-forwarding option allows you to use the
LDP-signaled and RSVP-signaled routes for forwarding, and keep the BGP and IGP routes
active for routing purposes so that routing policies can act upon them.
For example, suppose a router is running BGP and it has a BGP route of 10.10.10.1/32 that
it needs to send to another BGP speaker. If you use the bgp-igp-both-ribs option, and
your router also has a label-switched-path (LSP) to 10.10.10.1, the MPLS route for 10.10.10.1
becomes active in the inet.0 routing table. This prevents your router from advertising the
10.10.10.1 route to the other BGP router. On the other hand, if you use the mpls-forwarding
option instead of the bgp-igp-both-ribs option, the 10.10.10.1/32 BGP route is advertised
to the other BGP speaker, and the LSP is still used to forward traffic to the 10.10.10.1
destination.
Advertising the LSP Metric in Summary LSAs
You can configure MPLS and OSPF to treat an LSP as a link. This configuration allows
other routers in the network to use this LSP. To accomplish this goal, you need to configure
MPLS and OSPF traffic engineering to advertise the LSP metric in summary LSAs.
For MPLS, include the traffic-engineering bgp-igp and label-switched-path statements:
traffic-engineering bgp-igp;
label-switched-path lsp-name {
to address;
}
You can include these statements at the following hierarchy levels:
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•
[edit protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls]
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For OSPF, include the lsp-metric-into-summary statement:
lsp-metric-into-summary;
You can include this statement at the following hierarchy levels:
•
[edit protocols ospf traffic-engineering shortcuts]
•
[edit logical-systems logical-system-name protocols ospf traffic-engineering shortcuts]
For more information about OSPF traffic engineering, see the Junos OS Routing Protocols
Configuration Guide.
Enabling Interarea Traffic Engineering
The Junos OS can signal a contiguous traffic-engineered LSP across multiple OSPF areas.
The LSP signaling must be done using either nesting or contiguous signaling, as described
in RFC 4206, Label-Switched Paths (LSP) Hierarchy with Generalized Multi-Protocol Label
Switching (GMPLS) Traffic Engineering (TE). However, contiguous signaling support is
limited to just basic signaling. Reoptimization is not supported with contiguous signaling.
The following describes some of the interarea traffic engineering features:
•
Interarea traffic engineering can be enabled when the loose-hop area border routers
(ABRs) are configured on the ingress router using CSPF for the Explicit Route Object
(ERO) calculation within an OSPF area. ERO expansion is completed on the ABRs.
•
Interarea traffic engineering can be enabled when CSPF is enabled, but without ABRs
specified in the LSP configuration on the ingress router (ABRs can be automatically
designated).
•
Differentiated Services (DiffServ) traffic engineering is supported as long as the class
type mappings are uniform across multiple areas.
To enable interarea traffic engineering, include the expand-loose-hop statement in the
configuration for each LSP transit router:
expand-loose-hop;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls]
Enabling Inter-AS Traffic Engineering for LSPs
Generally, traffic engineering is possible for LSPs that meet the following conditions:
•
Both ends of the LSP are in the same OSPF area or at the same IS-IS level.
•
The two ends of the LSP are in different OSPF areas within the same autonomous
system (AS). LSPs that end in different IS-IS levels are not supported.
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•
The two ends of an explicit-path LSP are in different OSPF ASs and the autonomous
system border routers (ASBRs) are configured statically as the loose hops supported
on the explicit-path LSP. For more information, see “Configuring Explicit-Path LSPs”
on page 200.
Without statically defined ASBRs on LSPs, traffic engineering is not possible between
one routing domain, or AS, and another. However, when the ASs are under the control
of single service provider, it is possible in some cases to have traffic engineered LSPs
span the ASs and dynamically discover the OSPF ASBRs linking them (IS-IS is not
supported with this feature).
Inter-AS traffic engineered LSPs are possible as long as certain network requirements
are met, none of the limiting conditions apply, and OSPF passive mode is configured with
EBGP. Details are provided in the following sections:
•
Inter-AS Traffic Engineering Requirements on page 220
•
Inter-AS Traffic Engineering Limitations on page 220
•
Configuring OSPF Passive TE Mode on page 221
Inter-AS Traffic Engineering Requirements
The proper establishment and functioning of inter-AS traffic engineered LSPs depend
on the following network requirements, all of which must be met:
•
All ASs are under control of a single service provider.
•
OSPF is used as the routing protocol within each AS, and EBGP is used as the routing
protocol between the ASs.
•
ASBR information is available inside each AS.
•
EBGP routing information is distributed by OSPF, and an IBGP full mesh is in place
within each AS.
•
Transit LSPs are not configured on the inter-AS links, but are configured between entry
and exit point ASBRs on each AS.
•
The EBGP link between ASBRs in different ASs is a direct link and must be configured
as a passive traffic engineering link under OSPF. The remote link address itself, not the
loopback or any other link address, is used as the remote node identifier for this passive
link. For more information about OSPF passive traffic engineering mode configuration,
see “Configuring OSPF Passive TE Mode” on page 221.
In addition, the address used for the remote node of the OSPF passive traffic engineering
link must be the same as the address used for the EBGP link. For more information about
OSPF and BGP in general, see the Junos OS Routing Protocols Configuration Guide.
Inter-AS Traffic Engineering Limitations
Only LSP hierarchical, or nested, signaling is supported for inter-AS traffic engineered
LSPs. Only point-to-point LSPs are supported (there is no point-to-multipoint support).
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In addition, the following limitations apply. Any one of these conditions is sufficient to
render inter-AS traffic engineered LSPs impossible, even if the above requirements are
met.
•
The use of multihop BGP is not supported.
•
The use of policers or topologies that prevent BGP routes from being known inside the
AS is not supported.
•
Multiple ASBRs on a LAN between EBGP peers are not supported. Only one ASBR on
a LAN between EBGP peers is supported (others ASBRs can exist on the LAN, but
cannot be advertised).
•
Route reflectors or policies that hide ASBR information or prevent ASBR information
from being distributed inside the ASs are not supported.
•
Bidirectional LSPs are not supported (LSPs are unidirectional from the traffic
engineering perspective).
•
Topologies with both inter-AS and intra-AS paths to the same destination are not
supported.
In addition, several features that are routine with all LSPs are not supported with inter-AS
traffic engineering:
•
Admin group link colors are not supported.
•
Secondary standby is not supported.
•
Reoptimization is not supported.
•
Crankback on transit routers is not supported.
•
Diverse path calculation is not supported.
•
Graceful restart is not supported.
These lists of limitations or unsupported features with inter-AS traffic engineered LSPs
are not exhaustive.
Configuring OSPF Passive TE Mode
Ordinarily, interior routing protocols such as OSPF are not run on links between ASs.
However, for inter-AS traffic engineering to function properly, information about the
inter-AS link, in particular, the address on the remote interface, must be made available
inside the AS. This information is not normally included either in EBGP reachability
messages or in OSPF routing advertisements.
To flood this link address information within the AS and make it available for traffic
engineering calculations, you must configure OSPF passive mode for traffic engineering
on each inter-AS interface. You must also supply the remote address for OSPF to
distribute and include in the traffic engineering database.
To configure OSPF passive mode for traffic engineering on an inter-AS interface, include
the passive statement for the link at the [edit protocols ospf area area-id interface
interface-name] hierarchy level:
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passive {
traffic-engineering {
remote-node-id ip-address; /* IP address at far end of inter-AS link */
}
}
OSPF must be properly configured on the router. The following example configures the
inter-AS link so-1/1/0 to distribute traffic engineering information with OSPF within the
AS. The local IP address on the link is 192.168.207.1 and the remote address is 192.168.207.2.
[edit protocols ospf area 0.0.0.0]
interface so-1/1/0 {
unit 0 {
passive {
traffic-engineering {
remote-node-id 192.168.207.2;
}
}
family inet {
address 192.168.207.1;
}
}
}
Configuring MPLS to Gather Statistics
You can configure MPLS so that it periodically gathers traffic statistics about all MPLS
sessions, including transit sessions, by configuring the statistics statement. You must
configure the statistics statement if you want to collect MPLS traffic statistics using
SNMP polling of MPLS Management Information Bases (MIBs).
To enable MPLS statistics collection, include the statistics statement:
statistics {
auto-bandwidth;
file filename <files number> <size size> <world-readable | no-world-readable>;
interval seconds;
}
You can configure these statements at the following hierarchy levels:
•
[edit protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls]
The default interval is 300 seconds.
If you configure the file option, the statistics are placed in a file, with one entry per LSP.
During the specified interval, the following information is recorded in this file:
•
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The number of packets, number of bytes, packets per second, and bytes per second
transmitted by each LSP. Feature parity for the display of packet and byte statistics
for sub-LSPs of a point-to-multipoint LSP on the Junos Trio chipset is supported in
Junos OS Releases 11.1R2, 11.2R2, and 11.4.
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•
The percent of bandwidth transmitted over a given LSP in relation to the bandwidth
percentage configured for that LSP. If no bandwidth is configured for an LSP, 0 percent
is recorded in the percentage column.
At the end of each periodic report, a summary shows the current time, total number of
sessions, number of sessions read, number of sessions ignored, and read errors, if any.
Ignored sessions are typically those not in the up state or those with a reserved
(0 through 15) incoming label (typically the egress point of an LSP). The reason for a
read error appears on the same line as the entry for the LSP on which the error occurred.
Gathering statistics is an unreliable process; occasional read errors might affect their
accuracy. Sample output follows:
lsp6
0 pkt
0
lsp5
0 pkt
0
lsp6.1
34845 pkt
2926980
lsp5.1
0 pkt
0
lsp4
0 pkt
0
Dec 7 17:28:38 Total 6 sessions: 5 success,
Byte
0 pps
Byte
0 pps
Byte
1049 pps
Byte
0 pps
Byte
0 pps
0 fail, 1 ignored
0
0
88179
0
0
Bps
Bps
Bps
Bps
Bps
0
0
132
0
0
Configuring System Log Messages and SNMP Traps for LSPs
Whenever an LSP makes a transition from up to down, or down to up, and whenever an
LSP switches from one active path to another, the ingress router generates a system log
message and sends an SNMP trap. The following shows a sample system log message:
MPLS lsp sheep1 up on primary(any) Route 192.168.1.1 192.168.1.2 192.168.1.3
MPLS lsp sheep1 change on primary(any) Route 192.168.1.1 192.168.1.2 192.168.1.3
MPLS lsp sheep1 down on primary(any)
MPLS lsp sheep1 up on secondary(any) Route 192.168.1.1 192.168.1.2 192.168.1.3
MPLS lsp sheep1 change on secondary(any) to primary(any), Route 192.168.1.1
192.168.1.2 192.168.1.3
For information about the MPLS SNMP traps and the proprietary MPLS MIBs, see the
Junos OS Network Management Configuration Guide.
To generate system log messages for LSPs, include the syslog option to the log-updown
statement:
log-updown {
syslog;
}
To generate SNMP traps for LSPs, include the trap option to the log-updown statement:
log-updown {
trap;
}
To generate SNMP traps whenever an LSP path goes down, include the trap-path-down
option to the log-updown statement:
log-updown {
trap-path-down;
}
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To generate SNMP traps whenever an LSP path comes up, include the trap-path-up
option to the log-updown statement:
log-updown {
trap-path-up;
}
To disable the generation of system log messages, include the no-syslog option to the
log-updown statement:
log-updown {
no-syslog;
}
To disable the generation of SNMP traps, include the no-trap statement:
no-trap {
mpls-lsp-traps;
rfc3812-traps;
}
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls log-updown]
•
[edit logical-systems logical-system-name protocols mpls log-updown]
For scalability reasons, only the ingress router generates SNMP traps. By default, MPLS
issues traps for all configured LSPs. If you have many LSPs, the number of traps can
become quite large. To disable the generation of SNMP traps, configure the no-trap
statement.
The no-trap statement also includes the following options which allow you to block
certain categories of MPLS SNMP traps:
•
mpls-lsp-traps—Blocks the MPLS LSP traps defined in the jnx-mpls.mib, but allows
the rfc3812.mib traps.
•
rfc-3812-traps—Blocks the traps defined in the rfc3812.mib, but allows the MPLS LSP
traps defined in the jnx-mpls.mib.
Configuring MPLS Firewall Filters and Policers
You can configure an MPLS firewall filter to count packets based on the EXP bits for the
top-level MPLS label in a packet. You can also configure policers for MPLS LSPs.
The following sections discuss MPLS firewall filters and policers:
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•
Configuring MPLS Firewall Filters on page 225
•
Examples: Configuring MPLS Firewall Filters on page 226
•
Configuring Policers for LSPs on page 226
•
Example: Configuring an LSP Policer on page 228
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•
Configuring Automatic Policers on page 228
•
Writing Different DSCP and EXP Values in MPLS-Tagged IP Packets on page 232
Configuring MPLS Firewall Filters
You can configure an MPLS firewall filter to count packets based on the EXP bits for the
top-level MPLS label in a packet. You can then apply this filter to a specific interface.
You can also configure a policer for the MPLS filter to police (that is, rate-limit) the traffic
on the interface to which the filter is attached. You cannot apply MPLS firewall filters to
Ethernet (fxp0) or loopback (lo0) interfaces.
You can configure an MPLS firewall filter on the M Series Multiservice Edge Routers and
the T Series Core Routers.
You can configure the following match criteria attributes for MPLS filters at the [edit
firewall family mpls filter filter-name term term-name from] hierarchy level:
•
exp
•
exp-except
These attributes can accept EXP bits in the range 0 through 7. You can configure the
following choices:
•
A single EXP bit—for example, exp 3;
•
Several EXP bits—for example, exp 0, 4;
•
A range of EXP bits—for example, exp [0-5];
If you do not specify a match criterion (that is, you do not configure the from statement
and use only the then statement with the count action keyword), all the MPLS packets
passing through the interface on which the filter is applied will be counted.
You also can configure any of the following action keywords at the [edit firewall family
mpls filter filter-name term term-name then] hierarchy level:
•
count
•
accept
•
discard
•
next
•
policer
For more information about how to configure firewall filters, see the Junos OS Routing
Policy Configuration Guide. For more information about how to configure interfaces, see
the Junos OS Network Interfaces Configuration Guide and the Junos OS Services Interfaces
Configuration Guide.
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Examples: Configuring MPLS Firewall Filters
The following examples illustrate how you might configure an MPLS firewall filter and
then apply the filter to an interface. This filter is configured to count MPLS packets with
EXP bits set to either 0 or 4.
The following shows a configuration for an MPLS firewall filter:
[edit firewall]
family mpls {
filter expf {
term expt0 {
from {
exp 0,4;
}
then {
count counter0;
accept;
}
}
}
}
The following shows how to apply the MPLS firewall filter to an interface:
[edit interfaces]
so-0/0/0 {
mtu 4474;
encapsulation ppp;
sonet-options {
fcs 32;
}
unit 0 {
point-to-point;
family mpls {
filter {
input expf;
output expf;
}
}
}
}
The MPLS firewall filter is applied to the input and output of an interface (see the input
and output statements in the preceding example).
Configuring Policers for LSPs
MPLS LSP policing allows you to control the amount of traffic forwarded through a
particular LSP. Policing helps to ensure that the amount of traffic forwarded through an
LSP never exceeds the requested bandwidth allocation. LSP policing is supported on
regular LSPs, LSPs configured with DiffServ-aware traffic engineering, and multiclass
LSPs. You can configure multiple policers for each multiclass LSP. For regular LSPs, each
LSP policer is applied to all of the traffic traversing the LSP. The policer's bandwidth
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limitations become effective as soon as the total sum of traffic traversing the LSP exceeds
the configured limit.
You configure the multiclass LSP and DiffServ-aware traffic engineering LSP policers in
a filter. The filter can be configured to distinguish between the different class types and
apply the relevant policer to each class type. The policers distinguish between class types
based on the EXP bits.
You configure LSP policers under the family any filter. The family any filter is used because
the policer is applied to traffic entering the LSP. This traffic might be from different
families: IPv6, MPLS, and so on. You do not need to know what sort of traffic is entering
the LSP, as long as the match conditions apply to all types of traffic.
You can configure only those match conditions that apply across all types of traffic. The
following are the supported match conditions for LSP policers:
•
forwarding-class
•
packet-length
•
interface
•
interface-set
To enable a policer on an LSP, first you need to configure a policing filter and then include
it in the LSP configuration. For information about how to configure policers, see the Junos
OS Routing Policy Configuration Guide.
To configure a policer for an LSP, specify a filter by including the filter option to the policing
statement:
policing {
filter filter-name;
}
You can include the policing statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name]
•
[edit protocols mpls static-label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls static-label-switched-path
lsp-name]
LSP Policer Limitations
When configuring MPLS LSP policers, be aware of the following limitations:
•
LSP policers are supported for packet LSPs only.
•
LSP policers are supported for unicast next hops only. Multicast next hops are not
supported.
•
LSP policers are not supported on aggregated interfaces.
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•
The LSP policer runs before any output filters.
•
Traffic sourced from the Routing Engine (for example, ping traffic) does not take the
same forwarding path as transit traffic. This type of traffic cannot be policed.
•
LSP policers work on all T Series routers and on M Series routers that have the Internet
Processor II application-specific integrated circuit (ASIC).
Example: Configuring an LSP Policer
The following example shows how you can configure a policing filter for an LSP:
[edit firewall]
policer police-ct1 {
if-exceeding {
bandwidth-limit 50m;
burst-size-limit 1500;
}
then {
discard;
}
}
policer police-ct0 {
if-exceeding {
bandwidth-limit 200m;
burst-size-limit 1500;
}
then {
discard;
}
}
family any {
filter bar {
term discard-ct0 {
then {
policer police-ct0;
accept;
}
}
}
term discard-ct1 {
then {
policer police-ct1;
accept;
}
}
}
Configuring Automatic Policers
Automatic policing of LSPs allows you to provide strict service guarantees for network
traffic. Such guarantees are especially useful in the context of Differentiated Services
for traffic engineered LSPs, providing better emulation for ATM wires over an MPLS
network. For more information about Differentiated Services for LSPs, see “DiffServ-Aware
Traffic Engineering Introduction” on page 170.
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Differentiated Services for traffic engineered LSPs allow you to provide differential
treatment to MPLS traffic based on the EXP bits. To ensure these traffic guarantees, it
is insufficient to simply mark the traffic appropriately. If traffic follows a congested path,
the requirements might not be met.
LSPs are guaranteed to be established along paths where enough resources are available
to meet the requirements. However, even if the LSPs are established along such paths
and are marked properly, these requirements cannot be guaranteed unless you ensure
that no more traffic is sent to an LSP than there is bandwidth available.
It is possible to police LSP traffic by manually configuring an appropriate filter and applying
it to the LSP in the configuration. However, for large deployments it is cumbersome to
configure thousands of different filters. Configuration groups cannot solve this problem
either, since different LSPs might have different bandwidth requirements, requiring
different filters. To police traffic for numerous LSPs, it is best to configure automatic
policers.
When you configure automatic policers for LSPs, a policer is applied to all of the LSPs
configured on the router. However, you can disable automatic policing on specific LSPs.
NOTE: You cannot configure automatic policing for LSPs carrying CCC traffic.
The following sections describe how to configure automatic policers for LSPs:
•
Configuring Automatic Policers for LSPs on page 229
•
Configuring Automatic Policers for DiffServ-Aware Traffic Engineering LSPs on page 230
•
Configuring Automatic Policers for Point-to-Multipoint LSPs on page 230
•
Disabling Automatic Policing on an LSP on page 231
•
Example: Configuring Automatic Policing for an LSP on page 231
Configuring Automatic Policers for LSPs
To configure automatic policers for standard LSPs (neither DiffServ-aware traffic
engineered LSPs nor multiclass LSPs), include the auto-policing statement with either
the class all policer-action option or the class ct0 policer-action option:
auto-policing {
class all policer-action;
class ct0 policer-action;
}
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls]
You can configure the following policer actions for automatic policers:
•
drop—Drop all packets.
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•
loss-priority-high—Set the packet loss priority (PLP) to high.
•
loss-priority-low—Set the PLP to low.
These policer actions are applicable to all types of LSPs. The default policer action is to
do nothing.
Automatic policers for LSPs police traffic based on the amount of bandwidth configured
for the LSPs. You configure the bandwidth for an LSP using the bandwidth statement at
the [edit protocols mpls label-switched-path lsp-path-name] hierarchy level. If you have
enabled automatic policers on a router, change the bandwidth configured for an LSP,
and commit the revised configuration, the change does not take affect on the active
LSPs. To force the LSPs to use the new bandwidth allocation, issue a clear mpls lsp
command.
NOTE: You cannot configure automatic policers for LSPs that traverse
aggregated interfaces or Multilink Point-to-Point Protocol (MLPPP) interfaces.
Configuring Automatic Policers for DiffServ-Aware Traffic Engineering LSPs
To configure automatic policers for DiffServ-aware traffic engineering LSPs and for
multiclass LSPs, include the auto-policing statement:
auto-policing {
class all policer-action;
class ctnumber policer-action;
}
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls]
You include either the class all policer-action statement or a class ctnumber policer-action
statement for each of one or more classes (you can configure a different policer action
for each class). For a list of the actions that you can substitute for the policer-action
variable, see “Configuring Automatic Policers for LSPs” on page 229. The default policer
action is to do nothing.
NOTE: You cannot configure automatic policers for LSPs that traverse
aggregated interfaces or MLPPP interfaces.
Configuring Automatic Policers for Point-to-Multipoint LSPs
You can configure automatic policers for point-to-multipoint LSPs by including the
auto-policing statement with either the class all policer-action option or the class ct0
policer-action option. You only need to configure the auto-policing statement on the
primary point-to-multipoint LSP (for more information on primary point-to-multipoint
LSPs, see “Configuring the Primary Point-to-Multipoint LSP” on page 204). No additional
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configuration is required on the subLSPs for the point-to-multipoint LSP.
Point-to-multipoint automatic policing is applied to all branches of the point-to-multipoint
LSP. In addition, automatic policing is applied to any local VRF interfaces that have the
same forwarding entry as a point-to-multipoint branch. Feature parity for automatic
policers for MPLS point-to-multipoint LSPs on the Junos Trio chipset is supported in
Junos OS Releases 11.1R2, 11.2R2, and 11.4.
The automatic policer configuration for point-to-multipoint LSPs is identical to the
automatic policer configuration for standard LSPs. For more information, see “Configuring
Automatic Policers for LSPs” on page 229.
Disabling Automatic Policing on an LSP
When you enable automatic policing, all of the LSPs on the router or logical system are
affected. To disable automatic policing on a specific LSP on a router where you have
enabled automatic policing, include the policing statement with the no-auto-policing
option:
policing no-auto-policing;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name]
Example: Configuring Automatic Policing for an LSP
Configure automatic policing for a multiclass LSP, specifying different actions for class
types ct0, ct1, ct2, and ct3.
[edit protocols mpls]
diffserv-te {
bandwidth-model extended-mam;
}
auto-policing {
class ct1 loss-priority-low;
class ct0 loss-priority-high;
class ct2 drop;
class ct3 loss-priority-low;
}
traffic-engineering bgp-igp;
label-switched-path sample-lsp {
to 3.3.3.3;
bandwidth {
ct0 11;
ct1 1;
ct2 1;
ct3 1;
}
}
interface fxp0.0 {
disable;
}
interface t1-0/5/3.0;
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interface t1-0/5/4.0;
Writing Different DSCP and EXP Values in MPLS-Tagged IP Packets
You can selectively set the DiffServ code point (DSCP) field of MPLS-tagged IPv4 and
IPv6 packets to 0 without affecting output queue assignment, and continue to set the
MPLS EXP field according to the configured rewrite table, which is based on forwarding
classes. You can accomplish this by configuring a firewall filter for the MPLS-tagged
packets.
For instructions on how to write different DSCP and EXP values in MPLS-tagged IP
packets, see the Junos OS Class of Service Configuration Guide. For instructions on how to
configure firewall filters, see the Junos OS Routing Policy Configuration Guide.
Configuring MPLS Rewrite Rules
You can apply a number of different rewrite rules to MPLS packets.
For more information about how to configure statements at the [edit class-of-service]
hierarchy level, see the Junos OS Class of Service Configuration Guide.
The following sections describe how you can apply rewrite rules to MPLS packets:
•
Rewriting the EXP Bits of All Three Labels of an Outgoing Packet on page 232
•
Rewriting MPLS and IPv4 Packet Headers on page 233
Rewriting the EXP Bits of All Three Labels of an Outgoing Packet
In interprovider, carrier-of-carrier, and complex traffic engineering scenarios, it is
sometimes necessary to push three labels on the next hop.
By default, on M Series routers except the M320, the top MPLS EXP label of an outgoing
packet is not rewritten when you configure swap-push-push and triple-push operations.
You can rewrite the EXP bits of all three labels of an outgoing packet, thereby maintaining
the class of service (CoS) of an incoming MPLS or non-MPLS packet.
To push three labels on incoming MPLS packets, include the exp-swap-push-push default
statement at the [edit class-of-service interfaces interface-name unit logical-unit-number
rewrite-rules] hierarchy level:
[edit class-of-service interfaces interface-name unit logical-unit-number rewrite-rules]
exp-swap-push-push default;
To push three labels on incoming non-MPLS packets, include the exp-push-push-push
default statement at the [edit class-of-service interfaces interface-name unit
logical-unit-number rewrite-rules] hierarchy level:
[edit class-of-service interfaces interface-name unit logical-unit-number rewrite-rules]
exp-push-push-push default;
For more information about how to configure statements at the [edit class-of-service]
hierarchy level, see the Junos OS Class of Service Configuration Guide.
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Rewriting MPLS and IPv4 Packet Headers
You can apply a rewrite rule to MPLS and IPv4 packet headers simultaneously. This
allows you to initialize MPLS EXP and IP precedence bits at LSP ingress. You can configure
different rewrite rules depending on whether the traffic is VPN or non-VPN.
To rewrite MPLS and IPv4 packet headers, include the protocol statement at the
[edit class-of-service interfaces interface-name unit logical-unit-number rewrite-rules exp
rewrite-rule-name] hierarchy level:
[edit class-of-service interfaces interface-name unit logical-unit-number rewrite-rules exp
rewrite-rule-name]
protocol types;
Use the protocol statement to specify the types of MPLS packets and packet headers
to which to apply the rewrite rule. The MPLS packet can be a standard MPLS packet or
an MPLS packet with an IPv4 payload. Specify the type of MPLS packet by using the
following options:
•
mpls-any—Applies the rewrite rule to MPLS packets and writes the code point value
to MPLS headers.
•
mpls-inet-both—Applies the rewrite rule to VPN MPLS packets with IPv4 payloads.
Writes the code point value to the MPLS and IPv4 headers in T Series and M320 routers.
On M Series routers, except the M320, the mpls-inet-both option causes all ingress
MPLS LSP packets with IPv4 payloads to be initialized with 000 code points for IP
precedence and MPLS EXP values.
•
mpls-inet-both-non-vpn—Applies the rewrite rule to any non-VPN MPLS packets with
IPv4 payloads. Writes the code point value to the MPLS and IPv4 headers in T Series
and M320 routers. On M Series routers, except the M320, the mpls-inet-both-non-vpn
option causes all ingress MPLS LSP packets with IPv4 payloads to be initialized with
000 code points for IP precedence and MPLS EXP values.
For a detailed example on how to configure rewrite rules for MPLS and IPv4 packets and
for more information about how to configure class of service, see the Junos OS Class of
Service Configuration Guide.
Configuring BFD for MPLS IPv4 LSPs
You can configure Bidirectional Forwarding Detection (BFD) protocol on MPLS IPv4 LSPs
as outlined in the Internet draft draft-ietf-bfd-mpls-02.txt, BFD for MPLS LSPs. BFD is
used as a periodic Operation, Administration, and Maintenance (OAM) feature for LSPs
to detect LSP data plane faults. You can configure BFD for LSPs that use either LDP or
RSVP as the signaling protocol.
You can also use the LSP ping commands to detect LSP data plane faults. However,
BFD has a couple of benefits: it requires less computer processing than LSP ping
commands and can quickly detect faults in large numbers of LSPs (LSP ping commands
must be issued for each LSP individually). On the other hand, BFD cannot be used to
verify the control plane against the data plane at the egress LSR, which is possible when
an LSP ping echo request is associated with a forwarding equivalence class (FEC).
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For configuration instructions for LDP-signaled LSPs, see “Configuring BFD for LDP LSPs”
on page 448. For configuration instructions for RSVP-signaled LSPs, see the following
section.
Configuring BFD for RSVP-Signaled LSPs
BFD for RSVP supports unicast IPv4 LSPs. When BFD is configured for an RSVP LSP on
the ingress router, it is enabled on the primary path and on all standby secondary paths
for that LSP. You can enable BFD for all LSPs on a router or for specific LSPs. If you
configure BFD for a specific LSP, whatever values configured globally for BFD are
overridden. The BFD sessions originate only at the ingress router and terminate at the
egress router.
An error is logged whenever a BFD session for a path fails. The following example shows
how BFD for RSVP LSP log messages might appear:
RPD_MPLS_PATH_BFD_UP: MPLS BFD session for path path1 up on LSP R0_to_R3
RPD_MPLS_PATH_BFD_DOWN: MPLS BFD session for path path1 down on LSP R0_to_R3
You can configure BFD for all of the RSVP LSPs on the router, a specific LSP, or the
primary path of a specific LSP. To configure BFD for RSVP LSPs, include the oam and
bfd-liveness-detection statements.
oam {
bfd-liveness-detection {
failure-action {
make-before-break teardown-timeout seconds;
teardown;
}
failure-action teardown;
minimum-interval milliseconds;
minimum-receive-interval milliseconds;
minimum-transmit-interval milliseconds;
multiplier detection-time-multiplier;
}
lsp-ping-interval seconds;
}
You can configure this statement at the following hierarchy levels:
•
[edit protocols mpls]
•
[edit protocols mpls label-switched-path lsp-name]
•
[edit protocols mpls label-switched-path lsp-name primary path-name]
The bfd-liveness-detection statement includes the following options:
•
minimum-interval—Specifies the minimum transmit and receive interval.
•
minimum-receive-interval—Specifies the minimum receive interval. The range is from
1 through 255,000 milliseconds.
•
minimum-transmit-interval—Specifies the minimum transmit interval. The range is
from 1 through 255,000 milliseconds.
•
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multiplier—Specifies the detection time multiplier. The range is from 1 through 255.
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NOTE: To avoid triggering false negatives, configure a BFD fault detection
time that is longer than the fast reroute time.
You can also configure the lsp-ping-interval option to adjust the time interval between
LSP pings. The LSP ping command for RSVP-signaled LSPs is ping mpls rsvp. For more
information on the ping mpls rsvp command, see the Junos OS System Basics and Services
Command Reference.
Configuring a Failure Action for the BFD Session on an RSVP LSP
When the BFD session for an RSVP LSP goes down, the LSP is torn down and resignaled.
Traffic can be switched to a standby LSP, or you can simply tear down the LSP path. Any
actions performed are logged.
When a BFD session for an RSVP LSP path goes down, you can configure the Junos OS
to resignal the LSP path or to simply disable the LSP path. A standby LSP path could be
configured to handle traffic while the primary LSP path is unavailable. The router can
automatically recover from LSP failures that can be detected by BFD. By default, if a BFD
session fails, the event is simply logged.
To enable the Junos OS to tear down an RSVP LSP path in the event of a BFD event,
include the failure-action statement:
failure-action {
make-before-break teardown-timeout seconds;
teardown;
}
For a list of the hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
You can configure either the teardown or make-before-break options:
•
teardown—Causes the LSP path to be taken down and resignaled immediately.
•
make-before-break—Causes the Junos OS to attempt to signal a new LSP path before
tearing down the old LSP path. You can also configure the teardown-timeout option
to automatically tear down the LSP after the time period specified if the attempt to
resignal the LSP fails within the teardown-timeout interval. If you specify a value of 0
for the teardown-timeout interval, the LSP is taken down and resignaled immediately
(the same behavior as when you configure the teardown option).
To configure a failure action for all of the RSVP LSPs, include the failure-action statement
at the [edit protocols mpls oam bfd-liveness-detection] hierarchy level. To configure a
failure action for a specific RSVP LSP, include the failure-action statement at the [edit
protocols mpls label-switched-path lsp-name oam bfd-liveness-detection] hierarchy level.
To configure a failure action for a specific primary path, include the failure-action
statement at the [edit protocols mpls label-switched path lsp-name primary path-name
oam bfd-liveness-detection] hierarchy level. To configure a failure action for a specific
secondary LSP path, include the failure-action statement at the [edit protocols mpls
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label-switched-path lsp-name secondary path-name oam bfd-liveness-detection] hierarchy
level.
Pinging LSPs
The following sections describe how to use the ping mpls command to confirm LSP
functioning.
•
Pinging MPLS LSPs on page 236
•
Pinging Point-to-Multipoint LSPs on page 236
•
Pinging the Endpoint Address of MPLS LSPs on page 237
•
Pinging CCC LSPs on page 237
•
Pinging Layer 3 VPNs on page 237
•
Support for LSP Ping and Traceroute Commands Based on RFC 4379 on page 237
Pinging MPLS LSPs
You can ping a specific LSP. Echo requests are sent over the LSP as MPLS packets. The
payload is a User Datagram Protocol (UDP) packet forwarded to an address in the 127/8
range (127.0.0.1 by default, this address is configurable) and port 3503. The label and
interface information for building and sending this information as an MPLS packet is the
same as for standard LSP traffic.
When the echo request arrives at the egress node, the receiver checks the contents of
the packet and sends a reply containing the correct return value, by using UDP. The router
sending the echo request waits to receive an echo reply after a timeout of 2 seconds (you
cannot configure this value).
You must configure MPLS at the [edit protocols mpls] hierarchy level on the remote router
to be able to ping an LSP terminating there. You must configure MPLS even if you intend
to ping only LDP forwarding equivalence classes (FECs).
To ping an MPLS LSP use the ping mpls <count count> <ldp <fec>> <rsvp <exp
forwarding-class> <lsp-name>> command. To ping a secondary MPLS LSP, use the ping
mpls <count count> <rsvp <lsp-name>> standby path-name command. For a detailed
description of this command, see the Junos OS Routing Protocols and Policies Command
Reference.
NOTE: The ping mpls command is not supported within routing instances.
Pinging Point-to-Multipoint LSPs
To ping a point-to-multipoint LSP, use the ping mpls rsvp lsp-name multipoint or ping
mpls rsvp egress address commands. The ping mpls rsvp lsp-name multipoint command
returns a list of all of the egress router identifiers and the current status of the
point-to-multipoint LSP egress routers. The ping mpls rsvp lsp-name multipoint egress
address command returns the current status of the specified egress router.
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Pinging the Endpoint Address of MPLS LSPs
To determine whether an LSP between two provider edge (PE) routers is up and running,
you can ping the endpoint address of the LSP. To ping an MPLS LSP endpoint, use the
ping mpls lsp-end-point address command. This command tells you what type of LSP
(RSVP or LDP) terminates at the address specified and whether that LSP is up or down.
For a detailed description of this command, see the Junos OS Routing Protocols and Policies
Command Reference.
Pinging CCC LSPs
You can ping a specific CCC LSP. The CCC LSP ping command is identical to the one
used for MPLS LSPs. The command you use is ping mpls <count count> <rsvp <lsp-name>>.
You can also ping a secondary standby CCC LSP by using the ping mpls <count count>
<rsvp <lsp-name>> standby path-name command.
For a detailed description of this command, see the Junos OS Routing Protocols and Policies
Command Reference.
Pinging Layer 3 VPNs
You can use a similar command, ping mpls l3vpn vpn-name prefix prefix <count count>,
to ping a Layer 3 VPN. For more information about this command, see the Junos OS VPNs
Configuration Guide and the Junos OS Routing Protocols and Policies Command Reference.
Support for LSP Ping and Traceroute Commands Based on RFC 4379
The Junos OS partially supports LSP ping and traceroute commands based on RFC 4379,
Detecting Multi-Protocol Label Switched (MPLS) Data Plane Failures. However, the Junos
OS only supports this functionality on LSP transit routers. If a ping or traceroute command
is issued from a router that fully supports RFC 4379, it can propagate correctly on routers
running the Junos OS.
LSP ping and traceroute commands based on RFC 4379 attempt to trace the path taken
by an LSP by relying on MPLS TTL expiration. An LSP can take multiple paths from ingress
to egress. This occurs in particular with Equal Cost Multipath (ECMP). The LSP traceroute
command can trace all possible paths to an LSP egress node.
Tracing MPLS and LSP Packets and Operations
To trace MPLS and LSP packets and operations, include the traceoptions statement:
traceoptions {
file filename <files number> <size size> <world-readable | no-world-readable>;
flag flag;
}
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
You can specify the following MPLS-specific flags in the MPLS traceoptions statement:
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•
all—Trace all operations.
•
connection—Trace all circuit cross-connect (CCC) activity.
•
connection-detail—Trace detailed CCC activity.
•
cspf—Trace CSPF computations.
•
cspf-link—Trace links visited during CSPF computations.
•
cspf-node—Trace nodes visited during CSPF computations.
•
error—Trace MPLS error conditions.
•
graceful-restart—Trace MPLS graceful restart events.
•
lsping—Trace LSP ping packets and return codes.
•
nsr-synchronization—Trace nonstop routing (NSR) synchronization events.
•
nsr-synchronization-detail—Trace NSR synchronization events in detail.
•
state—Trace all LSP state transitions.
•
static—Trace static label-switched path.
When you configure trace options to track an MPLS LSP using the cspf option, the CSPF
log displays information about the MPLS LSP using the term “generalized MPLS” (GMPLS).
For example, a message in the CSPF log might state that the “link passes GMPLS
constraints”. Generalized MPLS (GMPLS) is a superset of MPLS, so this message is normal
and does not affect proper MPLS LSP operation.
For general information about tracing and global tracing options, see the Junos OS Routing
Protocols Configuration Guide.
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CHAPTER 10
Summary of MPLS Configuration
Statements
This chapter shows the complete MPLS configuration statements. The statements are
organized alphabetically.
adaptive
Syntax
Hierarchy Level
Release Information
Description
Default
Required Privilege
Level
Related
Documentation
adaptive;
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
(primary | secondary) path-name],
[edit protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name (primary | secondary) path-name]
Statement introduced before Junos OS Release 7.4.
During reroute, do not double-count bandwidth on links shared by the old and new paths.
Including this statement causes RSVP to use shared explicit (SE) reservation styles and
assists in smooth transition during rerouting.
The configured object is disabled.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Adaptive LSPs on page 159
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adjust-interval
Syntax
Hierarchy Level
Release Information
Description
Options
adjust-interval seconds;
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
auto-bandwidth],
[edit protocols mpls label-switched-path lsp-name auto-bandwidth]
Statement introduced before Junos OS Release 7.4.
Specify the bandwidth reallocation interval.
seconds—Bandwidth reallocation interval, in seconds.
Range: 300 through 4,294,967,295 seconds
Default: 86,400 seconds
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Automatic Bandwidth Allocation Interval on page 147
adjust-threshold
Syntax
Hierarchy Level
Release Information
Description
Options
adjust-threshold percent;
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
auto-bandwidth],
[edit protocols mpls label-switched-path lsp-name auto-bandwidth]
Statement introduced before Junos OS Release 7.4.
Specify how sensitive the automatic bandwidth adjustment for a label-switched path
(LSP) is to changes in bandwidth utilization.
percent—Bandwidth demand for the current bandwidth adjustment interval is determined
and compared to the LSP’s current bandwidth allocation. If the percentage difference
in bandwidth is greater than or equal to the percentage specified by this statement,
the LSP’s bandwidth is adjusted to the current bandwidth demand.
Required Privilege
Level
Related
Documentation
240
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Automatic Bandwidth Adjustment Threshold on page 148
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Chapter 10: Summary of MPLS Configuration Statements
adjust-threshold-overflow-limit
Syntax
Hierarchy Level
Release Information
Description
Options
adjust-threshold-overflow-limit number;
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
auto-bandwidth],
[edit protocols mpls label-switched-path lsp-name auto-bandwidth]
Statement introduced in Junos OS Release 7.5.
Specify the number of consecutive bandwidth overflow samples before triggering a
bandwidth adjustment.
number—Number of consecutive bandwidth overflow samples.
Range: 1 through 65,535
Default: This feature is disabled by default.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring a Limit on Bandwidth Overflow Samples on page 149
admin-down
Syntax
Hierarchy Level
Release Information
Description
Required Privilege
Level
Related
Documentation
admin-down;
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name]
Statement introduced in Junos OS Release 8.2.
Set a nonpacket GMPLS LSP to the administrative down state. This statement does not
affect control path setup or data forwarding for packet LSPs.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Allowing Nonpacket GMPLS LSPs to Establish Paths Through Routers Running the
Junos OS on page 559
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admin-group
See the following sections:
•
admin-group (for Interfaces) on page 242
•
admin-group (for LSPs) on page 243
admin-group (for Interfaces)
Syntax
Hierarchy Level
Release Information
Description
Options
admin-group [ group-names ];
[edit logical-systems logical-system-name protocols mpls interface interface-name],
[edit protocols mpls interface interface-name]
Statement introduced before Junos OS Release 7.4.
Define administrative groups for an interface.
group-names—One or more names of groups defined with the admin-groups statement
at the [edit protocols mpls] hierarchy level.
Required Privilege
Level
Related
Documentation
242
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Administrative Groups on page 153
•
admin-groups on page 244
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Chapter 10: Summary of MPLS Configuration Statements
admin-group (for LSPs)
Syntax
Hierarchy Level
Release Information
Description
Options
Required Privilege
Level
Related
Documentation
admin-group {
exclude [ group-names ];
include-all [ group-names ];
include-any [ group-names ];
}
[edit logical-systems logical-system-name protocols mpls],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
(primary | secondary) path-name],
[edit protocols mpls],
[edit protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name (primary | secondary) path-name]
Statement introduced before Junos OS Release 7.4.
Define the administrative groups to include or exclude an LSP and a path’s primary and
secondary paths.
The statements are explained separately.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Administrative Groups on page 153
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admin-groups
Syntax
Hierarchy Level
Release Information
Description
Options
admin-groups {
group-name group-value;
}
[edit logical-systems logical-system-name protocols mpls],
[edit protocols mpls]
Statement introduced before Junos OS Release 7.4.
Configure administrative groups to implement link coloring of resource classes.
group-name—Name of the group. You can assign up to 32 names. The names and their
corresponding values must be identical across all routers within a single domain.
group-value—Value assigned to the group. The names and their corresponding values
must be identical across all routers within a single domain.
Range: 0 through 31
Required Privilege
Level
Related
Documentation
244
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Administrative Groups on page 153
•
admin-group (for Interfaces) on page 242
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
admin-group-extended
Syntax
Hierarchy Level
Release Information
Description
Options
admin-group-extended {
apply-groups group-value;
apply-groups-except group-value;
exclude [ group-values ];
include-all [ group-values ];
include-any [ group-values ];
}
[edit logical-systems logical-system-name protocols mpls],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
(primary | secondary) path-name],
[edit protocols mpls],
[edit protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name (primary | secondary) path-name]
Statement introduced in Junos OS Release 11.1.
Specifies the group name and group identifier for an administrative group. The group
identifier must be within the range of values specified by the admin-groups-extended-range
statement. The extended administrative group values are global and must be identically
configured on all the supported routers participating in the network. The domain-wide
extended administrative groups database, learned from other routers through IGP flooding,
is used by CSPF for path computation.
apply-groups—Apply the specified administrative groups for the LSP or for the primary
and secondary paths.
apply-groups-except—Exclude the specified administrative groups from the LSP or from
the primary and secondary paths.
exclude—Define the administrative groups to exclude from an LSP or from the primary
and secondary paths.
include-all—Require the LSP to traverse links that include all of the defined administrative
groups.
include-any—Define the administrative groups to include for an LSP for the primary and
secondary paths.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Extended Administrative Groups on page 155
•
Configuring Administrative Groups on page 153
•
admin-groups-extended on page 246
•
admin-groups-extended-range on page 247
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
admin-groups-extended
Syntax
Hierarchy Level
Release Information
Description
Options
admin-groups-extended group-name {
group-value group-identifier;
}
[edit logical-systems logical-system-name protocols mpls interface interface-name],
[edit logical-systems logical-system-name routing-options],
[edit protocols mpls interface interface-name],
[edit routing-options]
Statement introduced in Junos OS Release 11.1.
Specifies the group name and group identifier for an administrative group. The group
identifier must be within the range of values specified by the admin-groups-extended-range
statement. The extended administrative group values are global and must be identically
configured on all the supported routers participating in the network. The domain-wide
extended administrative groups database, learned from other routers through IGP flooding,
is used by CSPF for path computation.
group-name—The range of configurable values is between 32 and 4,294,967,295. The
range maximum must be greater than the range minimum.
group-value group-identifier—The group identifier must be within the range of configurable
values, 32 and 4,294,967,295.
Required Privilege
Level
Related
Documentation
246
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Extended Administrative Groups on page 155
•
Configuring Administrative Groups on page 153
•
admin-group-extended on page 245
•
admin-groups-extended-range on page 247
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
admin-groups-extended-range
Syntax
Hierarchy Level
Release Information
Description
admin-groups-extended-range {
maximum maximum-number;
mininum minimum-number;
}
[edit logical-systems logical-system-name routing-options],
[edit routing-options]
Statement introduced in Junos OS Release 11.1.
Enables you to configure extended administrative groups, represented by a 32-bit value,
expanding the number of administrative groups supported in the network beyond just
32. In MPLS traffic engineering, a link can be configured with a set of administrative groups
(also known as colors or resource classes). Administrative groups are carried in IGPs
(OSPFv2 and IS-IS) as a 32-bit value assigned to each link. By default, Juniper Networks
routers interpret this 32-bit value as a bit mask with each bit representing a group. This
normally limits each network to a total of 32 distinct administrative groups (value range
0 through 31).
The extended administrative groups configuration accepts a set of interfaces with a
corresponding set of extended administrative group names. It converts the names into
a set of 32-bit values and propagates this information into the IGP. The extended
administrative group values are global and must be identically configured on all the
supported routers participating in the network. The domain-wide extended administrative
groups database, learned from other routers through IGP flooding, is used by CSPF for
path computation.
Options
maximum maximum-number—The range of configurable values is between 32 and
4,294,967,295. The range maximum must be greater than the range minimum.
minimum minimum-number—The range of configurable values is between 32 and
4,294,967,295. The range maximum must be greater than the range minimum.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Extended Administrative Groups on page 155
•
Configuring Administrative Groups on page 153
•
admin-group-extended on page 245
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
advertisement-hold-time
Syntax
Hierarchy Level
Release Information
Description
Options
advertisement-hold-time seconds;
[edit logical-systems logical-system-name protocols mpls],
[edit protocols mpls]
Statement introduced before Junos OS Release 7.4.
Do not advertise when the LSP goes from up to down, for a certain period of time known
as the hold time.
seconds—Hold time, in seconds.
Range: 0 through 65,535 seconds
Default: 5 seconds
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Damping Advertisement of LSP State Changes on page 167
allow-fragmentation
Syntax
Hierarchy Level
Release Information
Description
Required Privilege
Level
Related
Documentation
248
allow-fragmentation;
[edit logical-systems logical-system-name protocols mpls path-mtu],
[edit protocols mpls path-mtu]
Statement introduced before Junos OS Release 7.4.
Allow IP packets to be fragmented before they are encapsulated in MPLS.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Enabling Packet Fragmentation on page 381
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
always-mark-connection-protection-tlv
Syntax
Hierarchy Level
Release Information
Description
always-mark-connection-protection-tlv;
[edit logical-systems logical-systems-name protocols mpls interface interface-name],
[edit protocols mpls interface interface-name]
Statement introduced in Junos OS Release 10.2.
(MX Series routers only) Enable you to switch an LSP away from a network node using
a bypass LSP. This feature could be used in maintenance of active networks when a
network device needs to be replaced without interrupting traffic passing through the
network. The LSPs can be either static or dynamic.
This statement marks all OAM traffic transiting this interface in preparation for switching
the traffic to an alternate path based on the OAM functionality. To switch traffic to the
bypass LSP, you then need to configure the switch-away-lsps statement.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Switching LSPs Away from a Network Node on page 365
associate-backup-pe-groups
Syntax
Hierarchy Level
Release Information
Description
Required Privilege
Level
Related
Documentation
associate-backup-pe-groups;
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name]
Statement introduced in Junos OS Release 9.0.
Enable an LSP to monitor the status of its destination PE router. You can configure
multiple backup PE router groups using the same router's address. Backup PE router
groups provide ingress PE router redundancy when point-to-multipoint LSPs are
configured for multicast distribution. A failure of this LSP indicates to all of the backup
PE router groups that the destination PE router is down. This statement is not tied to a
specific backup PE router group. It applies to all groups that are interested in the status
of the LSP to the destination address.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Enabling Point-to-Point LSPs to Monitor Egress PE Routers on page 208
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
auto-bandwidth
Syntax
Hierarchy Level
Release Information
Description
Options
Required Privilege
Level
Related
Documentation
250
auto-bandwidth {
adjust-interval seconds;
adjust-threshold percent;
adjust-threshold-overflow-limit number;
maximum-bandwidth bps;
minimum-bandwidth bps;
monitor-bandwidth;
}
[edit protocols mpls label-switched-path lsp-name]
Statement introduced before Junos OS Release 7.4.
Allow an MPLS tunnel to automatically adjust its bandwidth allocation based on the
volume of traffic flowing through the tunnel.
The statements are explained separately.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Automatic Bandwidth Allocation for LSPs on page 145
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
auto-policing
Syntax
Hierarchy Level
Release Information
auto-policing {
class all (drop | loss-priority-high | loss-priority-low);
class ctnumber (drop | loss-priority-high | loss-priority-low);
}
[edit logical-systems logical-system-name protocols mpls],
[edit protocols mpls]
Statement introduced before Junos OS Release 7.4.
Description
Enable the automatic policing of all the MPLS LSPs on the router or logical system.
Options
class all—Apply the same policer action to all the class types (ct0, ct1, ct2, and ct3).
class ctnumber—Specific class type (ct0, ct1, ct2, or ct3) to which to apply a policer action.
Policer actions—You can specify the following policer actions:
Default: no action
Required Privilege
Level
Related
Documentation
•
drop—Drop all packets.
•
loss-priority-high—Set the packet loss priority (PLP) to high.
•
loss-priority-low—Set the PLP to low.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
policing on page 305
•
Configuring Automatic Policers on page 228v
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
backup-pe-group
Syntax
Hierarchy Level
Release Information
Description
Options
backup-pe-group pe-group-name {
backups [ addresses ];
local-address address;
}
[edit logical-systems logical-system-name routing-instances routing-instance-name
routing-options multicast],
[edit logical-systems logical-system-name routing-options multicast],
[edit routing-instances routing-instance-name routing-options multicast],
[edit routing-options multicast]
Statement introduced in Junos OS Release 9.0.
Configure a backup provider edge (PE) group for ingress PE router redundancy when
point-to-multipoint label-switched paths (LSPs) are used for multicast distribution.
backups addresses—Specify the address of backup PE routers for ingress PE redundancy
when point-to-multipoint LSPs are used for multicast distribution.
local-address address—Specify the address of the local PE router for ingress PE redundancy
when point-to-multipoint LSPs are used for multicast distribution.
pe-group-name—Specify the name for the group of PE routers that provide ingress PE
router redundancy for point-to-multipoint LSPs.
Required Privilege
Level
Related
Documentation
252
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Ingress PE Router Redundancy for Point-to-Multipoint LSPs on page 207
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
bandwidth (Fast Reroute, Signaled, and Multiclass LSPs)
Syntax
Hierarchy Level
Release Information
Description
bandwidth bps {
ct0 bps;
ct1 bps;
ct2 bps;
ct3 bps;
}
[edit logical-systems logical-system-name protocols mpls],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
fast-reroute],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
(primary | secondary) path-name],
[edit protocols mpls],
[edit protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name fast-reroute],
[edit protocols mpls label-switched-path lsp-name (primary | secondary) path-name]
Statement introduced before Junos OS Release 7.4.
When configuring an LSP, specify the traffic rate associated with the LSP.
When configuring fast reroute, allocate bandwidth for the reroute path. By default, no
bandwidth is reserved for the rerouted path. The fast reroute bandwidth does not need
to be identical to that allocated for the LSP itself.
When configuring a multiclass LSP, use the ctnumber bandwidth statements to specify
the bandwidth to be allocated for each class type.
Options
bps—Bandwidth, in bits per second. You can specify this as an integer value. You can also
use the abbreviations k (for a thousand), m (for a million), or g (for a billion).
Range: Any positive integer
Default: 0 (no bandwidth is reserved)
ctnumber bps—Bandwidth for the specified class type, in bits per second. You can specify
this as an integer value. If you do so, count your zeros carefully, or you can use the
abbreviations k (for a thousand), m (for a million), or g (for a billion [also called a
thousand million]).
Range: Any positive integer
Default: 0 (no bandwidth is reserved)
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Fast Reroute on page 134
•
Configuring the Bandwidth Value for LSPs on page 166
•
Configuring Traffic-Engineered LSPs on page 186
Copyright © 2011, Juniper Networks, Inc.
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•
Configuring Class-Type Bandwidth Constraints for Multiclass LSPs on page 189
bandwidth (Static LSP)
Syntax
Hierarchy Level
Release Information
Description
Options
bandwidth bps;
[edit logical-systems logical-system-name protocols mpls
static-label-switched-path lsp-name bypass],
[edit logical-systems logical-system-name protocols mpls
static-label-switched-path lsp-name ingress],
[edit logical-systems logical-system-name protocols mpls
static-label-switched-path lsp-name transit incoming-label],
[edit protocols mpls static-label-switched-path lsp-name bypass],
[edit protocols mpls static-label-switched-path lsp-name ingress],
[edit protocols mpls static-label-switched-path lsp-name transit incoming-label]
Statement introduced in Junos OS Release 10.1.
When configuring a static LSP, specify the traffic rate associated with the LSP.
bps—Bandwidth, in bits per second. You can specify this as an integer value. You can also
use the abbreviations k (for a thousand), m (for a million), or g (for a billion).
Range: Any positive integer
Default: 0 (no bandwidth is reserved)
Required Privilege
Level
Related
Documentation
254
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Static LSPs on page 193
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
bandwidth-model
Syntax
Hierarchy Level
Release Information
bandwidth-model {
extended-mam;
mam;
rdm;
}
[edit logical-systems logical-system-name protocols mpls diffserv-te],
[edit protocols mpls diffserv-te]
Statement introduced before Junos OS Release 7.4.
Description
Configure the bandwidth model for differentiated services. Note that you cannot configure
both bandwidth models at the same time.
Options
extended-mam—The extended maximum allocation model (MAM) is a bandwidth model
based on MAM.
mam—The MAM is defined in RFC 4125, Maximum Allocation Bandwidth Constraints Model
for Diffserv-aware MPLS Traffic Engineering.
rdm—The Russian dolls bandwidth allocation model (RDM) is defined in RFC 4127, Russian
Dolls Bandwidth Constraints Model for Diffserv-aware MPLS Traffic Engineering. RDM
makes efficient use of bandwidth by allowing the class types to share bandwidth.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Bandwidth Model on page 176
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
bandwidth-percent
Syntax
Hierarchy Level
Release Information
Description
Options
bandwidth-percent percentage;
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
fast-reroute],
[edit protocols mpls label-switched-path lsp-name fast-reroute]
Statement introduced before Junos OS Release 7.4.
Configure the percentage of bandwidth to reserve for the detour path in case the primary
path for a traffic engineered LSP or a multiclass LSP fails. The percentage configured
indicates the percentage of the protected path’s bandwidth that is reserved for the detour
path.
percentage—The percentage of the protected path’s bandwidth that is reserved for the
detour path.
Required Privilege
Level
Related
Documentation
256
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Fast Reroute on page 134
•
Configuring Fast Reroute for Traffic-Engineered LSPs on page 187
•
Configuring Fast Reroute for Multiclass LSPs on page 190
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
bfd-liveness-detection
Syntax
Hierarchy Level
Release Information
Description
Options
bfd-liveness-detection {
failure-action {
make-before-break teardown-timeout seconds;
teardown;
}
minimum-interval milliseconds;
minimum-receive-interval milliseconds;
minimum-transmit-interval milliseconds;
multiplier detection-time-multiplier;
}
[edit protocols mpls label-switched-path lsp-name oam],
[edit protocols mpls oam]
Statement introduced in Junos OS Release 7.6.
failure-action option added in Junos OS Release 8.5.
Enable Bidirectional Forwarding Detection (BFD) for all of the MPLS LSPs or for just a
specific LSP.
minimum-interval—Minimum transmit and receive interval.
Range: 50 through 255,000 milliseconds
Default: 50
minimum-receive-interval—Minimum receive interval.
Range: 50 through 255,000 milliseconds
Default: 50
minimum-transmit-interval—Minimum transmit interval.
Range: 50 through 255,000 milliseconds
Default: 50
multiplier—Detection time multiplier.
Range: 1 through 255
Default: 3
The failure-action statement is explained separately.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring BFD for MPLS IPv4 LSPs on page 233
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
bypass (Static LSP)
Syntax
Hierarchy Level
Release Information
Description
bypass bypass-name {
bandwidth bps;
description string;
next-hop (address | interface-name | address/interface-name);
push out-label;
to address;
}
[edit logical-systems logical-system-name protocols mpls static-label-switched-path
lsp-name],
[edit protocols mpls static-label-switched-path lsp-name]
Statement introduced before Junos OS Release 10.1.
Configure specific bandwidth and path constraints for a bypass ingress LSP. It is possible
to configure multiple bypass LSPs individually. If you do not, they all share the same path
and bandwidth constraints.
The remaining statements are explained separately.
Required Privilege
Level
Related
Documentation
258
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Static LSPs on page 193
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
class-of-service
Syntax
Hierarchy Level
Release Information
Description
class-of-service cos-value;
[edit logical-systems logical-system-name protocols mpls],
[edit logical-systems logical-system-name protocols mpls static-label-switched-path
lsp-name ingress],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
(primary | secondary) path-name],
[edit protocols mpls],
[edit protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name (primary | secondary) path-name],
[edit logical-systems logical-system-name protocols mpls static-label-switched-path
lsp-name ingress]
Statement introduced before Junos OS Release 7.4.
Class-of-service (CoS) value given to all packets in the LSP.
The CoS value might affect the scheduling or queuing algorithm of traffic traveling along
an LSP.
Options
cos-value—CoS value. A higher value typically corresponds to a higher level of service.
Range: 0 through 7
Default: If you do not specify a CoS value, the IP precedence bits from the packet’s IP
header are used as the packet’s CoS value.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Class of Service for MPLS LSPs on page 157
•
Configuring the Ingress Router for Static LSPs on page 193
•
Configuring the Intermediate (Transit) and Egress Routers for Static LSPs on page 196
Copyright © 2011, Juniper Networks, Inc.
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description
Syntax
Hierarchy Level
Release Information
description text;
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit logical-systems logical-system-name protocols mpls
static-label-switched-path lsp-name bypass],
[edit logical-systems logical-system-name protocols mpls
static-label-switched-path lsp-name ingress],
[edit logical-systems logical-system-name protocols mpls
static-label-switched-path lsp-name transit incoming-label],
[edit protocols mpls label-switched-path lsp-name],
[edit protocols mpls static-label-switched-path lsp-name bypass],
[edit protocols mpls static-label-switched-path lsp-name ingress],
[edit protocols mpls static-label-switched-path lsp-name transit incoming-label]
Statement introduced before Junos OS Release 7.4.
Description
Provides a textual description of the LSP. Enclose any descriptive text that includes
spaces in quotation marks (" "). Any descriptive text you include is displayed in the output
of the show mpls lsp detail command and has no effect on the operation of the LSP.
Options
text—Provide a textual description of the LSP. The description text can be no more than
80 characters in length.
Required Privilege
Level
Related
Documentation
260
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring a Text Description for LSPs on page 134
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
diffserv-te
Syntax
Hierarchy Level
Release Information
Description
Options
Required Privilege
Level
Related
Documentation
diffserv-te {
bandwidth-model {
extended-mam;
mam;
rdm;
}
te-class-matrix {
tenumber {
priority priority;
traffic-class {
ctnumber priority priority;
}
}
}
}
[edit logical-systems logical-system-name protocols mpls],
[edit protocols mpls]
Statement introduced before Junos OS Release 7.4.
Specify properties for differentiated services in traffic engineering.
The statements are explained separately.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Routers for DiffServ-Aware Traffic Engineering on page 175
Copyright © 2011, Juniper Networks, Inc.
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disable
Syntax
Hierarchy Level
Release Information
Description
Default
Required Privilege
Level
Related
Documentation
disable;
[edit logical-systems logical-system-name protocols mpls],
[edit logical-systems logical-system-name protocols mpls interface interface-name],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
auto-bandwidth],
[edit protocols mpls],
[edit protocols mpls interface interface-name],
[edit protocols mpls label-switched-path lsp-name]
Statement introduced before Junos OS Release 7.4.
Disable the functionality of the configured object.
The configured object is enabled (operational) unless explicitly disabled.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Minimum MPLS Configuration on page 55
encoding-type
Syntax
Hierarchy Level
Release Information
Description
Default
Required Privilege
Level
Related
Documentation
262
encoding-type (ethernet | packet | pdh | sonet-sdh);
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
lsp-attributes],
[edit protocols mpls label-switched-path lsp-name lsp-attributes]
Statement introduced before Junos OS Release 7.4.
Specify the encoding type of payload carried by the LSP. It can be any of the following:
•
ethernet—Ethernet
•
packet—Packet
•
pdh—Plesiochronous digital hierarchy (PDH)
•
sonet-sdh—SONET/SDH
packet
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Encoding Type on page 558
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
exclude
See the following sections:
•
exclude (for Administrative Groups) on page 263
•
exclude (for Fast Reroute) on page 264
exclude (for Administrative Groups)
Syntax
Hierarchy Level
Release Information
Description
Options
Required Privilege
Level
Related
Documentation
exclude [ group-names ];
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
admin-group],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
(primary | secondary) path-name admin-group],
[edit protocols mpls label-switched-path lsp-name admin-group],
[edit protocols mpls label-switched-path lsp-name (primary | secondary) path-name
admin-group]
Statement introduced before Junos OS Release 7.4.
Define the administrative groups to exclude for an LSP or for a path’s primary and
secondary paths.
group-names—Names of one or more groups defined with the admin-groups statement.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Administrative Groups on page 153
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
exclude (for Fast Reroute)
Syntax
Hierarchy Level
Release Information
Description
Options
Required Privilege
Level
Related
Documentation
264
(exclude [ group-names ] | no-exclude);
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
fast-reroute],
[edit protocols mpls label-switched-path lsp-name fast-reroute]
Statement introduced before Junos OS Release 7.4.
Control exclusion of administrative groups:
•
exclude—Define the administrative groups to exclude for fast reroute.
•
no-exclude—Disable administrative group exclusion.
group-names—Names of one or more groups defined with the admin-groups statement.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Fast Reroute on page 134
•
admin-groups on page 244
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
exclude-srlg
Syntax
Hierarchy Level
Release Information
Description
exclude-srlg;
[edit protocols mpls],
[edit logical-systems logical-system-name protocols mpls],
[edit protocols mpls label-switched-path path-name],
[edit logical-systems logical-system-name protocols mpls label-switched-path path-name],
[edit protocols rsvp interface interface-name link-protection],
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection],
[edit protocols rsvp interface interface-name link-protection bypass destination],
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection bypass destination]
Statement introduced in Junos OS Release 11.4.
Exclude Shared Risk Link Group (SRLG) links for the secondary path for critical links
where it is imperative to keep the secondary and primary label-switched paths completely
disjoint from any common SRLG.
When specified, the Constrained Shortest Path First (CSPF) algorithm excludes any link
belonging to the set of SRLGs in the primary path. When not specified and if a link belongs
to the set of SRLGs in the primary path, CSPF adds the SRLG cost to the metric, but still
accepts the link for computing the path.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Example: Excluding SRLG Links Completely for the Secondary LSP on page 80
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
expand-loose-hop
Syntax
Hierarchy Level
Release Information
Description
expand-loose-hop;
[edit logical-systems logical-system-name protocols mpls],
[edit protocols mpls]
Statement introduced in Junos OS Release 7.6.
Point-to-multipoint LSP support introduced in Junos OS Release 11.2.
Allow an LSP to traverse multiple OSPF areas within a service provider’s network.
Allows a point-to-multipoint LSP to span multiple domains in a network. Effectively, this
allows you to configure one or more sub-LSPs (branches) in separate network domains.
Examples of such domains include OSPF areas and autonomous systems (ASs). A
sub-LSP of an inter-domain point-to-multipoint LSP can be intra-area, inter-area, or
inter-AS, depending on the location of the egress node (leaf) with respect to the ingress
node (source). Only OSPF areas are supported for inter-domain point-to-multipoint
LSPs. IS-IS levels are not supported.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Enabling Interarea Traffic Engineering on page 219
•
Configuring Inter-domain P2MP LSPs on page 209
explicit-null
Syntax
Hierarchy Level
Release Information
Description
Default
Required Privilege
Level
Related
Documentation
266
explicit-null;
[edit logical-systems logical-system-name protocols mpls],
[edit protocols mpls]
Statement introduced before Junos OS Release 7.4.
Advertise label 0 to the egress router of an LSP.
If you do not include the explicit-null statement in the MPLS configuration, label 3 (implicit
null) is advertised.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring RSVP to Pop the Label on the Ultimate-Hop Router on page 381
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
failure-action
Syntax
Hierarchy Level
Release Information
Description
Options
failure-action {
make-before-break teardown-timeout seconds;
teardown;
}
[edit logical-systems logical-system-name protocols mpls oam bfd-liveness-detection],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
oam bfd-liveness-detection],
[edit protocols mpls label-switched-path lsp-name oam bfd-liveness-detection],
[edit protocols mpls oam bfd-liveness-detection]
Statement introduced in Junos OS Release 9.4.
Configure route and next-hop properties in the event of a Bidirectional Forwarding
Detection (BFD) protocol session failure event on an RSVP label-switched path (LSP).
The failure event could be an existing BFD session that has gone down or a BFD session
that never came up. RSVP adds back the route or next hop when the relevant BFD session
comes back up.
make-before-break—When a BFD session fails for an RSVP LSP, an attempt is made to
signal a new LSP path before tearing down the old LSP path.
teardown—When a BFD session fails for an RSVP LSP, the associated LSP path is taken
down and resignaled immediately.
teardown-timeout seconds—When you configure the make-before-break option, you can
specify a time in seconds for the teardown-timeout option. At the end of the time
specified, the associated RSVP LSP is automatically torn down and resignaled.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring a Failure Action for the BFD Session on an RSVP LSP on page 235
Copyright © 2011, Juniper Networks, Inc.
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family mpls
Syntax
Hierarchy Level
Release Information
Description
Options
family mpls {
label-1;
label-2;
label-3;
no-labels;
no-label-1-exp;
payload {
ether-pseudowire;
ip {
layer-3-only;
port-data {
source-msb;
source-lsb;
destination-msb;
destination-lsb;
}
}
}
}
[edit forwarding-options hash-key]
Statement introduced before Junos OS Release 7.4.
no-label-1-exp option introduced in Junos OS Release 8.0.
label-3 and no-labels options introduced in Junos OS Release 8.1.
ether-pseudowire statement introduced in Junos OS Release 9.1 (M320 and T Series
routers only); support extended to M120 and MX Series routers in Junos OS Release 9.4.
For aggregated Ethernet and SONET/SDH interfaces only, configure load balancing
based on MPLS labels. Only the IPv4 protocol is supported.
label-1—Include only one label in the hash key.
label-2—Include both labels in the hash key.
label-3—Include the third MPLS label in the hash key.
no-labels—Include no MPLS labels in the hash key.
no-label-1-exp—Do not use the EXP bit of the first label in the hash calculation.
payload—Include bits from IP payload in the hash key.
ether-pseudowire (M120, M320, MX Series, and T Series routers)—Load-balance IPv4
traffic over Layer 2 Ethernet pseudowires.
ip—Include the IP address of the IPv4 or IPv6 payload in the hash key.
layer-3-only—Include only Layer 3 IP information.
port-data—Include the source and destination port field information.
268
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Chapter 10: Summary of MPLS Configuration Statements
source-msb—Include the most significant byte of the source port.
source-lsb—Include the least significant byte of the source port.
destination-msb—Include the most significant byte of the destination port.
destination-lsb—Include the least significant byte of the destination port.
Required Privilege
Level
Related
Documentation
interface—To view this statement in the configuration.
interface-control—To add this statement to the configuration.
•
Configuring Load Balancing Based on MPLS Labels on page 140
•
Configuring Load Balancing for Ethernet Pseudowires
fast-reroute
Syntax
Hierarchy Level
Release Information
Description
Options
Required Privilege
Level
Related
Documentation
fast-reroute {
(bandwidth bps | bandwidth-percent percentage);
(exclude [ group-names ] | no-exclude );
hop-limit number;
(include-all [ group-names ] | no-include-all);
(include-any [ group-names ] | no-include-any);
}
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name]
Statement introduced before Junos OS Release 7.4.
Establish detours for the LSP so that if a node or link in the LSP fails, the traffic on the
LSP can be rerouted with minimal packet loss.
The statements are explained separately.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Fast Reroute on page 134
Copyright © 2011, Juniper Networks, Inc.
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fate-sharing
Syntax
Hierarchy Level
Release Information
Description
Options
fate-sharing {
group group-name {
cost value;
from address <to address>;
}
}
[edit logical-systems logical-system-name routing-options],
[edit logical-systems logical-system-name routing-instances routing-instance-name
routing-options],
[edit routing-options],
[edit routing-instances routing-instance-name routing-options]
Statement introduced before Junos OS Release 7.4.
Statement introduced in Junos OS Release 11.3 for the QFX Series.
Specify groups of objects that share characteristics resulting in backup paths to be used
if primary paths fail. All objects are treated as /32 host addresses. You specify one or
more objects within a group. The objects can be LAN interfaces, router IDs, or
point-to-point links. The sequence is insignificant.
cost value—Cost assigned to the group.
Range: 1 through 65,535
Default: 1
from address—Address of the router or address of the LAN/NBMA interface. For example,
an Ethernet network with four hosts in the same fate-sharing group would require
you to list all four of the separate from addresses in the group.
group group-name—Each fate-sharing group must have a name, which can have a
maximum of 32 characters, including letters, numbers, periods (.), and hyphens (-).
You can define up to 512 groups.
to address—(Optional) Address of egress router. For point-to-point link objects, you must
specify both a from and a to address.
Required Privilege
Level
Related
Documentation
270
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Alternate Backup Paths Using Fate Sharing on page 58
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
from
Syntax
Hierarchy Level
Release Information
Description
from address;
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name]
Statement introduced before Junos OS Release 7.4.
Specify the source address to use for the LSP.
The address you specify does not affect the outgoing interface used by the LSP.
Default
Options
Required Privilege
Level
Related
Documentation
If you do not include this statement, the software automatically selects the loopback
interface as the address.
address—IP address.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Ingress Router Address for LSPs on page 129
Copyright © 2011, Juniper Networks, Inc.
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gpid
Syntax
Hierarchy Level
Release Information
Description
gpid (ethernet | hdlc | ipv4 | pos-scrambling-crc-16 | pos-no-scrambling-crc-16 |
pos-scrambling-crc-32 | pos-no-scrambling-crc-32 | ppp);
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
lsp-attributes],
[edit protocols mpls label-switched-path lsp-name lsp-attributes]
Statement introduced before Junos OS Release 7.4.
pos-scrambling-crc-16, pos-no-scrambling-crc-16, pos-scrambling-crc-32, and
pos-no-scrambling-crc-32 options added in Junos OS Release 8.0.
Specify the type of payload carried by the LSP. It can be any of the following:
•
ethernet—Ethernet (GPID value: 33)
•
hdlc—High-level Data Link Control (HDLC) (GPID value: 44)
•
ipv4—IP version 4 (GPID value: 0x0800)
•
pos-no-scrambling-crc-16—for interoperability with other vendors’ equipment (GPID
value: 29)
•
pos-no-scrambling-crc-32—for interoperability with other vendors’ equipment (GPID
value: 30)
•
pos-scrambling-crc-16—for interoperability with other vendors’ equipment (GPID value:
31)
•
pos-scrambling-crc-32—for interoperability with other vendors’ equipment (GPID value:
32)
•
Default
Required Privilege
Level
Related
Documentation
272
ppp—Point-to-Point Protocol (PPP) (GPID value: 50)
ipv4
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the GPID on page 558
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
hop-limit
Syntax
Hierarchy Level
Release Information
Description
hop-limit number;
[edit logical-systems logical-system-name protocols mpls],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
fast-reroute],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
(primary | secondary) path-name],
[edit protocols mpls],
[edit protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name fast-reroute],
[edit protocols mpls label-switched-path lsp-name (primary | secondary) path-name]
Statement introduced before Junos OS Release 7.4.
For an LSP, specify the maximum number of routers that the LSP can traverse, including
the ingress and egress routers.
For fast reroute, how many more routers a detour is allowed to traverse compared with
the LSP itself. For example, if an LSP traverses 4 routers, any detour for the LSP can be
no more than 10 router hops, including the ingress and egress routers.
Options
number—Maximum number of hops.
Range: 2 through 255 (for an LSP); 0 through 255 (for fast reroute)
Default: 255 (for an LSP); 6 (for fast reroute)
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Fast Reroute on page 134
•
Limiting the Number of Hops in LSPs on page 166
Copyright © 2011, Juniper Networks, Inc.
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icmp-tunneling
Syntax
Hierarchy Level
Release Information
Description
Required Privilege
Level
Related
Documentation
274
icmp-tunneling;
[edit logical-systems logical-system-name protocols mpls],
[edit protocols mpls]
Statement introduced before Junos OS Release 7.4.
Enable ICMP tunneling, which can be used for debugging and tracing purposes.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring ICMP Message Tunneling for MPLS on page 71
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
include-all
See the following sections:
•
include-all (for Administrative Groups) on page 275
•
include-all (for Fast Reroute) on page 276
include-all (for Administrative Groups)
Syntax
Hierarchy Level
Release Information
Description
Options
Required Privilege
Level
Related
Documentation
include-all [ group-names ];
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
admin-group],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
(primary | secondary) path-name admin-group],
[edit protocols mpls label-switched-path lsp-name admin-group],
[edit protocols mpls label-switched-path lsp-name (primary | secondary) path-name
admin-group]
Statement introduced before Junos OS Release 7.4.
Require the LSP to traverse links that include all of the defined administrative groups.
group-names—One or more names of groups defined with the admin-groups statement.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Administrative Groups on page 153
•
admin-groups on page 244
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Junos OS 11.4 MPLS Applications Configuration Guide
include-all (for Fast Reroute)
Syntax
Hierarchy Level
Release Information
Description
Options
Required Privilege
Level
Related
Documentation
276
(include-all [ group-names ] | no-include-all);
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
fast-reroute],
[edit protocols mpls label-switched-path lsp-name fast-reroute]
Statement introduced before Junos OS Release 7.4.
Control inclusion of administrative groups:
•
include-all—Define the administrative groups that must all be included for fast reroute.
•
no-include-all—Disable administrative group inclusion.
group-names—One or more names of groups defined with the admin-groups statement.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Fast Reroute on page 134
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
include-any
See the following sections:
•
include-any (for Administrative Groups) on page 277
•
include-any (for Fast Reroute) on page 278
include-any (for Administrative Groups)
Syntax
Hierarchy Level
Release Information
Description
Options
Required Privilege
Level
Related
Documentation
include-any [ group-names ];
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
admin-group],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
(primary | secondary) path-name admin-group],
[edit protocols mpls label-switched-path lsp-name admin-group],
[edit protocols mpls label-switched-path lsp-name (primary | secondary) path-name
admin-group]
Statement introduced before Junos OS Release 7.4.
Define the administrative groups to include for an LSP or for a path’s primary and
secondary paths.
group-names—One or more names of groups defined with the admin-groups statement.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Administrative Groups on page 153
Copyright © 2011, Juniper Networks, Inc.
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include-any (for Fast Reroute)
Syntax
Hierarchy Level
Release Information
Description
Options
Required Privilege
Level
Related
Documentation
278
(include-any [ group-names ] | no-include-any);
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
fast-reroute],
[edit protocols mpls label-switched-path lsp-name fast-reroute]
Statement introduced before Junos OS Release 7.4.
Control inclusion of administrative groups:
•
include-any—Define the administrative groups to include for fast reroute.
•
no-include-any—Disable administrative group inclusion.
group-names—One or more names of groups defined with the admin-groups statement.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Fast Reroute on page 134
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
ingress
Syntax
Hierarchy Level
Release Information
Description
ingress {
bandwidth bps;
class-of-service cos-value;
description string;
install {
destination-prefix <active>;
}
link-protection bypass-name name;
metric metric;
next-hop (address | interface-name | address/interface-name);
node-protection bypass-name name next-next-label label;
no-install-to-address;
policing {
filter filter-name;
no-auto-policing;
}
preference preference;
push out-label;
to address;
}
[edit logical-systems logical-system-name protocols mpls static-label-switched-path
lsp-name],
[edit protocols mpls static-label-switched-path lsp-name]
Statement introduced in Junos OS Release 10.1.
Configure an ingress LSR for a static LSP.
The remaining statements are explained separately
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Static LSPs on page 193
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Junos OS 11.4 MPLS Applications Configuration Guide
install
Syntax
Hierarchy Level
Release Information
Description
Options
install {
destination-prefix <active>;
}
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit logical-systems logical-system-name protocols mpls static-label-switched-path
lsp-name ingress],
[edit protocols mpls label-switched-path lsp-name],
[edit protocols mpls static-label-switched-path lsp-name ingress]
Statement introduced before Junos OS Release 7.4.
Associate one or more prefixes with an LSP. When the LSP is up, all the prefixes are
installed as entries into the inet.3 routing table.
active—(Optional) Install the route into the inet.0 routing table. This allows you to issue
a ping or traceroute command on this address.
destination-prefix—Address to associate with the LSP.
Required Privilege
Level
Related
Documentation
280
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Adding LSP-Related Routes to the inet.3 Routing Table on page 136
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
interface
Syntax
Hierarchy Level
Release Information
Description
Options
interface (interface-name | all) {
disable;
admin-group [ group-names ];
srlg srlg-name;
}
[edit logical-systems logical-system-name protocols mpls],
[edit protocols mpls]
Statement introduced before Junos OS Release 7.4.
Enable MPLS on one or more interfaces.
interface-name—Name of the interface on which to configure MPLS. To configure all
interfaces, specify all. For details about specifying interfaces, see the Junos OS Network
Interfaces Configuration Guide.
srlg srlg-name—Name of the SRLG to associate with an interface.
The remaining options are explained separately.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Intermediate (Transit) and Egress Routers for Static LSPs on page 196
•
Example: Configuring SRLG on page 71
ipv6-tunneling
Syntax
Hierarchy Level
Release Information
Description
Required Privilege
Level
Related
Documentation
ipv6-tunneling;
[edit logical-systems logical-system-name protocols mpls],
[edit protocols mpls]
Statement introduced before Junos OS Release 7.4.
Allow IPv6 routes to be resolved over an MPLS network by converting all routes stored
in the inet.3 routing table to IPv4-mapped IPv6 addresses and then copying them into
the inet6.3 routing table. This routing table can be used to resolve next hops for both
inet6 and inet6-vpn routes.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Enabling IPv6 Tunneling on PE Routers on page 70
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label-switched-path
Syntax
282
label-switched-path lsp-name {
disable;
adaptive;
admin-down;
admin-group {
exclude [ group-names ];
include-all [ group-names ];
include-any [ group-names ];
}
auto-bandwidth {
adjust-interval seconds;
adjust-threshold percentage;
maximum-bandwidth bps;
minimum-bandwidth bps;
monitor-bandwidth;
}
bandwidth bps {
ct0 bps;
ct1 bps;
ct2 bps;
ct3 bps;
}
class-of-service cos-value;
description text;
fast-reroute {
(bandwidth bps | bandwidth-percent percentage);
(exclude [ group-names ] | no-exclude);
hop-limit number;
(include-all [ group-names ] | no-include-all);
(include-any [ group-names ] | no-include-any);
}
from address;
install {
destination-prefix/prefix-length <active>;
}
ldp-tunneling;
link-protection;
lsp-attributes {
encoding-type (ethernet | packet | pdh | sonet-sdh);
gpid (ethernet | hdlc | ipv4 | pos-scrambling-crc-16 | pos-no-scrambling-crc-16 |
pos-scrambling-crc-32 | pos-no-scrambling-crc-32 | ppp);
signal-bandwidth type;
switching-type (fiber | lambda | psc-1 | tdm);
}
metric metric;
no-cspf;
no-decrement-ttl;
node-link-protection;
optimize-timer seconds;
p2mp lsp-name;
policing {
filter filter-name;
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
no-auto-policing;
}
preference preference;
primary path-name {
adaptive;
admin-group {
exclude [ group-names ];
include-all [ group-names ];
include-any [ group-names ];
}
bandwidth bps {
ct0 bps;
ct1 bps;
ct2 bps;
ct3 bps;
}
class-of-service cos-value;
hop-limit number;
no-cspf;
no-decrement-ttl;
optimize-timer seconds;
preference preference;
priority setup-priority reservation-priority;
(record | no-record);
select (manual | unconditional);
standby;
}
priority setup-priority reservation-priority;
(random | least-fill | most-fill);
(record | no-record);
retry-limit number;
retry-timer seconds;
revert-timer seconds;
secondary path-name {
adaptive;
admin-group {
exclude[ group-names ];
include-all [ group-names ];
include-any [ group-names ];
}
bandwidth bps {
ct0 bps;
ct1 bps;
ct2 bps;
ct3 bps;
}
class-of-service cos-value;
hop-limit number;
no-cspf;
no-decrement-ttl;
optimize-timer seconds;
preference preference;
priority setup-priority reservation-priority;
(record | no-record);
select (manual | unconditional);
standby;
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}
soft-preemption;
standby;
to address;
traceoptions {
file filename <files number> <size size> <world-readable | no-world-readable>;
flag flag <flag-modifier> <disable>;
}
}
Hierarchy Level
Release Information
Description
Options
[edit logical-systems logical-system-name protocols mpls],
[edit protocols mpls]
Statement introduced before Junos OS Release 7.4.
Configure an LSP to use in dynamic MPLS. When configuring an LSP, you must specify
the address of the egress router in the to statement. All remaining statements are optional.
lsp-name—Name that identifies the LSP. The name can be up to 32 characters and can
contain letters, digits, periods, and hyphens. To include other characters, enclose
the name in quotation marks. The name must be unique within the ingress router.
The remaining statements are explained separately.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Minimum MPLS Configuration on page 55
ldp-tunneling
Syntax
Hierarchy Level
Release Information
Description
Required Privilege
Level
Related
Documentation
ldp-tunneling;
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name]
Statement introduced before Junos OS Release 7.4.
Enable the LSP to be used for LDP tunneling.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Enabling LDP over RSVP-Established LSPs on page 459
least-fill
See
284
random
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
link-protection
See the following sections:
•
link-protection (Dynamic LSPs) on page 285
•
link-protection (Static LSPs) on page 286
link-protection (Dynamic LSPs)
Syntax
Hierarchy Level
Release Information
Description
link-protection;
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name]
Statement introduced before Junos OS Release 7.4.
Enable link protection on the specified LSP, which helps to ensure that traffic sent over
a specific interface to a neighboring router can continue to reach the router if that interface
fails. For point-to-multipoint LSPs, including this statement extends link protection to
all of the paths used by the LSP.
To fully enable link protection, you must also include the link-protection statement at
the [edit protocols rsvp interface interface-name] or [edit
logical-systems logical-system-name protocols rsvp interface interface-name] hierarchy
level.
Default
Required Privilege
Level
Related
Documentation
Link protection is disabled.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Link Protection for Point-to-Multipoint LSPs on page 205
•
Configuring Node Protection or Link Protection for LSPs on page 364
•
link-protection (RSVP) on page 401
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
link-protection (Static LSPs)
Syntax
Hierarchy Level
Release Information
Description
Default
Options
Required Privilege
Level
Related
Documentation
286
link-protection bypass-name name;
[edit logical-systems logical-system-name protocols mpls
static-label-switched-path lsp-name ingress],
[edit logical-systems logical-system-name protocols mpls
static-label-switched-path lsp-name transit incoming-label],
[edit protocols mpls static-label-switched-path lsp-name ingress],
[edit protocols mpls static-label-switched-path lsp-name transit incoming-label]
Statement introduced in Junos OS Release 10.1.
Enable link protection on the specified static LSP. Link protection helps to ensure that
traffic sent over a specific interface to a neighboring router can continue to reach the
router if that interface fails.
Link protection is disabled.
bypass-name name—Bypass LSP name.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Static LSPs on page 193
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
log-updown
Syntax
Hierarchy Level
Release Information
Description
Default
Options
log-updown {
no-trap {
mpls-lsp-traps;
rfc3812-traps;
}
(syslog | no-syslog);
trap;
trap-path-down;
trap-path-up;
}
[edit logical-systems logical-system-name protocols mpls],
[edit protocols mpls]
Statement introduced before Junos OS Release 7.4.
The mpls-lsp-traps and rfc-3812-traps options added in Junos OS Release 9.0.
Log a message or send an SNMP trap whenever an LSP makes a transition from up to
down, or vice versa, and whenever an LSP switches from one active path to another. Only
the ingress router performs these operations.
There is no default behavior for this statement. If you do not specify the options, the
configuration cannot be committed.
no-syslog—Do not log a message to the system log file.
no-trap—Do not send an SNMP trap.
syslog—Log a message to the system log file.
trap—Send an SNMP trap.
trap-path-down—Send an SNMP trap when an LSP path goes down.
trap-path-up—Send an SNMP trap when an LSP path comes up.
The no-trap statement is explained separately.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring System Log Messages and SNMP Traps for LSPs on page 223
•
Junos OS Network Management Configuration Guide
•
no-trap on page 298
•
traceoptions on page 332
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
lsp-attributes
Syntax
Hierarchy Level
Release Information
Description
lsp-attributes {
encoding-type (ethernet | packet | pdh | sonet-sdh);
gpid (ethernet | hdlc | ipv4 | pos-scrambling-crc-16 | pos-no-scrambling-crc-16 |
pos-scrambling-crc-32 | pos-no-scrambling-crc-32 | ppp);
signal-bandwidth type;
switching-type (fiber | lambda | psc-1 | tdm);
}
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name]
Statement introduced before Junos OS Release 7.4.
pos-scrambling-crc-16, pos-no-scrambling-crc-16, pos-scrambling-crc-32, and
pos-no-scrambling-crc-32 options added in Junos OS Release 8.0.
Define the parameters signaled during LSP setup. These usually determine the nature
of the resource (label) allocated for the LSP.
The options are explained separately.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring MPLS LSPs for GMPLS on page 557
maximum-bandwidth
Syntax
Hierarchy Level
Release Information
Description
Options
Required Privilege
Level
Related
Documentation
288
maximum-bandwidth bps;
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
auto-bandwidth],
[edit protocols mpls label-switched-path lsp-name auto-bandwidth]
Statement introduced before Junos OS Release 7.4.
Specify the maximum amount of bandwidth in bits per second (bps).
bps—Maximum amount of bandwidth.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Maximum and Minimum Bounds of the LSP’s Bandwidth on page 148
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
maximum-labels
Syntax
Hierarchy Level
Release Information
Description
Options
maximum-labels maximum-labels;
[edit logical-systems logical-system-name interfaces interface-name unit logical-unit-number
family mpls],
[edit interfaces interface-name unit logical-unit-number family mpls]
Statement introduced in Junos OS Release 10.1.
On the logical interface, specify the maximum number of MPLS labels upon which MPLS
can operate.
maximum-labels—Maximum number of labels.
Range: 3 through 5
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Maximum Number of MPLS Labels on page 213
•
Junos VPNs Configuration Guide
metric
Syntax
Hierarchy Level
Release Information
Description
Options
metric metric;
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit logical-systems logical-system-name protocols mpls
static-label-switched-path lsp-name ingress],
[edit protocols mpls label-switched-path lsp-name],
[edit protocols mpls static-label-switched-path lsp-name ingress]
Statement introduced before Junos OS Release 7.4.
Compare against another LSP or against an IGP route. To disable dynamic metric tracking,
assign a fixed metric value to an LSP. If no metric is assigned, the LSP metric is dynamic
and automatically tracks underlying IGP metrics.
metric—LSP metric value.
Default: No metric assigned (dynamic)
Range: 1 through 16,777,215
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Static LSP Metrics on page 138
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
minimum-bandwidth
Syntax
Hierarchy Level
Release Information
Description
Options
Required Privilege
Level
Related
Documentation
minimum-bandwidth bps;
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
auto-bandwidth],
[edit protocols mpls label-switched-path lsp-name auto-bandwidth]
Statement introduced before Junos OS Release 7.4.
Set the minimum bandwidth in bps for an LSP with automatic bandwidth allocation
enabled.
bps—Miniminum bandwidth for the LSP.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Maximum and Minimum Bounds of the LSP’s Bandwidth on page 148
monitor-bandwidth
Syntax
Hierarchy Level
Release Information
Description
Required Privilege
Level
Related
Documentation
monitor-bandwidth;
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
auto-bandwidth],
[edit protocols mpls label-switched-path lsp-name auto-bandwidth]
Statement introduced before Junos OS Release 7.4.
Do not automatically adjust bandwidth allocation. However, the maximum average
bandwidth utilization is monitored on the LSP, and the information is recorded in the
MPLS statistics file.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Passive Bandwidth Utilization Monitoring on page 151
most-fill
See
290
random
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
mpls
Syntax
Hierarchy Level
Release Information
Description
Required Privilege
Level
Related
Documentation
mpls { ... }
[edit logical-systems logical-system-name protocols],
[edit protocols]
Statement introduced before Junos OS Release 7.4.
Enable MPLS on the router.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Minimum MPLS Configuration on page 55
mtu-signaling
Syntax
Hierarchy Level
Release Information
Description
Required Privilege
Level
Related
Documentation
mtu-signaling;
[edit logical-systems logical-system-name protocols mpls path-mtu rsvp],
[edit protocols mpls path-mtu rsvp]
Statement introduced before Junos OS Release 7.4.
Enable MTU signaling in RSVP.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Enabling MTU Signaling in RSVP on page 380
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
next-hop
Syntax
Hierarchy Level
Release Information
Description
Options
next-hop (address | interface-name | address/interface-name);
[edit logical-systems logical-system-name protocols mpls
static-label-switched-path lsp-name bypass],
[edit logical-systems logical-system-name protocols mpls
static-label-switched-path lsp-name ingress],
[edit logical-systems logical-system-name protocols mpls
static-label-switched-path lsp-name transit incoming-label],
[edit protocols mpls static-label-switched-path lsp-name bypass],
[edit protocols mpls static-label-switched-path lsp-name ingress],
[edit protocols mpls static-label-switched-path lsp-name transit incoming-label]
Statement introduced before Junos OS Release 7.4.
IP address of the next hop to the destination, specified as the IP address of the next hop,
the interface name (for point-to-point interfaces only), or the address/interface-name to
specify an IP address on an operational interface.
address—IP address of the next-hop router.
interface-name—IP address of the outgoing interface. It must be a point-to-point interface.
The name can be a simple or fully qualified domain name.
Required Privilege
Level
Related
Documentation
292
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Ingress Router for Static LSPs on page 193
•
Configuring the Intermediate (Transit) and Egress Routers for Static LSPs on page 196
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
no-cspf
Syntax
Hierarchy Level
Release Information
Description
no-cspf;
[edit logical-systems logical-system-name protocols mpls],
[edit logical-systems logical-system-name protocols mplslabel-switched-path lsp-name],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
(primary | secondary) path-name],
[edit protocols mpls],
[edit protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name (primary | secondary) path-name]
Statement introduced before Junos OS Release 7.4.
Disable constrained-path LSP computation.
An explicit-path LSP is completely configured through operator action. Once configured,
it is initiated only along the explicitly specified path.
A constrained-path LSP relies on an ingress router to compute the complete path. The
ingress router takes into account the following information during the computation:
•
Interior gateway protocol (IGP) topology database
•
Link utilization information from extensions in the IGP link-state database
•
Administrative group information from extensions in the IGP link-state database
•
LSP requirements, including bandwidth, hop count, and administrative group
Constrained-path LSPs can generally avoid link failures and congested links. They also
permit recomputation (therefore, a new path) during topology changes or unsuccessful
setup.
Default
Required Privilege
Level
Related
Documentation
Constrained-path LSP computation enabled.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Disabling Constrained-Path LSP Computation on page 152
•
Configuring Explicit-Path LSPs on page 200
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
no-decrement-ttl
Syntax
Hierarchy Level
Release Information
no-decrement-ttl;
[edit logical-systems logical-system-name protocols mpls],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
(primary | secondary) path-name],
[edit protocols mpls],
[edit protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name (primary | secondary) path-name]
Statement introduced before Junos OS Release 7.4.
Description
Disable normal time-to-live (TTL) decrementing, which decrements the TTL field in the
IP header by 1. This statement decrements the IP TTL by 1 before encapsulating the IP
packet within an MPLS packet. When the penultimate router pops off the top label, it
does not use the standard write-back procedure of writing the MPLS TTL into the IP TTL
field. Therefore, the IP packet is decremented by 1. The ultimate router then decrements
the packet by one more for a total cloud appearance of 2, thus hiding the network
topology.
Default
Normal TTL decrementing enabled; the TTL field value is decremented by 1 as the packet
passes through each label-switched router in the LSP.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Disabling Normal TTL Decrementing on page 143
•
no-propagate-ttl on page 297
no-exclude
See
exclude (for Fast Reroute)
See
include-all (for Fast Reroute)
no-include-all
no-include-any
See
294
include-any (for Fast Reroute)
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
no-mcast-replication
Syntax
Hierarchy Level
Release Information
Description
Default
Required Privilege
Level
Related
Documentation
no-mcast-replication;
[edit chassis fpc slot-number pic pic-number],
[edit chassis lcc number fpc slot-number pic pic-number]
Statement introduced in Junos OS Release 11.3.
For point-to-multipoint LSPs configured on T Series routers, protect the Packet Forwarding
Engine (PFE) from bandwidth saturation. When a PFE does not need to replicate traffic,
the PFE’s bandwidth is less likely to become saturated. When you include the
no-mcast-replication statement, the PFE is forced to be a leaf node in the binary tree.
Leaf nodes, unlike branch nodes, do not replicate traffic in the process of forwarding
traffic. Because leaf nodes have no children, they do not need to replicate traffic, and
thus are less likely to become saturated with traffic.
If you omit the no-mcast-replication statement, the PFE can become a branch node or
a leaf node. When the PFE becomes a branch node, the PFE must replicate traffic.
interface—To view this statement in the configuration.
interface-control—To add this statement to the configuration.
•
Point-to-Multipoint LSPs Overview on page 52
no-install-to-address
Syntax
Hierarchy Level
Release Information
no-install-to-address;
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit logical-systems logical-system-name protocols mpls
static-label-switched-path lsp-name ingress],
[edit protocols mpls label-switched-path lsp-name],
[edit protocols mpls static-label-switched-path lsp-name ingress]
Statement introduced in Junos OS Release 7.4.
Description
Prevent the egress router address configured using the to statement from being installed
into the inet.3 and inet.0 routing tables.
Default
The egress router address for an LSP is installed into the inet.3 and inet.0 routing tables.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Preventing the Addition of Egress Router Addresses to Routing Tables on page 130
•
to on page 331
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
node-protection (Static LSP)
Syntax
Hierarchy Level
Release Information
Description
Default
Options
node-protection bypass-name name next-next-label label;
[edit logical-systems logical-system-name protocols mpls
static-label-switched-path lsp-name ingress],
[edit logical-systems logical-system-name protocols mpls
static-label-switched-path lsp-name transit incoming-label],
[edit protocols mpls static-label-switched-path lsp-name ingress],
[edit protocols mpls static-label-switched-path lsp-name transit incoming-label]
Statement introduced in JUNOS Release 10.1.
Enable node protection on the specified static bypass LSP. Node protection ensures that
traffic from an LSP traversing a neighboring router can continue to reach its destination
even if the neighboring router fails.
Node protection is disabled.
bypass-name name—Bypass LSP name.
next-next-label label—Bypass LSP name.
Required Privilege
Level
Related
Documentation
296
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Static LSPs on page 193
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
no-propagate-ttl
Syntax
Hierarchy Level
Release Information
no-propagate-ttl;
[edit logical-systems logical-system-name protocols mpls],
[edit protocols mpls]
Statement introduced before Junos OS Release 7.4.
Description
Disable normal time-to-live (TTL) decrementing. You configure this statement once per
router, and it affects all RSVP-signaled or LDP-signaled LSPs. When this router acts as
an ingress router for an LSP, it pushes an MPLS header with a TTL value of 255, regardless
of the IP packet TTL. When the router acts as the penultimate router, it pops the MPLS
header without writing the MPLS TTL into the IP packet.
Default
Normal TTL decrementing enabled; the TTL field value is decremented by 1 as the packet
passes through each label-switched router in the LSP.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Disabling Normal TTL Decrementing on page 143
•
Example: Disabling Normal TTL Decrementing in a VRF Routing Instance (on Layer 3
VPNs or in the Junos VPNs Configuration Guide)
•
no-decrement-ttl on page 294
no-record
See
record
Copyright © 2011, Juniper Networks, Inc.
297
Junos OS 11.4 MPLS Applications Configuration Guide
no-trap
Syntax
Hierarchy Level
Release Information
Description
Options
no-trap {
mpls-lsp-traps;
rfc-3812-traps;
}
[edit logical-systems logical-system-name protocols mpls log-updown],
[edit protocols mpls log-updown]
Statement introduced before Junos OS Release 7.4.
The mpls-lsp-traps and rfc-3812-traps options added in Junos OS Release 9.0.
Prevent the transmission of SNMP traps.
mpls-lsp-traps—Block the MPLS LSP traps defined in the jnx-mpls.mib, but allows the
rfc3812.mib traps.
rfc-3812-traps—Block the traps defined in the rfc3812.mib, but allows the MPLS LSP traps
defined in the jnx-mpls.mib.
Required Privilege
Level
Related
Documentation
298
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring System Log Messages and SNMP Traps for LSPs on page 223
•
Junos OS Network Management Configuration Guide
•
traceoptions on page 332
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
node-protection (Static LSP)
Syntax
Hierarchy Level
Release Information
Description
Default
Options
node-protection bypass-name name next-next-label label;
[edit logical-systems logical-system-name protocols mpls
static-label-switched-path lsp-name ingress],
[edit logical-systems logical-system-name protocols mpls
static-label-switched-path lsp-name transit incoming-label],
[edit protocols mpls static-label-switched-path lsp-name ingress],
[edit protocols mpls static-label-switched-path lsp-name transit incoming-label]
Statement introduced in JUNOS Release 10.1.
Enable node protection on the specified static bypass LSP. Node protection ensures that
traffic from an LSP traversing a neighboring router can continue to reach its destination
even if the neighboring router fails.
Node protection is disabled.
bypass-name name—Bypass LSP name.
next-next-label label—Bypass LSP name.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Static LSPs on page 193
Copyright © 2011, Juniper Networks, Inc.
299
Junos OS 11.4 MPLS Applications Configuration Guide
oam
Syntax
Hierarchy Level
Release Information
Description
Options
oam {
bfd-liveness-detection{
failure-action teardown;
minimum-interval milliseconds;
minimum-receive-interval milliseconds;
minimum-transmit-interval milliseconds;
multiplier detection-time-multiplier;
}
lsp-ping-interval seconds;
}
[edit protocols mpls],
[edit protocols mpls label-switched-path lsp-name]
[edit protocols mpls label-switched-path lsp-name primary path-name]
Statement introduced in Junos OS Release 7.6.
lsp-ping-interval option introduced in Junos OS Release 9.4.
Enable Operation, Administration, and Maintenance (OAM) for RSVP-signaled LSPs.
lsp-ping-interval seconds—Specify the duration of the LSP ping interval in seconds. To
issue a ping on an RSVP-signaled LSP, use the ping mpls rsvp command.
The remaining statements are explained separately.
Required Privilege
Level
Related
Documentation
300
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring BFD for MPLS IPv4 LSPs on page 233
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
optimize-aggressive
Syntax
Hierarchy Level
Release Information
Description
Default
Required Privilege
Level
Related
Documentation
optimize-aggressive;
[edit logical-systems logical-system-name protocols mpls],
[edit protocols mpls]
Statement introduced before Junos OS Release 7.4.
If enabled, the LSP reoptimization is based solely on the IGP metric. The reoptimization
process ignores the available bandwidth ratio calculations, the least-fill 10 percent
congestion improvement rule, and the hop-counts rule. This statement makes
reoptimization more aggressive than the default.
Aggressive optimization is disabled.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Optimizing Signaled LSPs on page 161
Copyright © 2011, Juniper Networks, Inc.
301
Junos OS 11.4 MPLS Applications Configuration Guide
optimize-timer
Syntax
Hierarchy Level
Release Information
Description
optimize-timer seconds;
[edit logical-systems logical-system-name protocols mpls],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
(primary | secondary) path-name],
[edit protocols mpls],
[edit protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name (primary | secondary) path-name]
Statement introduced before Junos OS Release 7.4.
Enable periodic reoptimization of an LSP that is already set up. If topology changes occur,
an existing path might become suboptimal, and a subsequent recomputation might be
able to determine a better path. This option is useful only on LSPs for which
constrained-path computation is enabled; that is, for which the no-cspf statement is not
configured.
To avoid extensive resource consumption that might result because of frequent path
recomputations, or to avoid destabilizing the network as a result of constantly changing
LSPs, we recommend that you either leave the timer value sufficiently large or disable
the timer value.
Default
Options
The optimize timer is disabled.
seconds—Length of the optimize timer, in seconds.
Range: 0 through 65,535 seconds
Default: 0 seconds (the optimize timer is disabled)
Required Privilege
Level
Related
Documentation
302
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Optimizing Signaled LSPs on page 161
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
p2mp
Syntax
Hierarchy Level
Release Information
Description
Options
p2mp p2mp-lsp-name;
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name]
Statement introduced before Junos OS Release 7.4.
Specify an LSP as either a point-to-multipoint LSP or as a branch LSP of a
point-to-multipoint LSP by specifying the point-to-multipoint LSP path name.
p2mp-lsp-name—Name of the point-to-multipoint LSP path that identifies the sequence
of nodes that form the point-to-multipoint LSP. The name can contain up to 32
characters and can include letters, digits, periods, and hyphens. To include other
characters or use a longer name, enclose the name in quotation marks. The name
must be unique within the ingress router.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Primary Point-to-Multipoint LSP on page 204
p2mp-lsp-next-hop
Syntax
Hierarchy Level
Release Information
Description
Options
Required Privilege
Level
Related
Documentation
p2mp-lsp-next-hop point-to-multipoint-lsp-next-hop;
[edit logical-systems logical-system-name routing-options static route route-name],
[edit routing-options static route route-name]
Statement introduced before Junos OS Release 7.4.
Specify the name of the point-to-multipoint LSP to be used as a next hop for the static
route.
point-to-multipoint-lsp-next-hop—Name of the point-to-multipoint LSP.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Static Unicast Routes for Point-to-Multipoint LSPs on page 199
Copyright © 2011, Juniper Networks, Inc.
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path
Syntax
Hierarchy Level
Release Information
Description
path path-name {
(address | hostname) <strict | loose>;
}
[edit logical-systems logical-system-name protocols mpls],
[edit protocols mpls]
Statement introduced before Junos OS Release 7.4.
Create a named path and optionally specify the sequence of explicit routers that form
the path.
You must include this statement when configuring explicit LSPs.
Options
address—IP address of each transit router in the LSP. You must specify the address or
hostname of each transit router, although you do not need to list each transit router
if its type is loose. As an option, you can include the ingress and egress routers in the
path. Specify the addresses in order, starting with the ingress router (optional) or
the first transit router, and continuing sequentially along the path until reaching the
egress router (optional) or the router immediately before the egress router.
Default: If you do not specify any routers explicitly, no routing limitations are imposed
on the LSP.
hostname—See address.
Default: If you do not specify any routers explicitly, no routing limitations are imposed
on the LSP.
loose—(Optional) Indicate that the next address in the path statement is a loose link.
This means that the LSP can traverse through other routers before reaching this
router.
Default: strict
path-name—Name that identifies the sequence of nodes that form an LSP. The name
can contain up to 32 characters and can include letters, digits, periods, and hyphens.
To include other characters or use a longer name, enclose the name in quotation
marks. The name must be unique within the ingress router.
strict—(Optional) Indicate that the LSP must go to the next address specified in the path
statement without traversing other nodes. This is the default.
Required Privilege
Level
Related
Documentation
304
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Creating Named Paths on page 56
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
path-mtu
Syntax
Hierarchy Level
Release Information
Description
path-mtu {
allow-fragmentation;
rsvp {
mtu-signaling;
}
}
[edit logical-systems logical-system-name protocols mpls],
[edit protocols mpls]
Statement introduced before Junos OS Release 7.4.
Configure MTU options for MPLS paths, including packet fragmentation and MTU
signaling.
The remaining statements are explained separately.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring MTU Signaling in RSVP on page 380
policing
Syntax
Hierarchy Level
Release Information
Description
Options
policing {
filter filter-name;
no-auto-policing;
}
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit logical-systems logical-system-name protocols mpls
static-label-switched-path lsp-name ingress],
[edit protocols mpls label-switched-path lsp-name],
[edit protocols mpls static-label-switched-path lsp-name ingress]
Statement introduced before Junos OS Release 7.4.
Specify the policing filter for the LSP.
filter filter-name—Specify the name of the policing filter.
no-auto-policing—Disable automatic policing on this LSP.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Policers for LSPs on page 226
•
auto-policing on page 251
Copyright © 2011, Juniper Networks, Inc.
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pop
Syntax
Hierarchy Level
Release Information
Description
Required Privilege
Level
Related
Documentation
306
pop;
[edit logical-systems logical-system-name protocols mpls
static-label-switched-path lsp-name transit incoming-label],
[edit protocols mpls static-label-switched-path lsp-name transit incoming-label]
Statement introduced before Junos OS Release 7.4.
Remove the label from the top of the label stack. If there is another label in the stack,
that label becomes the label at the top of the label stack. Otherwise, the packet is
forwarded as a native protocol packet (typically, as an IP packet).
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Intermediate (Transit) and Egress Routers for Static LSPs on page 196
•
swap on page 327
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
preference
Syntax
Hierarchy Level
Release Information
Description
preference preference;
[edit logical-systems logical-system-name protocols mpls],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
(primary | secondary) path-name],
[edit logical-systems logical-system-name protocols mpls
static-label-switched-path lsp-name ingress],
[edit protocols mpls],
[edit protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name (primary | secondary) path-name],
[edit protocols mpls static-label-switched-path lsp-name ingress]
Statement introduced before Junos OS Release 7.4.
Preference for the route.
You can optionally configure multiple LSPs between the same pair of ingress and egress
routers. This is useful for balancing the load among the LSPs because all LSPs, by default,
have the same preference level. To prefer one LSP over another, set different preference
levels for individual LSPs. The LSP with the lowest preference value is used. The default
preference for LSPs is lower (more preferred) than all learned routes except direct
interface routes.
Options
preference—Preference to assign to the route. A route with a lower preference value is
preferred.
Range: 1 through 255
Default: 5 for static MPLS LSPs, 7 for RSVP MPLS LSPs, 9 for LDP MPLS LSPs
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Preference Values for LSPs on page 157
•
Configuring the Ingress Router for Static LSPs on page 193
•
Configuring the Intermediate (Transit) and Egress Routers for Static LSPs on page 196
Copyright © 2011, Juniper Networks, Inc.
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primary
Syntax
Hierarchy Level
Release Information
Description
primary path-name {
adaptive;
admin-group {
exclude [ group-names ];
include-all [ group-names ];
include-any [ group-names ];
}
bandwidth bps;
class-of-service cos-value;
hop-limit number;
no-cspf;
no-decrement-ttl;
optimize-timer seconds;
preference preference;
priority setup-priority reservation-priority;
(record | no-record);
select (manual | unconditional);
standby;
}
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name]
Statement introduced before Junos OS Release 7.4.
Specify the primary path to use for an LSP. You can configure only one primary path.
You can optionally specify preference, CoS, and bandwidth values for the primary path,
which override any equivalent values that you configure for the LSP (at the [edit mpls
label-switched-path lsp-name] hierarchy level).
Options
path-name—Name of a path that you created with the path statement.
The remaining statements are explained separately.
Required Privilege
Level
Related
Documentation
308
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Primary and Secondary LSPs on page 131
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
priority
Syntax
Hierarchy Level
Release Information
priority setup-priority reservation-priority;
[edit logical-systems logical-system-name protocols mpls],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
(primary | secondary) path-name],
[edit protocols mpls],
[edit protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name (primary | secondary) path-name]
Statement introduced before Junos OS Release 7.4.
Description
Configure the setup priority and reservation priority for an LSP. If insufficient link bandwidth
is available during session establishment, the setup priority is compared with other setup
priorities for established sessions on the link to determine whether some of them should
be preempted to accommodate the new session. Sessions with lower hold priorities are
preempted.
Options
reservation-priority—Reservation priority, used to keep a reservation after it has been set
up. A smaller number has a higher priority. The priority must be greater than or equal
to the setup priority to prevent preemption loops.
Range: 0 through 7, where 0 is the highest and 7 is the lowest priority.
Default: 0 (Once the session is set up, no other session can preempt it.)
setup-priority—Setup priority.
Range: 0 through 7, where 0 is the highest and 7 is the lowest priority.
Default: 7 (The session cannot preempt any existing sessions.)
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Priority and Preemption for LSPs on page 161
Copyright © 2011, Juniper Networks, Inc.
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protection-revert-time
Syntax
Hierarchy Level
Release Information
Description
protection-revert-time seconds;
[edit logical-systems logical-system-name protocols mpls interface interface-name static],
[edit protocols mpls interface interface-name static]
Statement introduced in Junos OS Release 10.1.
Specify the amount of time (in seconds) that a static LSP must wait before traffic reverts
from the bypass path to the original path.
If you have configured a value of 0 seconds for the protection-revert-time statement and
traffic is switched to the bypass path, the traffic remains on that path indefinitely. It is
never switched back to the original path unless the bypass path is down or you intervene.
Options
seconds—Time in seconds.
Range: 0 through 65,535 seconds
Default: 5 seconds
Required Privilege
Level
Related
Documentation
310
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Static LSPs on page 193
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
push
Syntax
Hierarchy Level
Release Information
Description
Options
push out-label;
[edit logical-systems logical-system-name protocols mpls
static-label-switched-path lsp-name bypass],
[edit logical-systems logical-system-name protocols mpls
static-label-switched-path lsp-name ingress],
[edit protocols mpls static-label-switched-path lsp-name bypass],
[edit protocols mpls static-label-switched-path lsp-name ingress]
Statement introduced before Junos OS Release 7.4.
Add a new label to the top of the label stack. This statement is used to configure static
LSPs at ingress routers and to configure bypass LSPs for static LSPs.
out-label—Manually assigned outgoing label value.
Range: 0 through 1,048,575.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
pop on page 306
•
swap on page 327
•
Configuring the Ingress Router for Static LSPs on page 193
Copyright © 2011, Juniper Networks, Inc.
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random
Syntax
Hierarchy Level
Release Information
Description
(random | least-fill | most-fill);
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name]
Statement introduced before Junos OS Release 7.4.
Configure the preferred path when several equal-cost candidate paths to a destination
exist, and prefer the path with the highest available bandwidth (with the largest minimum
available bandwidth ratio). The available bandwidth ratio of a link is the available
bandwidth on a link divided by the maximum reservable bandwidth on the link.
•
least-fill—Prefer the path with the most available bandwidth (with the largest minimum
available bandwidth ratio).
•
most-fill—Prefer the path with the least available bandwidth (with the minimum
available bandwidth ratio). The minimum available bandwidth ratio of a path is the
smallest available bandwidth ratio belonging to any of the links in the path.
•
Default
Required Privilege
Level
Related
Documentation
312
random—Choose the path at random.
random
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring CSPF Tie Breaking on page 139
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
record
Syntax
Hierarchy Level
Release Information
Description
Default
Required Privilege
Level
Related
Documentation
(record | no-record);
[edit logical-systems logical-system-name protocols mpls],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit logical-systems logical-system-name protocols mpls label-switched-path (primary |
secondary) path-name],
[edit protocols mpls],
[edit protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name (primary | secondary) path-name]
Statement introduced before Junos OS Release 7.4.
Specify whether an LSP should actively record the routes in the path. Recording routes
requires that all transit routers support the RSVP Record Route object. Recording routes
can be useful for diagnostics and loop detection.
Record routes.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Disabling Path Route Recording on page 157
retry-limit
Syntax
Hierarchy Level
Release Information
Description
Options
retry-limit number;
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name],
Statement introduced before Junos OS Release 7.4.
Maximum number of times the ingress router tries to establish the primary path. This
counter is reset each time a primary path is created successfully. When the limit is
exceeded, no more connection attempts are made. Intervention is then required to restart
the connection.
number—Maximum number of tries to establish the primary path.
Range: 0 through 10,000
Default: 0 (The ingress node never stops trying to establish the primary path.)
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Connection Between Ingress and Egress Routers on page 137
Copyright © 2011, Juniper Networks, Inc.
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retry-timer
Syntax
Hierarchy Level
Release Information
Description
Options
retry-timer seconds;
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name]
Statement introduced before Junos OS Release 7.4.
Amount of time the ingress router waits between attempts to establish the primary path.
seconds—Amount of time between attempts to connect to the primary path.
Range: 1 through 600 seconds
Default: 30 seconds
Required Privilege
Level
Related
Documentation
314
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Connection Between Ingress and Egress Routers on page 137
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
revert-timer
Syntax
Hierarchy Level
Release Information
Description
revert-timer seconds;
[edit logical-systems logical-system-name protocols mpls],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit protocols mpls],
[edit protocols mpls label-switched-path lsp-name]
Statement introduced before Junos OS Release 7.4.
BFD behavior modified in Junos OS Release 9.0.
Specify the amount of time (in seconds) that an LSP must wait before traffic reverts to
a primary path. If during this time the primary path experiences any connectivity problem
or stability problem, the timer is restarted.
If you have configured BFD on the LSP, the Junos OS waits until the BFD session is restored
before starting the revert timer counter.
If you have configured a value of 0 seconds for the revert-timer statement and traffic is
switched to the secondary path, the traffic remains on that path indefinitely. It is never
switched back to the primary path unless you intervene.
Options
seconds—Time in seconds.
Range: 0 through 65,535 seconds
Default: 60 seconds
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Revert Timer for LSPs on page 132
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
rpf-check-policy
Syntax
Hierarchy Level
Release Information
Description
Options
Required Privilege
Level
Related
Documentation
316
rpf-check-policy policy;
[edit logical-systems logical-system-name routing-options multicast],
[edit routing-options multicast]
Statement introduced in Junos OS Release 8.0.
Enable you to control whether a reverse path forwarding (RPF) check is performed for
a source and group entry before installing a route in the multicast forwarding cache. This
makes it possible to use point-to-multipoint LSPs to distribute multicast traffic to Protocol
Independent Multicast (PIM) islands situated downstream from the egress routers of
the point-to-multipoint LSPs.
policy—Name of the RPF check routing policy.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring a Multicast RPF Check Policy for Point-to-Multipoint LSPs on page 206
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
rsvp-error-hold-time
Syntax
Hierarchy Level
Release Information
Description
rsvp-error-hold-time seconds;
[edit logical-systems logical-system-name protocols mpls],
[edit protocols mpls]
Statement introduced before Junos OS Release 7.4.
Amount of time MPLS retains RSVP PathErr messages and considers them for CSPF
computations. The more time you configure, the more time a source node (ingress of an
RSVP LSP) can have to learn about the failures of its LSP by monitoring PathErr messages
transmitted from downstream nodes.
Information from the PathErr messages is incorporated into subsequent LSP
computations, which can improve the accuracy and speed of LSP setup. Some PathErr
messages are also used to update traffic engineering database bandwidth information,
reducing inconsistencies between the database and the network.
Options
seconds—Amount of time MPLS retains RSVP PathErr messages and considers them for
CSPF computations.
Range: 0 through 240 seconds
Default: 25 seconds
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Improving Traffic Engineering Database Accuracy with RSVP PathErr Messages on
page 63
Copyright © 2011, Juniper Networks, Inc.
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secondary
Syntax
Hierarchy Level
Release Information
Description
secondary path-name {
adaptive;
admin-group {
exclude [ group-names ];
include-all [ group-names ];
include-any [ group-names ];
}
bandwidth bps;
class-of-service cos-value;
hop-limit number;
no-cspf;
no-decrement-ttl;
optimize-timer seconds;
preference preference;
priority setup-priority reservation-priority;
(record | no-record);
retry-limit number;
retry-timer seconds;
select (manual | unconditional);
standby;
}
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name]
Statement introduced before Junos OS Release 7.4.
Specify one or more secondary paths to use for the LSP. You can configure more than
one secondary path. All secondary paths are equal, and the first one that is available is
chosen.
You can specify secondary paths even if you have not specified any primary paths.
Optionally, you can specify preference, CoS, and bandwidth values for the secondary
path, which override any equivalent values that you configure for the LSP (at the [edit
mpls label-switched-path] hierarchy level).
Options
path-name—Name of a path that you created with the path statement.
The remaining statements are explained separately.
Required Privilege
Level
Related
Documentation
318
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Primary and Secondary LSPs on page 131
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
select
Syntax
Hierarchy Level
Release Information
select (manual | unconditional);
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
(primary | secondary) path-name],
[edit protocols mpls label-switched-path lsp-name (primary | secondary) path-name]
Statement introduced before Junos OS Release 7.4.
Description
Specify the conditions under which the path is selected to carry traffic. The manual and
unconditional options are mutually exclusive.
Options
manual—The path is selected for carrying traffic if it is up and stable for at least the revert
timer window (potentially before the revert timer has elapsed). Traffic is sent to
other working paths if the current path is down or degraded (receiving errors).
unconditional—The path is always selected for carrying traffic, even if it is currently down
or degraded (receiving errors).
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Specifying the Conditions for Path Selection on page 133
signal-bandwidth
Syntax
Hierarchy Level
Release Information
Description
Options
signal-bandwidth type;
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
lsp-attributes],
[edit protocols mpls label-switched-path lsp-name lsp-attributes]
Statement introduced before Junos OS Release 7.4.
Specify the bandwidth encoding of the signal used for path computation and admission
control.
type—Configure the type of bandwidth encoding used on the LSP. It can be any of the
following values: 10gigether, ds1, ds3, e1, e3, ethernet, fastether, gigether, stm-1, stm-4,
stm-16, stm-64, stm-256, sts-1, vt1-5, or vt2.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Signal Bandwidth Type on page 559
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
smart-optimize-timer
Syntax
Hierarchy Level
Release Information
Description
Default
Options
smart-optimize-timer seconds;
[edit logical-systems logical-system-name protocols mpls],
[edit protocols mpls]
Statement introduced before Junos OS Release 7.4.
Enable the smart optimization timer. When you enable the smart optimization timer on
a router, the Junos OS operates on the assumption that the original LSP path is preferable
to any alternate or secondary path. When you enable the smart optimization timer and
an LSP fails and its traffic is switched to an alternate path, the smart optimization timer
starts and waits 3 minutes (this time is configurable). After 3 minutes have passed, the
LSP is switched back to the original path. If the original path fails again and the LSP is
switched to an alternate path again, the router waits 1 hour before attempting to switch
the LSP back to its original path.
The smart optimization timer is disabled by default.
seconds—(Optional) Specify the number of seconds to wait before switching an LSP
back to its original path. If you do not specify the number of seconds, the default
value is used.
Range: 0 through 65,535 seconds
Default: 180 seconds
Required Privilege
Level
Related
Documentation
320
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Smart Optimize Timer on page 165
•
Optimizing Signaled LSPs on page 161
•
optimize-aggressive on page 301
•
optimize-timer on page 302
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
soft-preemption
Syntax
Hierarchy Level
Release Information
Description
Required Privilege
Level
Related
Documentation
soft-preemption;
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name]
Statement introduced before Junos OS Release 7.4.
Attempt to establish a new path for a preempted LSP before tearing it down.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring MPLS Soft Preemption on page 144
srlg
Syntax
Hierarchy Level
Release Information
Description
Options
srlg {
srlg-name {
srlg-cost srlg-cost;
srlg-value srlg-value;
}
}
[edit routing-options],
[edit logical-systems logical-system-name routing-options]
[edit protocols mpls interface interface-name]
Statement introduced in Junos OS Release 11.4.
Configure Shared Risk Link Group (SRLG) parameters.
srlg-cost srlg-cost—Specify a cost for the SRLG ranging from 1 through 65535.
srlg-value srlg-value—Specify a Group ID for the SRLG ranging from 1 through 4294967295.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Example: Configuring SRLG on page 71
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
srlg-cost
Syntax
Hierarchy Level
Release Information
Description
Required Privilege
Level
Related
Documentation
srlg-cost srlg-cost;
[edit routing-options srlg],
[edit logical-systems logical-system-name routing-options srlg]
Statement introduced in Junos OS Release 11.4.
Specify a cost for the Shared Risk Link Group (SRLG) ranging from 1 through 65535.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Example: Configuring SRLG on page 71
srlg-value
Syntax
Hierarchy Level
Release Information
Description
Required Privilege
Level
Related
Documentation
322
srlg-value srlg-value;
[edit routing-options srlg],
[edit logical-systems logical-system-name routing-options srlg]
Statement introduced in Junos OS Release 11.4.
Specify a Group ID for the Shared Risk Link Group (SRLG) ranging from 1 through
4294967295.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Example: Configuring SRLG on page 71
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
standby
Syntax
Hierarchy Level
Release Information
Description
Required Privilege
Level
Related
Documentation
standby;
[edit logical-systems logical-system-name protocols mpls],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
(primary | secondary) path-name],
[edit protocols mpls],
[edit protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name (primary | secondary) path-name]
Statement introduced before Junos OS Release 7.4.
Have the path remain up at all times to provide instant switchover if connectivity problems
occur.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Hot Standby of Secondary Paths on page 166
Copyright © 2011, Juniper Networks, Inc.
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static-label-switched-path
Syntax
Hierarchy Level
Release Information
Description
Options
static-label-switched-path lsp-name {
bypass bypass-name {
bandwidth bps;
description string;
next-hop (address | interface-name | address/interface-name);
push out-label;
to address;
}
ingress {
bandwidth bps;
class-of-service cos-value;
description string;
install {
destination-prefix <active>;
}
link-protection bypass-name name;
metric metric;
next-hop (address | interface-name | address/interface-name);
node-protection bypass-name name next-next-label label;
no-install-to-address;
policing {
filter filter-name;
no-auto-policing;
}
preference preference;
push out-label;
to address;
}
transit incoming-label {
bandwidth bps;
description string;
link-protection bypass-name name;
next-hop (address | interface-name | address/interface-name);
node-protection bypass-name name next-next-label label;
pop;
swap out-label;
}
[edit logical-systems logical-system-name protocols mpls],
[edit protocols mpls]
Statement introduced in Junos OS Release 10.1.
Configure a static LSP.
lsp-name—Name of the path.
The remaining statements are explained separately.
Required Privilege
Level
324
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
Related
Documentation
•
Configuring Static LSPs on page 193
Copyright © 2011, Juniper Networks, Inc.
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statistics
Syntax
Hierarchy Level
Release Information
Description
Options
statistics {
auto-bandwidth;
file filename <files number> <size size> <world-readable | no-world-readable>;
interval seconds;
}
[edit logical-systems logical-system-name protocols mpls],
[edit protocols mpls]
Statement introduced before Junos OS Release 7.4.
Enable MPLS statistics collection and reporting.
auto-bandwidth—Collect statistics related to automatic bandwidth.
file filename—(Optional) Name of the file to receive the output. We recommend that you
place MPLS tracing output in the file mpls-stat in the /var/log directory.
files number—(Optional) Maximum number of trace files. When a trace file named file
reaches its maximum size, it is renamed file.0, then file.1, and so on, until the maximum
number of files is reached. Then, the oldest file is overwritten.
Range: 2 or more
Default: 2 files
If you specify a maximum number of files, you also must specify a maximum file size with
the size option.
interval seconds—Interval at which to periodically collect statistics.
Range: 1 through 65,535
Default: 300 seconds
no-world-readable—(Optional) Prevent users from reading the log file.
size size—(Optional) Maximum size of each file, in kilobytes (KB), megabytes (MB),
or gigabytes (GB). When a file named file reaches this size, it is renamed file.0. When
the file again reaches its maximum size, file.0 is renamed file.1 and file is renamed
file.0. This renaming scheme continues until the maximum number of files is reached.
Then the oldest trace file is overwritten.
Syntax: Syntax: xk to specify KB, xm to specify MB, or xg to specify GB
Range: 10 KB through the maximum file size supported on your system
Default: 1 MB
If you specify a maximum file size, you also must specify a maximum number of files with
the files option.
world-readable—(Optional) Enable users to read the log file.
326
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Chapter 10: Summary of MPLS Configuration Statements
Required Privilege
Level
Related
Documentation
routing and trace—To view this statement in the configuration.
routing-control and trace-control—To add this statement to the configuration.
•
Configuring MPLS to Gather Statistics on page 222
•
Configuring MPLS Statistics for Automatic Bandwidth Allocation on page 146
swap
Syntax
Hierarchy Level
Release Information
Description
Options
swap out-label;
[edit logical-systems logical-system-name protocols mpls static-label-switched-path
lsp-name transit incoming-label],
[edit protocols mpls static-label-switched-path lsp-name transit incoming-label]
Statement introduced before Junos OS Release 7.4.
Remove the label at the top of the label stack and replace it with the specified label.
Manually assigned incoming labels can have values from 1,000,000 through 1,048,575.
This statement is used to configure static LSPs at transit routers.
out-label—Manually assigned outgoing label value.
Range: 0 through 1,048,575
Default: If you do not define the out-label option, the original label value remains
unchanged.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
pop on page 306
•
push on page 311
•
Configuring the Intermediate (Transit) and Egress Routers for Static LSPs on page 196
Copyright © 2011, Juniper Networks, Inc.
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switch-away-lsps
Syntax
Hierarchy Level
Release Information
Description
switch-away-lsps;
[edit logical-systems logical-systems-name protocols mpls interface interface-name],
[edit protocols mpls interface interface-name]
Statement introduced in Junos OS Release 10.2.
(MX Series routers only) Enable you to switch an LSP away from a network node using
a bypass LSP. This feature could be used in maintenance of active networks when a
network device needs to be replaced without interrupting traffic passing through the
network. The LSPs can be either static or dynamic. Configure this statement only after
you have configured and committed the always-mark-connection-protection-tlv statement.
The always-mark-connection-protection-tlv statement marks all OAM traffic transiting
this interface in preparation for switching the traffic to an alternate path based on the
OAM functionality. When you configure the switch-away-lsps statement, traffic is switched
to the bypass LSP.
Required Privilege
Level
Related
Documentation
328
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Switching LSPs Away from a Network Node on page 365
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
switching-type
Syntax
Hierarchy Level
Release Information
Description
Default
Required Privilege
Level
Related
Documentation
switching-type (fiber | lambda | psc-1 | tdm);
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name
lsp-attributes],
[edit protocols mpls label-switched-path lsp-name lsp-attributes]
Statement introduced before Junos OS Release 7.4.
Specify the switching method for the LSP. The switching method can be one of the
following values:
•
fiber—Fiber switching
•
lambda—Lambda switching
•
psc-1—Packet switching
•
tdm—Time-division multiplexing (TDM) switching
psc-1
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring MPLS LSPs for GMPLS on page 557
Copyright © 2011, Juniper Networks, Inc.
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te-class-matrix
Syntax
Hierarchy Level
Release Information
Description
Default
te-class-matrix {
tenumber {
priority priority;
traffic-class {
ctnumber priority priority;
}
}
}
[edit logical-systems logical-system-name protocols mpls diffserv-te],
[edit protocols mpls diffserv-te]
Statement introduced before Junos OS Release 7.4.
Specify the traffic engineering class matrix for a multiclass LSP or a DiffServ-aware traffic
engineering LSP.
The default traffic engineering class matrix is:
te-class-matrix {
te0 traffic-class ct0 priority 7;
te1 traffic-class ct1 priority 7;
te2 traffic-class ct2 priority 7;
te3 traffic-class ct3 priority 7;
te4 traffic-class ct0 priority 0;
te5 traffic-class ct1 priority 0;
te6 traffic-class ct2 priority 0;
te7 traffic-class ct3 priority 0;
}
If you define any of the traffic engineering classes, all the default values are dropped.
Options
ctnumber—Specify the number of the class type. It can be one of four values: ct0, ct1, ct2,
or ct3.
priority priority—Specify the priority of the class type. It can be one of eight values from
0 through 7.
tenumber—Specify the number of the traffic engineering class. It can be one of eight
values: te0, te1, te2, te3, te4, te5, te6, or te7. You must configure the traffic engineering
classes in order, starting with te0.
traffic-class—Specify the traffic class for the traffic engineering class.
Required Privilege
Level
Related
Documentation
330
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Traffic Engineering Classes on page 177
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
to
Syntax
Hierarchy Level
Release Information
Description
Options
Required Privilege
Level
Related
Documentation
to address;
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit logical-systems logical-system-name protocols mpls static-label-switched-path
lsp-name bypass],
[edit logical-systems logical-system-name protocols mpls static-label-switched-path
lsp-name ingress],
[edit protocols mpls label-switched-path lsp-name],
[edit protocols mpls static-label-switched-path lsp-name bypass],
[edit protocols mpls static-label-switched-path lsp-name ingress]
Statement introduced before Junos OS Release 7.4.
Specify the egress router of a dynamic LSP.
address—Address of the egress router.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Egress Router Address for LSPs on page 130
Copyright © 2011, Juniper Networks, Inc.
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traceoptions
Syntax
Hierarchy Level
Release Information
Description
traceoptions {
file filename <files number> <size size> <world-readable | no-world-readable>;
flag flag;
}
[edit logical-systems logical-system-name protocols mpls],
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit protocols mpls],
[edit protocols mpls label-switched-path lsp-name]
Statement introduced before Junos OS Release 7.4.
Configure MPLS tracing options at the protocol level or for a label-switched path.
To specify more than one tracing operation, include multiple flag statements.
Default
Options
The default MPLS protocol-level tracing options are inherited from the routing protocols
traceoptions statement included at the [edit routing-options] hierarchy level.
filename—Name of the file to receive the output of the tracing operation. All files are
placed in the directory /var/log. We recommend that you place MPLS tracing output
in the file mpls-log.
files number—(Optional) Maximum number of trace files. When a trace file named
trace-file reaches its maximum size, it is renamed trace-file.0, then trace-file.1, and
so on, until the maximum number of trace files is reached. Then the oldest trace file
is overwritten.
Range: 2 through 1000
Default: 2 files
If you specify a maximum number of files, you must also include the size statement to
specify the maximum file size.
flag—Tracing operation to perform. To specify more than one tracing operation, include
multiple flag statements.
MPLS Tracing Flags
332
•
all—Trace all operations
•
connection—All circuit cross-connect (CCC) activity
•
connection-detail—Detailed CCC activity
•
cspf—CSPF computations
•
cspf-link—Links visited during CSPF computations
•
cspf-node—Nodes visited during CSPF computations
•
error—MPLS error packets
Copyright © 2011, Juniper Networks, Inc.
Chapter 10: Summary of MPLS Configuration Statements
•
graceful-restart—Trace MPLS graceful restart events
•
lsping—Trace lsping packets and return codes
•
nsr-synchronization—Trace NSR synchronization events
•
nsr-synchronization-detail—Trace NSR synchronization events in detail
•
state—All LSP state transitions
•
static—Trace static label-switched path
•
timer—Timer usage
no-world-readable—(Optional) Allow only certain users to read the log file.
size size—(Optional) Maximum size of each trace file, in kilobytes (KB), megabytes (MB),
or gigabytes (GB). When a trace file named trace-file reaches this size, it is renamed
trace-file.0. When the trace-file again reaches this size, trace-file.0 is renamed
trace-file.1 and trace-file is renamed trace-file.0. This renaming scheme continues
until the maximum number of trace files is reached. Then the oldest trace file is
overwritten.
Syntax: xk to specify KB, xm to specify MB, or xg to specify GB
Range: 10 KB through the maximum file size supported on your system
Default: 1 MB
If you specify a maximum file size, you must also include the files statement to specify
the maximum number of files.
world-readable—(Optional) Allow any user to read the log file.
Required Privilege
Level
Related
Documentation
routing and trace—To view this statement in the configuration.
routing-control and trace-control—To add this statement to the configuration.
•
Tracing MPLS and LSP Packets and Operations on page 237
Copyright © 2011, Juniper Networks, Inc.
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traffic-engineering
Syntax
Hierarchy Level
Release Information
Description
Default
Options
traffic-engineering (bgp | bgp-igp | bgp-igp-both-ribs | mpls-forwarding);
[edit logical-systems logical-system-name protocols mpls],
[edit protocols mpls]
Statement introduced before Junos OS Release 7.4.
Select whether MPLS performs traffic engineering on BGP destinations only or on both
BGP and IGP destinations. Affects only LSPs originating from this router, not transit or
egress LSPs.
bgp
bgp—On BGP destinations only. Ingress routes are installed in the inet.3 routing table.
bgp-igp—On both BGP and IGP destinations. Ingress routes are installed in the inet.0
routing table. If IGP shortcuts are enabled, the shortcut routes are automatically
installed in the inet.0 routing table.
bgp-igp-both-ribs—On both BGP and IGP destinations. Ingress routes are installed in the
inet.0 and inet.3 routing tables. This option is used to support VPNs.
mpls-forwarding—On both BGP and IGP destinations. Use ingress routes for forwarding
only, not for routing.
Required Privilege
Level
Related
Documentation
334
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Traffic Engineering for LSPs on page 216
Copyright © 2011, Juniper Networks, Inc.
PART 3
RSVP
•
RSVP Overview on page 337
•
RSVP Configuration Guidelines on page 355
•
Summary of RSVP Configuration Statements on page 387
Copyright © 2011, Juniper Networks, Inc.
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336
Copyright © 2011, Juniper Networks, Inc.
CHAPTER 11
RSVP Overview
This chapter discusses the following topics:
•
RSVP Introduction on page 338
•
Supported RSVP Standards on page 338
•
Junos OS RSVP Protocol Implementation on page 340
•
RSVP Operation Overview on page 340
•
RSVP Authentication on page 341
•
RSVP and IGP Hello Packets and Timers on page 341
•
RSVP Message Types on page 341
•
Path Messages on page 342
•
Resv Messages on page 342
•
PathTear Messages on page 342
•
ResvTear Messages on page 342
•
PathErr Messages on page 343
•
ResvErr Messages on page 343
•
ResvConfirm Messages on page 343
•
RSVP Reservation Styles on page 343
•
RSVP Refresh Reduction on page 344
•
MTU Signaling in RSVP on page 345
•
How the Correct MTU Is Signaled in RSVP on page 346
•
Determining an Outgoing MTU Value on page 346
•
MTU Signaling in RSVP Limitations on page 347
•
Fast Reroute, Node Protection, and Link Protection on page 347
•
Link Protection on page 348
•
Multiple Bypass LSPs on page 349
•
Node Protection on page 349
•
RSVP Graceful Restart on page 350
•
RSVP Graceful Restart Standard on page 351
•
RSVP Graceful Restart Terminology on page 351
Copyright © 2011, Juniper Networks, Inc.
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•
RSVP Graceful Restart Operation on page 351
•
Processing the Restart Cap Object on page 352
RSVP Introduction
RSVP is a resource reservation setup protocol that is used by both network hosts and
routers. Hosts use RSVP to request a specific class of service (CoS) from the network
for particular application flows. Routers use RSVP to deliver CoS requests to all routers
along the data path. RSVP also can maintain and refresh states for a requested CoS
application flow.
RSVP treats an application flow as a simplex connection. That is, the CoS request travels
only in one direction—from the sender to the receiver. RSVP is a transport layer protocol
that uses IP as its network layer. However, RSVP does not transport application flows.
Rather, it is more of an Internet control protocol, similar to the Internet Control Message
Protocol (ICMP) and Internet Group Management Protocol (IGMP). RSVP runs as a
separate software process in the Junos OS and is not in the packet forwarding path.
RSVP is not a routing protocol, but rather is designed to operate with current and future
unicast and multicast routing protocols. The routing protocols are responsible for choosing
the routes to use to forward packets, and RSVP consults local routing tables to obtain
routes. RSVP only ensures the CoS of packets traveling along a data path.
The receiver in an application flow requests the preferred CoS from the sender. To do
this, the receiver issues an RSVP CoS request on behalf of the local application. The
request propagates to all routers in reverse direction of the data paths toward the sender.
In this process, RSVP requests might be merged, resulting in a protocol that scales well
when there are a large number of receivers.
Because the number of receivers in an application flow is likely to change and the flow
of delivery paths might change during the life of an application flow, RSVP takes a
soft-state approach in its design, creating and removing the protocol states in routers
and hosts incrementally over time. RSVP sends periodic refresh messages to maintain
its state and to recover from occasional lost messages. In the absence of refresh
messages, RSVP states automatically time out and are deleted.
Supported RSVP Standards
The Junos OS substantially supports the following RFCs and Internet drafts, which define
standards for RSVP.
338
•
RFC 2205, Resource ReSerVation [sic] Protocol (RSVP)—Version 1 Functional
Specification
•
RFC 2210, The Use of RSVP with IETF Integrated Services
•
RFC 2211, Specification of the Controlled-Load Network Element Service
•
RFC 2212, Specification of Guaranteed Quality of Service
•
RFC 2215, General Characterization Parameters for Integrated Service Network Elements
•
RFC 2745, RSVP Diagnostic Messages
Copyright © 2011, Juniper Networks, Inc.
Chapter 11: RSVP Overview
•
RFC 2747, RSVP Cryptographic Authentication (updated by RFC 3097)
•
RFC 2961, RSVP Refresh Overhead Reduction Extensions
•
RFC 3097, RSVP Cryptographic Authentication—Updated Message Type Value
•
RFC 3209, RSVP-TE: Extensions to RSVP for LSP Tunnels
The Null Service Object for maximum transmission unit (MTU) signaling in RSVP is
not supported.
•
RFC 3473, Generalized Multi-Protocol [sic] Label Switching (GMPLS) Signaling Resource
ReserVation [sic] Protocol-Traffic Engineering (RSVP-TE) Extensions
Only Section 9, “Fault Handling,” is supported.
•
RFC 3477, Signalling Unnumbered Links in Resource ReSerVation [sic] Protocol - Traffic
Engineering (RSVP-TE)
•
RFC 4090, Fast Reroute Extensions to RSVP-TE for LSP Tunnels
Node protection in facility backup is not supported.
•
RFC 4203, OSPF Extensions in Support of Generalized Multi-Protocol [sic] Label Switching
(GMPLS)
(OSPF extensions can carry traffic engineering information over unnumbered links.)
•
RFC 4558, Node-ID Based Resource Reservation Protocol (RSVP) Hello: A Clarification
Statement
•
RFC 4561, Definition of a Record Route Object (RRO) Node-Id Sub-Object
The RRO node ID subobject is for use in inter-AS link and node protection configurations.
•
Internet draft draft-ietf-mpls-rsvp-te-p2mp-01.txt, Extensions to RSVP-TE for Point to
Multipoint TE LSPs (expires June 2005)
The following RFCs do not define standards, but provide information about RSVP and
related technologies. The IETF classifies them variously as “Experimental” or
“Informational.”
Related
Documentation
•
RFC 2209, Resource ReSerVation [sic] Protocol (RSVP)—Version 1 Message Processing
Rules
•
RFC 2216, Network Element Service Specification Template
•
RFC 4125, Maximum Allocation Bandwidth Constraints Model for Diffserv-aware MPLS
Traffic Engineering
•
RFC 4127, Russian Dolls Bandwidth Constraints Model for Diffserv-aware MPLS Traffic
Engineering
•
Supported GMPLS Standards on page 541
•
Supported LDP Standards on page 426
•
Supported MPLS Standards on page 24
•
Accessing Standards Documents on the Internet
Copyright © 2011, Juniper Networks, Inc.
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Junos OS RSVP Protocol Implementation
The Junos implementation of RSVP supports RSVP version 1. The software includes
support for all mandatory objects and RSVP message types, and supports message
integrity and node authentications through the Integrity object.
The primary purpose of the Junos RSVP software is to support dynamic signaling within
MPLS label-switched paths (LSPs). Supporting resource reservations over the Internet
is only a secondary purpose of the Junos OS implementation. Since supporting resource
reservations is secondary, the Junos RSVP software does not support the following
features:
•
IP multicasting sessions.
•
Traffic control. The software cannot make resource reservations for real-time video
or audio sessions.
With regard to the protocol mechanism, packet processing, and RSVP objects supported,
the Junos OS implementation of the software is interoperable with other RSVP
implementations.
RSVP Operation Overview
RSVP creates independent sessions to handle each data flow. A session is identified by
a combination of the destination address, an optional destination port, and a protocol.
Within a session, there can be one or more senders. Each sender is identified by a
combination of its source address and source port. An out-of-band mechanism, such as
a session announcement protocol or human communication, is used to communicate
the session identifier to all senders and receivers.
A typical RSVP session involves the following sequence of events:
1.
A potential sender starts sending RSVP path messages to the session address.
2. A receiver, wanting to join the session, registers itself if necessary. For example, a
receiver in a multicast application would register itself with IGMP.
3. The receiver receives the path messages.
4. The receiver sends appropriate Resv messages toward the sender. These messages
carry a flow descriptor, which is used by routers along the path to make reservations
in their link-layer media.
5. The sender receives the Resv message and then starts sending application data.
This sequence of events is not necessarily strictly synchronized. For example, receivers
can register themselves before receiving path messages from the sender, and application
data can flow before the sender receives Resv messages. Application data that is delivered
before the actual reservation contained in the Resv message typically is treated as
best-effort, non-real-time traffic with no CoS guarantee.
340
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Chapter 11: RSVP Overview
RSVP Authentication
The Junos OS supports both the RSVP authentication style described in RFC 2747
(allowing for multivendor compatibility) and the RSVP authentication style described
in Internet draft draft-ietf-rsvp-md5-03.txt. The Junos OS uses the authentication style
described in Internet draft draft-ietf-rsvp-md5-08.txt by default. If the router receives
an RFC 2747-style RSVP authentication from a neighbor, it switches to this style of
authentication for that neighbor. The RSVP authentication style for each neighboring
router is determined separately.
RSVP and IGP Hello Packets and Timers
RSVP monitors the status of the interior gateway protocol (IGP) (IS-IS or OSPF) neighbors
and relies on the IGP protocols to detect when a node fails. If an IGP protocol declares
a neighbor down (because hello packets are no longer being received), RSVP also brings
down that neighbor. However, the IGP protocols and RSVP still act independently when
bringing a neighbor up.
In the Junos OS, RSVP typically relies on IGP hello packet detection to check for node
failures. RSVP sessions are kept up even if RSVP hello packets are no longer being
received, so long as the router continues to receive IGP hello packets. RSVP sessions are
maintained until either the router stops receiving IGP hello packets or the RSVP Path and
Resv messages time out. Configuring a short time for the IS-IS or OSPF hello timers
allows these protocols to detect node failures quickly.
RSVP hellos can be relied on when the IGP does not recognize a particular neighbor (for
example, if IGP is not enabled on the interface) or if the IGP is RIP (not IS-IS or OSPF).
Also, the equipment of other vendors might be configured to monitor RSVP sessions
based on RSVP hello packets. This equipment might also take an RSVP session down
due to a loss of RSVP hello packets.
We do not recommend configuring a short RSVP hello timer. If quick discovery of a failed
neighbor is needed, configure short IGP (OSPF or IS-IS) hello timers.
OSPF and IS-IS have infrastructure to manage rapid hello message sending and receiving
reliably, even if the routing protocols or some other process are straining the processing
capability of the router. Under the same circumstances, RSVP hellos might time out
prematurely even though the neighbor is functioning normally.
RSVP Message Types
RSVP uses the following types of messages to establish and remove paths for data flows,
establish and remove reservation information, confirm the establishment of reservations,
and report errors:
•
Path Messages on page 342
•
Resv Messages on page 342
•
PathTear Messages on page 342
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•
ResvTear Messages on page 342
•
PathErr Messages on page 343
•
ResvErr Messages on page 343
•
ResvConfirm Messages on page 343
Path Messages
Each sender host transmits path messages downstream along the routes provided by
the unicast and multicast routing protocols. Path messages follow the exact paths of
application data, creating path states in the routers along the way, thus enabling routers
to learn the previous-hop and next-hop node for the session. Path messages are sent
periodically to refresh path states.
The refresh interval is controlled by a variable called the refresh-time, which is the
periodical refresh timer expressed in seconds. A path state times out if a router does not
receive a specified number of consecutive path messages. This number is specified by
a variable called keep-multiplier. Path states are kept for ( (keep-multiplier + 0.5) x 1.5 x
refresh-time ) seconds.
Resv Messages
Each receiver host sends reservation request (Resv) messages upstream toward senders
and sender applications. Resv messages must follow exactly the reverse path of path
messages. Resv messages create and maintain a reservation state in each router along
the way.
Resv messages are sent periodically to refresh reservation states. The refresh interval is
controlled by the same refresh time variable, and reservation states are kept for
( (keep-multiplier + 0.5) x 1.5 x refresh-time ) seconds.
PathTear Messages
PathTear messages remove (tear down) path states as well as dependent reservation
states in any routers along a path. PathTear messages follow the same path as path
messages. A PathTear typically is initiated by a sender application or by a router when
its path state times out.
PathTear messages are not required, but they enhance network performance because
they release network resources quickly. If PathTear messages are lost or not generated,
path states eventually time out when they are not refreshed, and the resources associated
with the path are released.
ResvTear Messages
ResvTear messages remove reservation states along a path. These messages travel
upstream toward senders of the session. In a sense, ResvTear messages are the reverse
of Resv messages. ResvTear messages typically are initiated by a receiver application
or by a router when its reservation state times out.
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ResvTear messages are not required, but they enhance network performance because
they release network resources quickly. If ResvTear messages are lost or not generated,
reservation states eventually time out when they are not refreshed, and the resources
associated with the reservation are released.
PathErr Messages
When path errors occur (usually because of parameter problems in a path message),
the router sends a unicast PathErr message to the sender that issued the path message.
PathErr messages are advisory; these messages do not alter any path state along the
way.
ResvErr Messages
When a reservation request fails, a ResvErr error message is delivered to all the receivers
involved. ResvErr messages are advisory; these messages do not alter any reservation
state along the way.
ResvConfirm Messages
Receivers can request confirmation of a reservation request, and this confirmation is sent
with a ResvConfirm message. Because of the complex RSVP flow-merging rules, a
confirmation message does not necessarily provide end-to-end confirmation of the entire
path. Therefore, ResvConfirm messages are an indication, not a guarantee, of potential
success.
Juniper Networks routers never request confirmation using the ResvConfirm message;
however, a Juniper Networks router can send a ResvConfirm message if it receives a
request from another vendor's equipment.
RSVP Reservation Styles
A reservation request includes options for specifying the reservation style. The reservation
styles define how reservations for different senders within the same session are treated
and how senders are selected.
Two options specify how reservations for different senders within the same session are
treated:
•
Distinct reservation—Each receiver establishes its own reservation with each upstream
sender.
•
Shared reservation—All receivers make a single reservation that is shared among many
senders.
Two options specify how senders are selected:
•
Explicit sender—List all selected senders.
•
Wildcard sender—Select all senders, which then participate in the session.
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The following reservation styles, formed by a combination of these four options, currently
are defined:
•
Fixed filter (FF)—This reservation style consists of distinct reservations among explicit
senders. Examples of applications that use fixed-filter-style reservations are video
applications and unicast applications, which both require flows that have a separate
reservation for each sender. The fixed filter reservation style is enabled on RSVP LSPs
by default.
•
Wildcard filter (WF)—This reservation style consists of shared reservations among
wildcard senders. This type of reservation reserves bandwidth for any and all senders,
and propagates upstream toward all senders, automatically extending to new senders
as they appear. A sample application for wildcard filter reservations is an audio
application in which each sender transmits a distinct data stream. Typically, only a
few senders are transmitting at any one time. Such a flow does not require a separate
reservation for each sender; a single reservation is sufficient.
•
Shared explicit (SE)—This reservation style consists of shared reservations among
explicit senders. This type of reservation reserves bandwidth for a limited group of
senders. A sample application is an audio application similar to that described for
wildcard filter reservations.
RSVP Refresh Reduction
RSVP relies on soft-state to maintain the path and reservation states on each router. If
the corresponding refresh messages are not sent periodically, the states eventually time
out and reservations are deleted. RSVP also sends its control messages as IP datagrams
with no reliability guarantee. It relies on periodic refresh messages to handle the occasional
loss of Path or Resv messages.
The RSVP refresh reduction extensions, based on RFC 2961, addresses the following
problems that result from relying on periodic refresh messages to handle message loss:
•
Scalability—The scaling problem arises from the periodic transmission and processing
overhead of refresh messages, which increases as the number of RSVP sessions
increases.
•
Reliability and latency—The reliability and latency problem stems from the loss of
nonrefresh RSVP messages or one-time RSVP messages such as PathTear or PathErr.
The time to recover from such a loss is usually tied to refresh interval and the keepalive
timer.
The RSVP refresh reduction capability is advertised by enabling the refresh reduction
(RR) capable bit in the RSVP common header. This bit is only significant between RSVP
neighbors.
RSVP refresh reduction includes the following features:
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•
RSVP message bundling using the bundle message
•
RSVP Message ID to reduce message processing overhead
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•
Reliable delivery of RSVP messages using Message ID, Message Ack, and Message
Nack
•
Summary refresh to reduce the amount of information transmitted every refresh interval
The RSVP refresh reduction specification (RFC 2961) allows you to enable some or all
of the above capabilities on a router. It also describes various procedures that a router
can use to detect the refresh reduction capabilities of its neighbor.
The Junos OS supports all of the refresh reduction extensions, some of which can be
selectively enabled or disabled. The Junos OS supports Message ID and therefore can
perform reliable message delivery only for Path and Resv messages.
For information about how to configure RSVP refresh reduction, see “Configuring RSVP
Refresh Reduction” on page 357.
MTU Signaling in RSVP
The maximum transmission unit (MTU) is the largest size packet or frame, in bytes, that
can be sent in a network. An MTU that is too large might cause retransmissions. Too
small an MTU might cause the router to send and handle relatively more header overhead
and acknowledgments. There are default values for MTUs associated with various
protocols. You can also explicitly configure an MTU on an interface.
When an LSP is created across a set of links with different MTU sizes, the ingress router
does not know what the smallest MTU is on the LSP path. By default, the MTU for an
LSP is 1,500 bytes.
If this MTU is larger than the MTU of one of the intermediate links, traffic might be dropped,
because MPLS packets cannot be fragmented. Also, the ingress router is not aware of
this type of traffic loss, because the control plane for the LSP would still function normally.
To prevent this type of packet loss in MPLS LSPs, you can configure MTU signaling in
RSVP. This feature is described in RFC 3209. Juniper Networks supports the Integrated
Services object for MTU signaling in RSVP. The Integrated Services object is described
in RFCs 2210 and 2215. MTU signaling in RSVP is disabled by default.
To avoid packet loss due to MTU mismatches, the ingress router needs to do the following:
•
Signal the MTU on the RSVP LSP—To prevent packet loss from an MTU mismatch,
the ingress router needs to know what the smallest MTU value is along the path taken
by the LSP. Once this MTU value is obtained, the ingress router can assign it to the LSP.
•
Fragment packets—Using the assigned MTU value, packets that exceed the size of the
MTU can be fragmented into smaller packets on the ingress router before they are
encapsulated in MPLS and sent over the RSVP-signaled LSP.
Once both MTU signaling and packet fragmentation have been enabled on an ingress
router, any route resolving to an RSVP LSP on this router uses the signaled MTU value.
For information about how to configure this feature, see “Configuring MTU Signaling in
RSVP” on page 380.
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The following sections describe how MTU signaling in RSVP works:
•
How the Correct MTU Is Signaled in RSVP on page 346
•
Determining an Outgoing MTU Value on page 346
•
MTU Signaling in RSVP Limitations on page 347
How the Correct MTU Is Signaled in RSVP
How the correct MTU is signaled in RSVP varies depending on whether the network
devices (for example, routers) explicitly support MTU signaling in RSVP or not.
If the network devices support MTU signaling in RSVP, the following occur when you
enable MTU signaling:
•
The MTU is signaled from the ingress router to the egress router by means of the Adspec
object. Before forwarding this object, the ingress router enters the MTU value associated
with the interface over which the path message is sent. At each hop in the path, the
MTU value in the Adspec object is updated to the minimum of the received value and
the value of the outgoing interface.
•
The ingress router uses the traffic specification (Tspec) object to specify the parameters
for the traffic it is going to send. The MTU value signaled for the Tspec object at the
ingress router is the maximum MTU value (9192 bytes). This value does not change
en route to the egress router.
•
When the Adspec object arrives at the egress router, the MTU value is correct for the
path (meaning it is the smallest MTU value discovered). The egress router compares
the MTU value in the Adspec object to the MTU value in the Tspec object. It signals
the smaller MTU using the Flowspec object in the Resv message.
•
When the Resv object arrives at the ingress router, the MTU value in this object is used
as the MTU for the next hops that use the LSP.
In a network where there are devices that do not support MTU signaling in RSVP, you
might have the following behaviors:
•
If the egress router does not support MTU signaling in RSVP, the MTU is set to 1,500
bytes by default.
•
A Juniper Networks transit router that does not support MTU signaling in RSVP sets
an MTU value of 1,500 bytes in the Adspec object by default.
Determining an Outgoing MTU Value
The outgoing MTU value is the smaller of the values received in the Adspec object
compared to the MTU value of the outgoing interface. The MTU value of the outgoing
interface is determined as follows:
•
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If you configure an MTU value under the [family mpls] hierarchy level, this value is
signaled.
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•
If you do not configure an MTU, the inet MTU is signaled.
MTU Signaling in RSVP Limitations
The following are limitations to MTU signaling in RSVP:
•
Changes in the MTU value might cause a temporary loss of traffic in the following
situations:
•
For link protection and node protection, the MTU of the bypass is only signaled at
the time the bypass becomes active. During the time it takes for the new path MTU
to be propagated, packet loss might occur because of an MTU mismatch.
•
For fast reroute, the MTU of the path is updated only after the detour becomes active,
causing a delay in an update to the MTU at the ingress router. Until the MTU is
updated, packet loss might occur if there is an MTU mismatch.
In both cases, only packets that are larger than the detour or bypass MTU are lost.
•
When an MTU is updated, it triggers a change in the next hop. Any change in the next
hop causes the route statistics to be lost.
•
The minimum MTU supported for MTU signaling in RSVP is 1,488 bytes. This value
prevents a false or incorrectly configured value from being used.
•
For single-hop LSPs, the MTU value displayed by the show commands is the
RSVP-signaled value. However, this MPLS value is ignored and the correct IP value is
used.
Fast Reroute, Node Protection, and Link Protection
RFC 4090, Fast Reroute Extensions to RSVP-TE for LSP Tunnels, describes two different
types of traffic protection for RSVP-signaled LSPs:
•
One-to-one backup—In the Junos OS this type of traffic protection is provided by fast
reroute. Each LSP requires a protecting LSP to be signaled at each hop except the
egress router. This protecting LSP cannot be shared.
•
Facility backup—This is sometimes called many-to-one backup. In the Junos OS this
type of traffic protection is provided by node and link protection. Each LSP requires a
protecting LSP to be signaled at each hop except the egress router. Unlike fast reroute,
this protecting LSP can be shared by other LSPs.
Table 7 on page 347 summarizes the traffic protection types.
Table 7: One-to-One Backup Compared with Facility Backup
Comparison
One-to-One Backup
Facility Backup
Name of the protecting LSP
Detour LSP
Bypass LSP
Sharing of the protecting LSP
Cannot be shared
Can be shared by multiple
LSPs
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Table 7: One-to-One Backup Compared with Facility Backup (continued)
Comparison
One-to-One Backup
Facility Backup
Junos configuration statements
fast-reroute
node-link-protection and
link-protection
Link Protection
Link protection helps to ensure that traffic going over a specific interface to a neighboring
router can continue to reach this router if that interface fails. When link protection is
configured for an interface and an LSP that traverses this interface, a bypass LSP is
created that will handle this traffic if the interface fails. The bypass LSP uses a different
interface and path to reach the same destination. The path used can be configured
explicitly, or you can rely on CSPF. The RSVP metric for the bypass LSP is set in the range
of 20,000 through 29,999 (this value is not user configurable).
If a link-protected interface fails, traffic is quickly switched to the bypass LSP. Note that
a bypass LSP cannot share the same egress interface with the LSPs it monitors.
In Figure 22 on page 348, link protection is enabled on Interface B between Router 1 and
Router 2. It is also enabled on LSP A, an LSP that traverses the link between Router 1 and
Router 2. If the link between Router 1 and Router 2 fails, traffic from LSP A is quickly
switched to the bypass LSP generated by link protection.
Figure 22: Link Protection Creating a Bypass LSP for the Protected
Interface
Although LSPs traversing an interface can be configured to take advantage of link
protection, it is important to note that it is specifically the interface that benefits from
link protection. If link protection is enabled on an interface but not on a particular LSP
traversing that interface, then if the interface fails, that LSP will also fail.
NOTE: Link protection does not work on unnumbered interfaces.
To protect traffic over the entire route taken by an LSP, you should configure fast reroute.
For more information, see “Configuring Fast Reroute” on page 134.
The following sections provide more information on link protection:
•
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Fast Reroute, Node Protection, and Link Protection on page 347
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•
Multiple Bypass LSPs on page 349
Multiple Bypass LSPs
By default, link protection relies on a single bypass LSP to provide path protection for an
interface. However, you can also specify multiple bypass LSPs to provide link protection
for an interface. You can individually configure each of these bypass LSPs or create a
single configuration for all of the bypass LSPs. If you do not configure the bypass LSPs
individually, they all share the same path and bandwidth constraints.
The following algorithm describes how and when an additional bypass LSP is activated
for an LSP:
1.
If any currently active bypass can satisfy the requirements of the LSP (bandwidth,
link protection, or node-link protection), the traffic is directed to that bypass.
2. If no active bypass LSP is available, scan through the manual bypass LSPs in first-in,
first-out (FIFO) order, skipping those that are already active (each manual bypass
can only be activated once). The first inactive manual bypass that can satisfy the
requirements is activated and traffic is directed to that bypass.
3. If no manual bypass LSPs are available and if the max-bypasses statement activates
multiple bypass LSPs for link protection, determine whether an automatically
configured bypass LSP can satisfy the requirements. If an automatically configured
bypass LSP is available and if the total number of active automatically configured
bypass LSPs does not exceed the maximum bypass LSP limit (configured with the
max-bypasses statement), activate another bypass LSP.
For information about how to configure multiple bypass LSPs for link protection, see
“Configuring Bypass LSPs” on page 367.
Node Protection
Node protection extends the capabilities of link protection. Link protection helps to ensure
that traffic going over a specific interface to a neighboring router can continue to reach
this router if that interface fails. Node protection ensures that traffic from an LSP traversing
a neighboring router can continue to reach its destination even if the neighboring router
fails.
When you enable node protection for an LSP, you must also enable link protection. Once
enabled, node protection and link protection establish the following types of bypass
LSPs:
•
Next-hop bypass LSP—Provides an alternate route for an LSP to reach a neighboring
router. This type of bypass LSP is established when you enable either node protection
or link protection.
•
Next-next-hop bypass LSP—Provides an alternate route for an LSP to get around a
neighboring router en route to the destination router. This type of bypass LSP is
established exclusively when node protection is configured. If a next-next-hop bypass
LSP cannot be created, an attempt is made to signal a next-hop bypass LSP.
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In Figure 23 on page 350, node protection is enabled on Interface B on Router 1. Node
protection is also enabled on LSP A, an LSP that traverses the link transiting Router 1,
Router 2, and Router 3. If Router 2 suffers a hardware or software failure, traffic from LSP
A is switched to the next-next-hop bypass LSP generated by node protection.
Figure 23: Node Protection Creating a Next-Next-Hop Bypass LSP
1
2
3
Next-Next-Hop Bypass LSP for Interface B
LSP A
g017083
Interface B
LSP A
The time needed by node protection to switch traffic to a next-next-hop bypass LSP can
be significantly longer than the time needed by link protection to switch traffic to a
next-hop bypass LSP. Link protection relies on a hardware mechanism to detect a link
failure, allowing it to quickly switch traffic to a next-hop bypass LSP.
Node failures are often due to software problems on the node router. Node protection
relies on the receipt of hello messages from a neighboring router to determine whether
it is still functioning. The time it takes node protection to divert traffic partly depends on
how often the node router sends hello messages and how long it takes the node-protected
router to react to having not received a hello message. However, once the failure is
detected, traffic can be quickly diverted to the next-next-hop bypass LSP.
NOTE:
Node protection provides traffic protection in the event of an error or
interruption of the physical link between two routers. It does not provide
protection in the event of control plane errors. The following provides an
example of a control plane error:
Related
Documentation
•
•
A transit router changes the label of a packet due to a control plane error.
•
When the ingress router receives the packet, it considers the label change
to be a catastrophic event and deletes both the primary LSP and the
associated bypass LSP.
Configuring Node Protection or Link Protection for LSPs on page 364
RSVP Graceful Restart
RSVP graceful restart allows a router undergoing a restart to inform its adjacent neighbors
of its condition. The restarting router requests a grace period from the neighbor or peer,
which can then cooperate with the restarting router. The restarting router can still forward
MPLS traffic during the restart period; convergence in the network is not disrupted. The
restart is not visible to the rest of the network, and the restarting router is not removed
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from the network topology. RSVP graceful restart can be enabled on both transit routers
and ingress routers. It is available for both point-to-point LSPs and point-to-multipoint
LSPs.
RSVP graceful restart is described in the following sections:
•
RSVP Graceful Restart Standard on page 351
•
RSVP Graceful Restart Terminology on page 351
•
RSVP Graceful Restart Operation on page 351
•
Processing the Restart Cap Object on page 352
RSVP Graceful Restart Standard
RSVP graceful restart is described in RFC 3473, Generalized Multi-Protocol Label Switching
(GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE)
Extensions (only Section 9, “Fault Handling”).
RSVP Graceful Restart Terminology
R
Recovery time
(in milliseconds)
Applies only when the control channel is up (the hello exchange is complete) before the restart
time. Applies only to nodal faults.
When a graceful restart is in progress, the time left to complete a recovery is advertised. At
other times, this value is zero. The maximum advertised recovery time is 2 minutes (120,000
milliseconds).
During the recovery time, a restarting node attempts to recover its lost states with assistance
from its neighbors. The neighbor of the restarting node must send the path messages with the
recovery labels to the restarting node within a period of one-half the recovery time. The
restarting node considers its graceful restart complete after its advertised recovery time.
Restart time
The default value is 60,000 milliseconds (1 minute). The restart time is advertised in the hello
(in milliseconds)
message. The time indicates how long a neighbor should wait to receive a hello message from
a restarting router before declaring that router dead and purging states.
The Junos OS can override a neighbor’s advertised restart time if the time is greater than
one-third the local restart time. For example, given the default restart time of 60 seconds, a
router would wait 20 seconds or less to receive a hello message from a restarting neighbor. If
the restart time is zero, the restarting neighbor can immediately be declared dead.
RSVP Graceful Restart Operation
For RSVP graceful restart to function, the feature must be enabled on the global routing
instance. RSVP graceful restart can be disabled at the protocol level (for RSVP alone)
or at the global level for all protocols.
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RSVP graceful restart requires the following of a restarting router and the router’s
neighbors:
•
For the restarting router, RSVP graceful restart attempts to maintain the routes installed
by RSVP and the allocated labels, so that traffic continues to be forwarded without
disruption. RSVP graceful restart is done quickly enough to reduce or eliminate the
impact on neighboring nodes.
•
The neighboring routers must have RSVP graceful restart helper mode enabled, thus
allowing them to assist a router attempting to restart RSVP.
An object called Restart Cap that is sent in RSVP hello messages advertises a node’s
restart capability. The neighboring node sends a Recover Label object to the restarting
node to recover its forwarding state. This object is essentially the old label that the
restarting node advertised before the node went down.
The following lists the RSVP graceful restart behaviors, which vary depending on the
configuration and on which features are enabled:
•
If you disable helper mode, the Junos OS does not attempt to help a neighbor restart
RSVP. Any information that arrives with a Restart Cap object from a neighbor is ignored.
•
When you enable graceful restart under the routing instance configuration, the router
can restart gracefully with the help of its neighbors. RSVP advertises a Restart Cap
object (RSVP RESTART) in hello messages in which restart and recovery times are
specified (neither value is 0).
•
If you explicitly disable RSVP graceful restart under the [protocols rsvp] hierarchy level,
the Restart Cap object is advertised with restart and recovery times specified as 0. The
restart of neighboring routers is supported (unless helper mode is disabled), but the
router itself does not preserve the RSVP forwarding state and cannot recover its control
state.
•
If after a restart RSVP realizes that no forwarding state has been preserved, the Restart
Cap object is advertised with restart and recovery times specified as 0.
•
If graceful restart and helper mode are disabled, RSVP graceful restart is completely
disabled. The router neither recognizes nor advertises the RSVP graceful restart objects.
You cannot explicitly configure values for the restart and recovery times.
Unlike other protocols, there is no way for RSVP to determine that it has completed a
restart procedure, other than a fixed timeout. All RSVP graceful restart procedures are
timer-based. A show rsvp version command might indicate that the restart is still in
progress even if all RSVP sessions are back up and the routes are restored.
Processing the Restart Cap Object
The following assumptions are made about a neighbor based on the Restart Cap object
(assuming that a control channel failure can be distinguished unambiguously from a
node restart):
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•
A neighbor that does not advertise the Restart Cap object in its hello messages cannot
assist a router with state or label recovery, nor can it perform an RSVP graceful restart.
•
After a restart, a neighbor advertising a Restart Cap object with a restart time equal to
any value and a recovery time equal to 0 has not preserved its forwarding state. When
a recovery time equals 0, the neighbor is considered dead and any states related to
this neighbor are purged, regardless of the value of the restart time.
•
After a restart, a neighbor advertising its recovery time with a value other than 0 can
keep or has kept the forwarding state. If the local router is helping its neighbor with
restart or recovery procedures, it sends a Recover Label object to this neighbor.
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CHAPTER 12
RSVP Configuration Guidelines
This chapter describes how to configure RSVP and discusses the following configuration
tasks:
•
Minimum RSVP Configuration on page 355
•
Configuring RSVP and MPLS on page 356
•
Configuring RSVP Interfaces on page 357
•
Configuring RSVP Node ID Hellos on page 363
•
Configuring Hello Acknowledgments for Nonsession RSVP Neighbors on page 363
•
Configuring Node Protection or Link Protection for LSPs on page 364
•
Switching LSPs Away from a Network Node on page 365
•
Configuring Inter-AS Node and Link Protection on page 366
•
Configuring Link Protection on Interfaces Used by LSPs on page 366
•
Configuring RSVP Setup Protection on page 374
•
Configuring RSVP Graceful Restart on page 374
•
Configuring Load Balancing Across RSVP LSPs on page 376
•
Configuring RSVP Automatic Mesh on page 377
•
Configuring Timers for RSVP Refresh Messages on page 378
•
Preempting RSVP Sessions on page 379
•
Configuring MTU Signaling in RSVP on page 380
•
Configuring RSVP to Pop the Label on the Ultimate-Hop Router on page 381
•
Disabling Adjacency Down and Neighbor Down Notification in IS-IS and
OSPF on page 382
•
Enabling Ultimate-Hop Popping on Point-to-Multipoint LSPs on page 382
•
Tracing RSVP Protocol Traffic on page 383
Minimum RSVP Configuration
To enable RSVP on a single interface, include the rsvp statement and specify the interface
using the interface statement. This is the minimum RSVP configuration. All other RSVP
configuration statements are optional.
rsvp {
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interface interface-name;
}
You can include these statements at the following hierarchy levels:
•
[edit protocols]
•
[edit logical-systems logical-system-name protocols]
To enable RSVP on all interfaces, substitute all for the interface-name variable.
If you have configured interface properties on a group of interfaces and want to disable
RSVP on one of the interfaces, include the disable statement:
interface interface-name {
disable;
}
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp interface interface-name ]
•
[edit logical-systems logical-system-name protocols rsvp interface interface-name ]
Configuring RSVP and MPLS
The primary purpose of the Junos RSVP software is to support dynamic signaling within
label-switched paths (LSPs). When you enable both MPLS and RSVP on a router, MPLS
becomes a client of RSVP. No additional configuration is required to bind MPLS and
RSVP.
You can configure MPLS to set up signaled paths by using the label-switched-path
statement at the [edit protocols mpls] hierarchy level. Each LSP translates into a request
for RSVP to initiate an RSVP session. This request is passed through the internal interface
between label switching and RSVP. After examining the request information, checking
RSVP states, and checking the local routing tables, RSVP initiates one session for each
LSP. The session is sourced from the local router and is destined for the target of the
LSP.
When an RSVP session is successfully created, the LSP is set up along the paths created
by the RSVP session. If the RSVP session is unsuccessful, RSVP notifies MPLS of its
status. It is up to MPLS to initiate backup paths or continue retrying the initial path.
To pass label-switching signaling information, RSVP supports four additional objects:
Label Request object, Label object, Explicit Route object, and Record Route object. For
an LSP to be set up successfully, all routers along the path must support MPLS, RSVP,
and the four objects. Of the four objects, the Record Route object is not mandatory.
To configure MPLS and make it a client of RSVP, do the following:
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•
Enable MPLS on all routers that will participate in the label switching (this is, on all
routers that might be part of a label-switching path).
•
Enable RSVP on all routers and on all router interfaces that form the LSP.
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Chapter 12: RSVP Configuration Guidelines
•
Configure the routers at the beginning of the LSP.
Example: Configuring RSVP and MPLS
The following shows a sample configuration for a router at the beginning of an LSP:
[edit]
protocols {
mpls {
label-switched-path sf-to-london {
to 192.168.1.4;
}
}
rsvp {
interface so-0/0/0;
}
}
The following shows a sample configuration for all the other routers that form the LSP:
[edit]
protocols {
mpls {
interface so-0/0/0;
}
rsvp {
interface so-0/0/0;
}
}
Configuring RSVP Interfaces
The following sections describe how to configure RSVP interfaces:
•
Configuring RSVP Refresh Reduction on page 357
•
Configuring the RSVP Hello Interval on page 360
•
Configuring RSVP Authentication on page 360
•
Configuring the Bandwidth Subscription for Class Types on page 361
•
Configuring the RSVP Update Threshold on an Interface on page 361
•
Configuring RSVP for Unnumbered Interfaces on page 362
Configuring RSVP Refresh Reduction
You can configure RSVP refresh reduction on each interface by including the following
statements in the interface configuration:
•
aggregate—Enable all RSVP refresh reduction features: RSVP message bundling, RSVP
message ID, reliable message delivery, and summary refresh.
•
no-aggregate—Disable RSVP message bundling and summary refresh.
•
reliable—Enable RSVP message ID and reliable message delivery.
•
no-reliable—Disable RSVP message ID, reliable message delivery, and summary refresh.
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For more information on RSVP refresh reduction, see “RSVP Refresh Reduction” on
page 344.
Table 8 on page 358 lists various combinations of the RSVP refresh reduction configuration
statements and how they alter the behavior of the Junos OS. The table describes only
the expected behavior based on the configuration on the router. The actual behavior is
dictated not only by the local configuration on this router, but also on the refresh reduction
capabilities of its RSVP neighbors. Note that by configuring the aggregate statement,
you enable all RSVP refresh reduction features, including reliable message delivery.
Table 8: RSVP Refresh Reduction Behavior
Configuration Statement
Send Capability
Receive Capability
aggregate or aggregate and
reliable
RR bit = 1BundleMessage ID
(Path/Resv messages)Ack/Nack
(all messages)Summary Refresh
BundleAck/Nack (all
messages)Summary
Refresh
aggregate and no-reliable
RR bit = 1BundleAck/Nack (all
messages)
BundleMessage ID (all
messages)
reliable or reliable and
no-aggregate
RR bit = 0Message ID (Path/Resv
messages)Ack/Nack (all
messages)
BundleMessage ID (all
messages)Ack/Nack
The send capability shown in Table 8 on page 358 lists the RSVP messages and objects
related to RSVP refresh reduction that the router is capable of sending. This does not
mean that all these messages are exchanged between this router and a neighbor. For
example, if the router is configured with the aggregate statement, but RSVP refresh
reduction is not enabled on its neighbor, then no Summary Refresh message is sent to
this neighbor even though the router is capable of sending it.
The receive capability shown in Table 8 on page 358 lists the messages and objects related
to RSVP refresh reduction that the router is capable of receiving and processing without
generating any errors or resulting in error conditions.
If the no-reliable statement is configured on the router (reliable message delivery is
disabled), the router accepts RSVP messages that include the Message ID object but
ignore the Message ID object and continue performing standard message processing.
No error is generated in this case, and RSVP operates normally.
However, not all combinations between two neighbors with different refresh reduction
capabilities function correctly. For example, a router is configured with either the aggregate
statement and no-reliable statement or with the reliable and no-aggregate statements.
If an RSVP neighbor sends a Summary Refresh object to this router, no error is generated,
but the Summary Refresh object cannot be processed. Consequently, RSVP states can
time out on this router if the neighbor is relying only on Summary Refresh to refresh those
RSVP states.
We recommend, unless there are specific requirements, that you configure RSVP refresh
reduction in a similar manner on each RSVP neighbor.
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To enable all RSVP refresh reduction features on an interface, include the aggregate
statement:
aggregate;
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp interface interface-name]
•
[edit logical-systems logical-system-name protocols rsvp interface interface-name]
To disable RSVP message bundling and summary refresh, include the no-aggregate
statement:
no-aggregate;
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp interface interface-name]
•
[edit logical-systems logical-system-name protocols rsvp interface interface-name]
To enable RSVP message ID and reliable message delivery on an interface, include the
reliable statement:
reliable;
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp interface interface-name]
•
[edit logical-systems logical-system-name protocols rsvp interface interface-name]
To disable RSVP message ID, reliable message delivery, and summary refresh, include
the no-reliable statement:
no-reliable;
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp interface interface-name]
•
[edit logical-systems logical-system-name protocols rsvp interface interface-name]
Determining the Refresh Reduction Capability of RSVP Neighbors
To determine the RSVP refresh reduction capability of an RSVP neighbor, you need the
following information:
•
The RR bit advertised by the neighbor
•
The local configuration of RSVP refresh reduction
•
The actual RSVP messages received from the neighbor
To obtain this information, you can issue a show rsvp neighbor detail command. Sample
output follows:
user@host> show rsvp neighbor detail
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RSVP neighbor: 6 learned
Address: 192.168.224.178 via: fxp1.0 status: Up
Last changed time: 10:06, Idle: 5 sec, Up cnt: 1, Down cnt: 0
Message received: 36
Hello: sent 69, received: 69, interval: 9 sec
Remote instance: 0x60b8feba, Local instance: 0x74bc7a8d
Refresh reduction: not operational
Address: 192.168.224.186 via: fxp2.0 status: Down
Last changed time: 10:17, Idle: 40 sec, Up cnt: 0, Down cnt: 0
Message received: 6
Hello: sent 20, received: 0, interval: 9 sec
Remote instance: 0x0, Local instance: 0x2ae1b339
Refresh reduction: incomplete
Remote end: disabled, Ack-extension: enabled
Address: 192.168.224.188 via: fxp2.0 status: Up
Last changed time: 4:15, Idle: 0 sec, Up cnt: 1, Down cnt: 0
Message received: 55
Hello: sent 47, received: 31, interval: 9 sec
Remote instance: 0x6436a35b, Local instance: 0x663849f0
Refresh reduction: operational
Remote end: enabled, Ack-extension: enabled
For more information on the show rsvp neighbor detail command, see the Junos OS Routing
Protocols and Policies Command Reference.
Configuring the RSVP Hello Interval
RSVP monitors the status of the interior gateway protocol (IGP) (IS-IS or OSPF) neighbors
and relies on the IGP protocols to detect when a node fails. If an IGP protocol declares
a neighbor down (because hello packets are no longer being received), RSVP also brings
down that neighbor. However, the IGP protocols and RSVP still act independently when
bringing a neighbor up.
For Juniper Networks routers, configuring a shorter or longer RSVP hello interval has no
impact on whether or not an RSVP session is brought down. RSVP sessions are kept up
even if RSVP hello packets are no longer being received. RSVP sessions are maintained
until either the router stops receiving IGP hello packets or the RSVP Path and Resv
messages time out.
However, the RSVP hello interval might impact when another vendor’s equipment brings
down an RSVP session. For example, a neighboring non-Juniper Networks router might
be configured to monitor RSVP hello packets.
To modify how often RSVP sends hello packets, include the hello-interval statement:
hello-interval seconds;
For a list of hierarchy levels at which you can include this statement, see the statement
summary section.
Configuring RSVP Authentication
All RSVP protocol exchanges can be authenticated to guarantee that only trusted
neighbors participate in setting up reservations. By default, RSVP authentication is
disabled.
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RSVP authentication uses a Hashed Message Authentication Code (HMAC)-MD5
message-based digest. This scheme produces a message digest based on a secret
authentication key and the message contents. (The message contents also include a
sequence number.) The computed digest is transmitted with RSVP messages. Once you
have configured authentication, all received and transmitted RSVP messages with all
neighbors are authenticated on this interface.
MD5 authentication provides protection against forgery and message modification. It
also can prevent replay attacks. However, it does not provide confidentiality, because
all messages are sent in clear text.
By default, authentication is disabled. To enable authentication, configure a key on each
interface by including the authentication-key statement:
authentication-key key;
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp interface interface-name]
•
[edit logical-systems logical-system-name protocols rsvp interface interface-name]
Configuring the Bandwidth Subscription for Class Types
By default, RSVP allows 100 percent of the bandwidth for a class type to be used for
RSVP reservations. When you oversubscribe a class type for a multiclass LSP, the
aggregate demand of all RSVP sessions is allowed to exceed the actual capacity of the
class type.
For detailed instructions on how to configure the bandwidth subscription for class types,
see “Configuring the Bandwidth Subscription Percentage for LSPs” on page 183.
Configuring the RSVP Update Threshold on an Interface
The interior gateway protocols (IGPs) maintain the traffic engineering database, but the
current available bandwidth on the traffic engineering database links originates from
RSVP. When a link’s bandwidth changes, RSVP informs the IGPs, which can then update
the traffic engineering database and forward the new bandwidth information to all
network nodes. The network nodes then know how much bandwidth is available on the
traffic engineering database link (local or remote), and CSPF can correctly compute the
paths.
However, IGP updates can consume excessive system resources. Depending on the
number of nodes in a network, it might not be desirable to perform an IGP update for
small changes in bandwidth. By configuring the update-threshold statement at the [edit
protocols rsvp] hierarchy level, you can adjust the threshold at which a change in the
reserved bandwidth triggers an IGP update.
You can configure a value of from 1 percent through 20 percent (the default is 10 percent)
for when to trigger an IGP update. If the change in the reserved bandwidth is greater than
or equal to the configured threshold percentage of the static bandwidth on that interface,
then an IGP update occurs. For example, if you have configured the update-threshold
statement to be 15 percent and the router discovers that the reserved bandwidth on a
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link has changed by 10 percent of the link bandwidth, RSVP does not trigger an IGP update.
However, if the reserved bandwidth on a link changes by 20 percent of the link bandwidth,
RSVP triggers an IGP update.
To adjust the threshold at which a change in the reserved bandwidth triggers an IGP
update, include the update-threshold statement:
update-threshold percentage;
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp interface interface-name]
•
[edit logical-systems logical-system-name protocols rsvp interface interface-name]
Because of the update threshold, it is possible for Constrained Shortest Path First (CSPF)
to compute a path using outdated traffic engineering database bandwidth information
on a link. If RSVP attempts to establish an LSP over that path, it might find that there is
insufficient bandwidth on that link. When this happens, RSVP triggers an IGP traffic
engineering database update, flooding the updated bandwidth information on the
network. CSPF can then recompute the path by using the updated bandwidth information,
and attempt to find a different path, avoiding the congested link. Note that this
functionality is the default and does not need any additional configuration.
You can configure the rsvp-error-hold-time statement at the [edit protocols mpls] hierarchy
level or the [edit logical-systems logical-system-name protocols mpls] hierarchy level to
improve the accuracy of the traffic engineering database (including the accuracy of
bandwidth estimates for LSPs) using information provided by PathErr messages. See
“Improving Traffic Engineering Database Accuracy with RSVP PathErr Messages” on
page 63.
Configuring RSVP for Unnumbered Interfaces
The Junos OS supports RSVP traffic engineering over unnumbered interfaces. Traffic
engineering information about unnumbered links is carried in the IGP traffic engineering
extensions for OSPF and IS-IS as described in RFC 4203, OSPF Extensions in Support of
Generalized Multi-Protocol Label Switching (GMPLS), and RFC 4205, Intermediate System
to Intermediate System (IS-IS) Extensions in Support of Generalized Multi-Protocol Label
Switching (GMPLS). Unnumbered links can also be specified in the MPLS traffic
engineering signaling as described in RFC 3477, Signalling Unnumbered Links in Resource
ReSerVation Protocol - Traffic Engineering (RSVP-TE). This feature allows you avoid
having to configure IP addresses for each interface participating in the RSVP-signaled
network.
To configure RSVP for unnumbered interfaces, you must configure the router with a
router ID using the router-id statement specified at the [edit routing-options] hierarchy
level. The router ID must be available for routing (you can typically use the loopback
address). The RSVP control messages for the unnumbered links are sent using the router
ID address (rather than a randomly selected address).
To configure link protection and fast reroute on a router with unnumbered interfaces
enabled, you must configure at least two addresses. We recommend that you configure
a secondary interface on the loopback in addition to configuring the router ID.
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Configuring RSVP Node ID Hellos
You can configure node-ID based RSVP hellos to ensure that Juniper Networks routers
can interoperate with the equipment of other vendors. By default, the Junos OS uses
interface-based RSVP hellos. Node-ID based RSVP hellos are specified in RFC 4558,
Node-ID Based Resource Reservation Protocol (RSVP) Hello: A Clarification Statement.
RSVP node-ID hellos are useful if you have configured BFD to detect problems over RSVP
interfaces, allowing you to disable interface-hellos for these interfaces. You can also use
node-ID hellos for graceful-restart procedures.
Node-ID hellos can be enabled globally for all RSVP neighbors. By default, node-ID hello
support is disabled. If you have not enabled RSVP node IDs on the router, the Junos OS
does not accept any node-ID hello packets.
To enable RSVP node-ID hellos globally on the router, include the node-hello statement:
node-hello;
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp]
•
[edit logical-systems logical-systems-name protocols rsvp]
You can also explicitly disable RSVP interface hellos globally. This type of configuration
might be necessary in networks where the Juniper Networks router has numerous RSVP
connections with equipment from other vendors. However, if you disable RSVP interface
hellos globally, you can also configure a hello interval on an RSVP interface using the
hello-interval statement. This configuration disables RSVP interface hellos globally, but
enables RSVP interface hellos on the specified interface (the RSVP interface you configure
the hello-interval statement on). This configuration might be necessary in a heterogeneous
network in which some devices support RSVP node ID hellos and other devices support
RSVP interface hellos.
To disable RSVP interface hellos globally on the router, include the no-interface-hello
statement:
no-interface-hello;
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp]
•
[edit logical-systems logical-systems-name protocols rsvp]
Configuring Hello Acknowledgments for Nonsession RSVP Neighbors
The hello-acknowledgements statement controls the hello acknowledgment behavior
between RSVP neighbors regardless of whether or not they are in the same session.
Hello messages received from RSVP neighbors that are not part of a common RSVP
session are discarded. If you configure the hello-acknowledgements statement at the
[edit protocols rsvp] hierarchy level, hello messages from nonsession neighbors are
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acknowledged with a hello acknowledgment message. When hellos are received from
nonsession neighbors, an RSVP neighbor relationship is created and periodic hello
messages can now be received from the nonsession neighbor. The
hello-acknowledgements statement is disabled by default. Configuring this statement
allows RSVP-capable routers to be discovered using hello packets and verifies that the
interface is able to receive RSVP packets before sending any MPLS LSP setup messages.
Once you enable hello acknowledgments for nonsession RSVP neighbors, the router
continues to acknowledge hello messages from any nonsession RSVP neighbors unless
the interface itself goes down or you change the configuration. Interface-based neighbors
are not automatically aged out.
hello-acknowledgements;
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp]
•
[edit logical-systems logical-system-name protocols rsvp]
Configuring Node Protection or Link Protection for LSPs
When you configure node protection or link protection on a router, bypass LSPs are
created to the next-hop or next-next-hop routers for the LSPs traversing the router. You
must configure node protection or link protection for each LSP that you want protected.
To extend protection along the entire path used by an LSP, you must configure protection
on each router that the LSP traverses.
You can configure node protection or link protection for both static and dynamic LSPs.
To configure node protection on a router for a specified LSP, include the
node-link-protection statement:
node-link-protection;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name]
To configure link protection on a router for a specified LSP, include the link-protection
statement:
link-protection;
You can include this statement at the following hierarchy levels:
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•
[edit protocols mpls label-switched-path lsp-name]
•
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name]
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NOTE: To complete the configuration of node or link protection, you must
also configure link protection on all unidirectional RSVP interfaces that the
LSPs traverse, as described in “Configuring Link Protection on Interfaces Used
by LSPs” on page 366.
Switching LSPs Away from a Network Node
You can configure the router to switch active LSPs away from a network node using a
bypass LSP enabled for an interface. This feature might be used to maintain active
networks when a device needs to be replaced without interrupting traffic transiting the
network. The LSPs can be either static or dynamic.
1.
You first need to configure either link or node protection for the traffic that needs to
pass around the network device you intend to disable. To function properly, the bypass
LSP must use a different logical interface than the protected LSP.
2. To prepare the router to begin switching traffic away from a network node, configure
the always-mark-connection-protection-tlv statement:
always-mark-connection-protection-tlv;
The router then marks all OAM traffic transiting this interface in preparation for
switching the traffic to an alternate path based on the OAM functionality.
You can configure this statement at the following hierarchy levels:
•
[edit protocols mpls interface interface-name]
•
[edit logical-systems logical-system-name protocols mpls interface interface-name]
3. You then need to configure the switch-away-lsps statement to switch the traffic from
the protected LSP to the bypass LSP, effectively bypassing the default downstream
network device. The actual link itself is not brought down by this configuration.
To configure the router to switch traffic away from a network node, configure the
switch-away-lsps statement:
switch-away-lsps;
You can configure this statement at the following hierarchy levels:
•
[edit protocols mpls interface interface-name]
•
[edit logical-systems logical-system-name protocols mpls interface interface-name]
Note the following limitations related to switching active LSPs away from a network
node:
•
The switch-away feature is supported on MX Series routers only.
•
The switch-away feature is not supported for switching traffic from primary
point-to-multipoint LSPs to bypass point-to-multipoint LSPs. If you configure the
switch-away-lsps statement for a point-to-multipoint LSP, traffic is not switched to
the bypass point-to-multipoint LSP.
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Related
Documentation
•
If you configure the switch-away feature on an interface along the path of a dynamic
LSP, new dynamic LSPs cannot be established over that path. The switch-away feature
prevents the make-before-break behavior of RSVP-signaled LSPs. The
make-before-break behavior normally causes the router to first attempt to re-signal
a dynamic LSP before tearing down the original.
•
Configuring Node Protection or Link Protection for LSPs on page 364
Configuring Inter-AS Node and Link Protection
To interoperate with other vendors’ equipment, the Junos OS supports the record route
object (RRO) node ID subobject for use in inter-AS link and node protection configurations.
The RRO node ID subobject is defined in RFC 4561, Definition of a Record Route Object
(RRO) Node-Id Sub-Object. This functionality is enabled by default in Junos OS Release 9.4
and later.
If you have Juniper Networks routers running Junos OS Release 9.4 and later releases in
the same MPLS-TE network as routers running Junos OS Release 8.4 and earlier releases,
you might need to disable the RRO node ID subobject by configuring the
no-node-id-subobject statement:
no-node-id-subobject;
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp]
•
[edit logical-systems logical-system-name protocols rsvp]
Configuring Link Protection on Interfaces Used by LSPs
When you configure node protection or link protection on a router for LSPs as described
in “Configuring Node Protection or Link Protection for LSPs” on page 364, you also must
configure the link-protection statement on the RSVP interfaces used by the LSPs.
To configure link protection on the interfaces used by the LSPs, include the link-protection
statement:
link-protection {
disable;
admin-group
exclude group-names;
include-all group-names;
include-any group-names;
}
bandwidth bps;
bypass bypass-name {
bandwidth bps;
description text;
hop-limit number;
no-cspf;
path address <strict | loose>;
priority setup-priority reservation-priority;
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to address;
}
class-of-service cos-value;
hop-limit number;
max-bypasses number;
no-cspf;
no-node-protection;
optimize-timer seconds;
path address <strict | loose>;
priority setup-priority reservation-priority;
subscription percent {
ct0 percent;
ct1 percent;
ct2 percent;
ct3 percent;
}
}
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp interface interface-name]
•
[edit logical-systems logical-system-name protocols rsvp interface interface-name]
All the statements under link-protection are optional.
The following sections describe how to configure link protection:
•
Configuring Bypass LSPs on page 367
•
Configuring Administrative Groups for Bypass LSPs on page 368
•
Configuring the Bandwidth for Bypass LSPs on page 369
•
Configuring Class of Service for Bypass LSPs on page 369
•
Configuring the Hop Limit for Bypass LSPs on page 370
•
Configuring the Maximum Number of Bypass LSPs on page 370
•
Disabling CSPF for Bypass LSPs on page 371
•
Disabling Node Protection for Bypass LSPs on page 371
•
Configuring the Optimization Interval for Bypass LSPs on page 371
•
Configuring an Explicit Path for Bypass LSPs on page 372
•
Configuring the Amount of Bandwidth Subscribed for Bypass LSPs on page 373
•
Configuring Priority and Preemption for Bypass LSPs on page 373
Configuring Bypass LSPs
You can configure specific bandwidth and path constraints for a bypass LSP. You can
also individually configure each bypass LSP generated when you enable multiple bypass
LSPs. If you do not configure the bypass LSPs individually, they all share the same path
and bandwidth constraints (if any).
If you specify the bandwidth, hop-limit, and path statements for the bypass LSP, these
values take precedence over the values configured at the [edit protocols rsvp interface
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interface-name link-protection] hierarchy level. The other attributes (subscription,
no-node-protection, and optimize-timer) are inherited from the general constraints.
To configure a bypass LSP, specify a name for the bypass LSP using the bypass statement.
The name can be up to 64 characters in length.
bypass bypass-name {
bandwidth bps;
description text;
class-of-service cos-value;
hop-limit number;
no-cspf;
path address <strict | loose>;
priority setup-priority reservation-priority;
to address;
}
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp interface interface-name link-protection]
•
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection]
Configuring the Next-Hop or Next-Next-Hop Node Address for Bypass LSPs
If you configure a bypass LSP, you must also configure the to statement. The to statement
specifies the address for the interface of the immediate next-hop node (for link protection)
or the next-next-hop node (for node-link protection). The address specified determines
whether this is a link protection bypass or a node-link protection bypass. On multiaccess
networks (for example, a LAN), this address is also used to specify which next-hop node
is being protected.
Configuring Administrative Groups for Bypass LSPs
Administrative groups, also known as link coloring or resource class, are manually assigned
attributes that describe the “color” of links, such that links with the same color
conceptually belong to the same class. You can use administrative groups to implement
a variety of policy-based LSP setups. You can configure administrative groups for bypass
LSPs. For more information about configuring administrative groups, see “Configuring
Administrative Groups” on page 153.
To configure administrative groups for bypass LSPs, include the admin-group statement:
admin-group {
exclude group-names;
include-all group-names;
include-any group-names;
}
To configure an administrative group for all of the bypass LSPs, include the admin-group
statement at the following hierarchy levels:
•
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•
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection]
To configure an administrative groups for a specific bypass LSP, include the admin-group
statement at the following hierarchy levels:
•
[edit protocols rsvp interface interface-name link-protection bypass bypass-name]
•
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection bypass bypass-name]
Configuring the Bandwidth for Bypass LSPs
You can specify the amount of bandwidth allocated for automatically generated bypass
LSPs or you can individually specify the amount of bandwidth allocated for each LSP.
If you have enabled multiple bypass LSPs, this statement is required.
To specify the bandwidth allocation, include the bandwidth statement:
bandwidth bps;
For automatically generated bypass LSPs, include the bandwidth statement at the
following hierarchy levels:
•
[edit protocols rsvp interface interface-name link-protection]
•
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection]
For individually configured bypass LSPs, include the bandwidth statement at the following
hierarchy levels:
•
[edit protocols rsvp interface interface-name link-protection bypass bypass-name]
•
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection bypass bypass-name]
Configuring Class of Service for Bypass LSPs
You can specify the class-of-service value for bypass LSPs by including the class-of-service
statement:
class-of-service cos-value;
To apply a class-of-service value to all the automatically generated bypass LSPs, include
the class-of-service statement at the following hierarchy levels:
•
[edit protocols rsvp interface interface-name link-protection]
•
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection]
To configure a class-of-service value for a specific bypass LSPs, include the
class-of-service statement at the following hierarchy levels:
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•
[edit protocols rsvp interface interface-name link-protection bypass bypass-name]
•
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection bypass bypass-name]
Configuring the Hop Limit for Bypass LSPs
You can specify the maximum number of hops a bypass can traverse. By default, each
bypass can traverse a maximum of 255 hops (the ingress and egress routers count as
one hop each, so the minimum hop limit is two).
To configure the hop limit for bypass LSPs, include the hop-limit statement:
hop-limit number;
For automatically generated bypass LSPs, include the hop-limit statement at the following
hierarchy levels:
•
[edit protocols rsvp interface interface-name link-protection]
•
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection]
For individually configured bypass LSPs, include the hop-limit statement at the following
hierarchy levels:
•
[edit protocols rsvp interface interface-name link-protection bypass bypass-name]
•
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection bypass bypass-name]
Configuring the Maximum Number of Bypass LSPs
You can specify the maximum number of dynamic bypass LSPs permitted for protecting
an interface using the max-bypasses statement at the [edit protocols rsvp interface
interface-name link-protection] hierarchy level. When this statement is configured, multiple
bypasses for link protection are enabled. Call admission control (CAC) is also enabled.
By default, this option is disabled and only one bypass is enabled for each interface. You
can configure a value of between 0 through 99 for the max-bypasses statement.
Configuring a value of 0 prevents the creation of any dynamic bypass LSPs for the
interface. If you configure a value of 0 for the max-bypasses statement, you need to
configure one or more static bypass LSPs to enable link protection on the interface.
If you configure the max-bypasses statement, you must also configure the bandwidth
statement (discussed in “Configuring the Bandwidth for Bypass LSPs” on page 369).
To configure the maximum number of bypass LSPs for a protected interface, include the
max-bypasses statement:
max-bypasses number;
You can include this statement at the following hierarchy levels:
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•
[edit protocols rsvp interface interface-name link-protection]
•
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection]
Disabling CSPF for Bypass LSPs
Under certain circumstances, you might need to disable CSPF computation for bypass
LSPs and use the configured Explicit Route Object (ERO) if available. For example, a
bypass LSP might need to traverse multiple OSPF areas or IS-IS levels, preventing the
CSPF computation from working. To ensure that link and node protection function properly
in this case, you have to disable CSPF computation for the bypass LSP.
You can disable CSPF computation for all bypass LSPs or for specific bypass LSPs.
To disable CSPF computation for bypass LSPs, include the no-cspf statement:
no-cspf;
For a list of hierarchy levels where you can include this statement, see the statement
summary for this statement.
Disabling Node Protection for Bypass LSPs
You can disable node protection on the RSVP interface. Link protection remains active.
When this option is configured, the router can only initiate a next-hop bypass, not a
next-next-hop bypass.
To disable node protection for bypass LSPs, include the no-node-protection statement:
no-node-protection;
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp interface interface-name link-protection]
•
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection]
Configuring the Optimization Interval for Bypass LSPs
You can configure an optimization interval for bypass LSPs using the optimize-timer
statement. At the end of this interval, an optimization process is initiated that attempts
to either minimize the number of bypasses currently in use, minimize the total amount
of bandwidth reserved for all of the bypasses, or both. You can configure an optimization
interval from 1 through 65,535 seconds. A default value of 0 disables bypass LSP
optimization.
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When you configure the optimize-timer statement, bypass LSPs are reoptimized
automatically when you configure or change the configuration of any of the following:
•
Administrative group for a bypass LSP—The configuration for an administrative group
has been changed on a link along the path used by the bypass LSP. Configure an
administrative group using the admin-group statement at the [edit protocols rsvp
interface interface-name link-protection] hierarchy level.
•
Fate sharing group—The configuration for a fate sharing group has been changed.
Configure a fate sharing group using the group statement at the [edit routing-options
fate-sharing] hierarchy level.
•
IS-IS overload—The configuration for IS-IS overload has been changed on a router
along the path used by the bypass LSP. Configure IS-IS overload using the overload
statement at the [edit protocols isis] hierarchy level.
•
IGP metric—The IGP metric has been changed on a link along the path used by the
bypass LSP.
To configure the optimization interval for bypass LSPs, include the optimize-timer
statement:
optimize-timer seconds;
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp interface interface-name link-protection]
•
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection]
Configuring an Explicit Path for Bypass LSPs
By default, when you establish a bypass LSP to an adjacent neighbor, CSPF is used to
discover the least-cost path. The path statement allows you to configure an explicit path
(a sequence of strict or loose routes), giving you control over where and how the bypass
LSP is established. To configure an explicit path, include the path statement:
path address <strict | loose>;
For automatically generated bypass LSPs, include the path statement at the following
hierarchy levels:
•
[edit protocols rsvp interface interface-name link-protection]
•
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection]
For individually configured bypass LSPs, include the path statement at the following
hierarchy levels:
•
[edit protocols rsvp interface interface-name link-protection bypass bypass-name]
•
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection bypass bypass-name]
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Configuring the Amount of Bandwidth Subscribed for Bypass LSPs
You can configure the amount of bandwidth subscribed to bypass LSPs. You can configure
the bandwidth subscription for the whole bypass LSP or for each class type that might
traverse the bypass LSP. You can configure any value between 1 percent and 65,535
percent. By configuring a value less than 100 percent, you are undersubscribing the bypass
LSPs. By configuring a value greater than 100 percent, you are oversubscribing the bypass
LSPs.
The ability to oversubscribe the bandwidth for the bypass LSPs makes it possible to more
efficiently use network resources. You can configure the bandwidth for the bypass LSPs
based on the average network load as opposed to the peak load.
To configure the amount of bandwidth subscribed for bypass LSPs, include the
subscription statement:
subscription percentage {
ct0 percentage;
ct1 percentage;
ct2 percentage;
ct3 percentage;
}
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp interface interface-name link-protection]
•
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection]
Configuring Priority and Preemption for Bypass LSPs
When there is insufficient bandwidth to establish a more important LSP, you might want
to tear down a less important existing LSP to release the bandwidth. You do this by
preempting the existing LSP.
For more detailed information on configuring setup priority and reservation priority for
LSPs, see “Configuring Priority and Preemption for LSPs” on page 161.
To configure the bypass LSP’s priority and preemption properties, include the priority
statement:
priority setup-priority reservation-priority;
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
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Configuring RSVP Setup Protection
You can configure the facility-backup fast reroute mechanism to provide setup protection
for LSPs which are in the process of being signaled. Both point-to-point LSPs and
point-to-multipoint LSPs are supported. This feature is applicable in the following
scenario:
1.
A failed link or node is present on the strict explicit path of an LSP before the LSP is
signaled.
2. There is also a bypass LSP protecting the link or node.
3. RSVP signals the LSP through the bypass LSP. The LSP appears as if it was originally
set up along its primary path and then failed over to the bypass LSP because of the
link or node failure.
4. When the link or node has recovered, the LSP can be automatically reverted to the
primary path.
You should configure the setup-protection statement at the [edit protocols rsvp] on each
of the routers along the LSP path on which you want to enable LSP setup protection.
You should also configure IGP traffic engineering on all of the routers on the LSP path.
You can issue a show rsvp session command to determine whether or not the LSP has
setup protection enabled on a router acting as a point of local repair (PLR) or a merge
point.
To enable RSVP setup protection, include the setup-protection statement
setup-protection;
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp]
•
[edit logical-systems logical-system-name protocols rsvp]
Configuring RSVP Graceful Restart
The following RSVP graceful restart configurations are possible:
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•
Graceful restart and helper mode are both enabled (the default).
•
Graceful restart is enabled but helper mode is disabled. A router configured in this way
can restart gracefully, but cannot help a neighbor with its restart and recovery
procedures.
•
Graceful restart is disabled but helper mode is enabled. A router configured in this way
cannot restart gracefully, but can help a restarting neighbor.
•
Graceful restart and helper mode both are disabled. This configuration completely
disables RSVP graceful restart (including restart and recovery procedures and helper
mode). The router behaves like a router that does not support RSVP graceful restart.
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NOTE: In order to turn on RSVP graceful restart, you must set the global
graceful restart timer to at least 180 seconds.
The following sections describe how to configure RSVP graceful restart:
•
Enabling Graceful Restart for All Routing Protocols on page 375
•
Disabling Graceful Restart for RSVP on page 375
•
Disabling RSVP Helper Mode on page 375
•
Configuring the Maximum Helper Recovery Time on page 375
•
Configuring the Maximum Helper Restart Time on page 376
Enabling Graceful Restart for All Routing Protocols
To enable graceful restart for RSVP, you need to enable graceful restart for all the
protocols that support graceful restart on the router. For more information about graceful
restart, see the Junos OS Routing Protocols Configuration Guide.
To enable graceful restart on the router, include the graceful-restart statement:
graceful-restart;
You can include this statement at the following hierarchy levels:
•
[edit routing-options]
•
[edit logical-systems logical-system-name routing-options]
Disabling Graceful Restart for RSVP
By default, RSVP graceful restart and RSVP helper mode are enabled when you enable
graceful restart. However, you can disable one or both of these capabilities.
To disable RSVP graceful restart and recovery, include the disable statement at the [edit
protocols rsvp graceful-restart] hierarchy level:
disable;
Disabling RSVP Helper Mode
To disable RSVP helper mode, include the helper-disable statement at the [edit protocols
rsvp graceful-restart] hierarchy level:
helper-disable;
Configuring the Maximum Helper Recovery Time
To configure the amount of time the router retains the state of its RSVP neighbors while
they undergo a graceful restart, include the maximum-helper-recovery-time statement
at the [edit protocols rsvp graceful-restart] hierarchy level. This value is applied to all
neighboring routers, so it should be based on the time required by the slowest RSVP
neighbor to recover.
maximum-helper-recovery-time seconds;
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Configuring the Maximum Helper Restart Time
To configure the delay between when the router discovers that a neighboring router has
gone down and when it declares the neighbor down, include the
maximum-helper-restart-time statement at the [edit protocols rsvp graceful-restart]
hierarchy level. This value is applied to all neighboring routers, so it should be based on
the time required by the slowest RSVP neighbor to restart.
maximum-helper-restart-time seconds;
Configuring Load Balancing Across RSVP LSPs
By default, when you have configured several RSVP LSPs to the same egress router, the
LSP with the lowest metric is selected and carries all traffic. If all of the LSPs have the
same metric, one of the LSPs is selected at random and all traffic is forwarded over it.
Alternatively, you can load-balance traffic across all of the LSPs by enabling per-packet
load balancing.
To enable per-packet load balancing on an ingress LSP, configure the policy-statement
statement as follows:
[edit policy-options]
policy-statement policy-name {
then {
load-balance per-packet;
}
accept;
}
You then need to apply this statement as an export policy to the forwarding table. For
more information on how to configure the policy-statement statement, see the Junos OS
Routing Policy Configuration Guide.
Once per-packet load balancing is applied, traffic is distributed equally between the
LSPs (by default).
You need to configure per-packet load balancing if you want to enable PFE fast reroute.
To enable PFE fast reroute, include the policy-statement statement for per-packet load
balancing shown in this section in the configuration of each of the routers where a reroute
might take place. See also “Configuring Fast Reroute” on page 134.
You can also load-balance the traffic between the LSPs in proportion to the amount of
bandwidth configured for each LSP. This capability can better distribute traffic in networks
with asymmetric bandwidth capabilities across external links, since the configured
bandwidth of an LSP typically reflects the traffic capacity of that LSP.
To configure RSVP LSP load balancing, include the load-balance statement with the
bandwidth option:
load-balance {
bandwidth;
}
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You can configure this statement at the following hierarchy levels:
•
[edit protocols rsvp]
•
[edit logical-systems logical-system-name protocols rsvp]
Keep the following information in mind when you use the load-balance statement:
•
If you configure the load-balance statement, the behavior of currently running LSPs is
not altered. To force currently running LSPs to use the new behavior, you can issue a
clear mpls lsp command.
•
The load-balance statement only applies to ingress LSPs that have per-packet load
balancing enabled.
•
For Differentiated Services–aware traffic engineered LSPs, the bandwidth of an LSP
is calculated by summing the bandwidth of all of the class types.
Configuring RSVP Automatic Mesh
BGP and MPLS VPNs are based on a peer model. To add a new site to an existing VPN,
you need to configure the CE router at the new site and the PE router connected to the
CE router. You do not have to modify the configuration of all of the other PE routers
participating in the VPN. The PE routers automatically learn about the routes associated
with the new site (a process called automatic discovery).
The requirements are a bit different if you need to add a new PE router (as opposed to
a CE router) to the network. A BGP and MPLS VPN requires that the BGP session be fully
meshed and that there also be a full mesh of PE router-to-PE router MPLS LSPs between
all of the PE routers in the network. When you add a new PE router to the network, all of
the existing PE routers must be reconfigured to peer with the new PE router. Much of the
configuration effort can be reduced if you configure BGP route reflectors (mitigating the
full mesh requirement for BGP) and if you configure LDP as the signaling protocol for
MPLS.
However, if you need to add a new PE router to a network configured with a full mesh of
RSVP-signaled LSPs, you need to reconfigure each of the PE routers to have a peer
relationship with the new PE router. You can configure RSVP automatic mesh to address
this particular operational scenario. When you enable RSVP automatic mesh, RSVP LSPs
are dynamically created between a new PE router and the existing PE routers, eliminating
the need to reconfigure all of the PE routers manually. For dynamic tunnel creation to
function properly, BGP must be configured to exchange routes between all of the
participating PE routers. If two BGP peers did not exchange routes, it would not be possible
to configure a dynamic tunnel between them.
RSVP includes numerous capabilities that are not available in LDP, including fast reroute.
RSVP automatic mesh helps to reduce the operation and maintenance requirements for
RSVP, making it possible to deploy RSVP in larger and more complicated networks.
Every PE router can reach every other PE router in the network because this information
is distributed by the IGP. A PE router can set up an RSVP LSP to any other PE router in
the network so long as it knows that such an LSP is required. To build a full mesh of LSPs
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between the PE routers requires that each PE router know which of the other PE routers
make up the full mesh.
You can configure RSVP to establish LSPs automatically for any new PE router added
to a full mesh of LSPs. To enable this feature, you must configure the rsvp-te statement
on all of the PE routers in the full mesh.
NOTE: You cannot configure RSVP automatic mesh in conjunction with CCC.
CCC cannot use the dynamically generated tunnels.
To configure RSVP automatic mesh, include the rsvp-te statement:
rsvp-te {
destination-networks network-prefix;
label-switched-path-template {
default-template;
template-name;
}
}
You can configure these statements at the following hierarchy levels:
•
[edit routing-options dynamic-tunnels tunnel-name]
•
[edit logical-systems logical-system-name routing-options dynamic-tunnels tunnel-name]
You can configure the following optional statements for RSVP automatic mesh:
•
destination-networks—Specify the IP version 4 (IPv4) prefix range for the destination
network. Dynamic tunnels within the specified IPv4 prefix range are allowed to be
initiated.
•
label-switched-path-template—You can configure either the default template explicitly
using the default-template option or you can configure an LSP template of your own
using the template-name option. The LSP template acts as a model configuration for
all of the dynamically generated LSPs.
Configuring Timers for RSVP Refresh Messages
RSVP uses two related timing parameters:
•
refresh-time—The refresh time controls the interval between the generation of
successive refresh messages. The default value for the refresh time is 45 seconds. This
number is derived from the refresh-time statement’s default value of 30, multiplied by
a fixed value of 1.5. This computation differs from RFC 2205, which states that the
refresh time should be multiplied by a random value in the range from 0.5 through 1.5.
Refresh messages include path and Resv messages. Refresh messages are sent
periodically so that reservation states in neighboring nodes do not time out. Each path
and Resv message carries the refresh timer value, and the receiving node extracts this
value from the messages.
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•
keep-multiplier—The keep multiplier is a small, locally configured integer from 1 through
255. The default value is 3. It indicates the number of messages that can be lost before
a particular state is declared stale and must be deleted. The keep multiplier directly
affects the lifetime of an RSVP state.
To determine the lifetime of a reservation state, use the following formula:
lifetime = (keep-multiplier + 0.5) x (1.5 x refresh-time)
In the worst case, (keep-multiplier – 1) successive refresh messages must be lost before
a reservation state is deleted.
We do not recommend configuring a short RSVP hello timer. If quick discovery of a failed
neighbor is needed, configure short IGP (OSPF or IS-IS) hello timers.
By default, the refresh timer value is 30 seconds. To modify this value, include the
refresh-time statement:
refresh-time seconds;
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp]
•
[edit logical-systems logical-system-name protocols rsvp]
The default value of the keep multiplier is 3. To modify this value, include the
keep-multiplier statement:
keep-multiplier number;
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp]
•
[edit logical-systems logical-system-name protocols rsvp]
Preempting RSVP Sessions
Whenever bandwidth is insufficient to handle all RSVP sessions, you can control the
preemption of RSVP sessions. By default, an RSVP session is preempted only by a new
higher-priority session.
To always preempt a session when the bandwidth is insufficient, include the preemption
statement with the aggressive option:
preemption aggressive;
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp]
•
[edit logical-systems logical-system-name protocols rsvp]
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To disable RSVP session preemption, include the preemption statement with the disabled
option:
preemption disabled;
To return to the default (that is, preempt a session only for a new higher-priority session),
include the preemption statement with the normal option:
preemption normal;
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp]
•
[edit logical-systems logical-system-name protocols rsvp]
Configuring MTU Signaling in RSVP
To configure maximum transmission unit (MTU) signaling in RSVP, you need to configure
MPLS to allow IP packets to be fragmented before they are encapsulated in MPLS. You
also need to configure MTU signaling in RSVP. For troubleshooting purposes, you can
configure MTU signaling alone without enabling packet fragmentation.
To configure MTU signaling in RSVP, include the path-mtu statement:
path-mtu {
allow-fragmentation;
rsvp {
mtu-signaling;
}
}
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls]
The following sections describe how to enable packet fragmentation and MTU signaling
in RSVP:
•
Enabling MTU Signaling in RSVP on page 380
•
Enabling Packet Fragmentation on page 381
Enabling MTU Signaling in RSVP
To enable MTU signaling in RSVP, include the rsvp mtu-signaling statement:
rsvp mtu-signaling;
You can include this statement at the following hierarchy levels:
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•
[edit protocols mpls path-mtu]
•
[edit logical-systems logical-system-name protocols mpls path-mtu]
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Once you have committed the configuration, changes in the MTU signaling behavior for
RSVP take effect the next time the path is refreshed.
You can configure the mtu-signaling statement by itself at the [edit protocols mpls
path-mtu rsvp] hierarchy level. This can be useful for troubleshooting. If you configure
just the mtu-signaling statement, you can use the show rsvp session detail command to
determine what the smallest MTU is on an LSP. The show rsvp session detail command
displays the MTU value received and sent in the Adspec object.
Enabling Packet Fragmentation
To allow IP packets to be fragmented before they are encapsulated in MPLS, include the
allow-fragmentation statement:
allow-fragmentation;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls path-mtu]
•
[edit logical-systems logical-system-name protocols mpls path-mtu]
NOTE: Do not configure the allow-fragmentation statement alone. Always
configure it in conjunction with the mtu-signaling statement.
Configuring RSVP to Pop the Label on the Ultimate-Hop Router
You can control the label value advertised on the egress router of an LSP. The default
advertised label is label 3 (Implicit Null label). If label 3 is advertised, the penultimate-hop
router removes the label and sends the packet to the egress router. When ultimate-hop
popping is enabled, label 0 (IP version 4 [IPv4] Explicit Null label) is advertised.
Ultimate-hop popping ensures that any packets traversing an MPLS network include a
label.
To configure ultimate-hop popping for RSVP, include the explicit-null statement:
explicit-null;
You can include this statement at the following hierarchy levels:
•
[edit protocols mpls]
•
[edit logical-systems logical-system-name protocols mpls]
NOTE: Juniper Networks routers queue packets based on the incoming
label. Routers from other vendors might queue packets differently. Keep
this in mind when working with networks containing routers from multiple
vendors.
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For more information about labels, see “Label Description” on page 27 and “Label
Allocation” on page 28.
Disabling Adjacency Down and Neighbor Down Notification in IS-IS and OSPF
Whenever IS-IS is deactivated, the IS-IS adjacencies are brought down. IS-IS signals to
RSVP to bring down any RSVP neighbors associated with the IS-IS adjacencies, and this
further causes the associated LSPs signaled by RSVP to go down as well.
A similar process occurs whenever OSPF is deactivated. The OSPF neighbors are brought
down. OSPF signals to RSVP to bring down any of the RSVP neighbors associated with
the OSPF neighbors, and this further causes the associated LSPs signaled by RSVP to
go down as well.
If you need to migrate from IS-IS to OSPF or from OSPF to IS-IS, the IGP notification to
RSVP for an adjacency or neighbor down event needs to be ignored. Using the
no-adjacency-down-notification or no-neighbor-down-notification statements, you can
disable IS-IS adjacency down notification or OSPF neighbor down notification,
respectively, until the migration is complete. The network administrator is responsible
for configuring the statements before the migration, and then removing them from the
configuration afterward, so that IGP notification can function normally.
To disable adjacency down notification in IS-IS, include the
no-adjacency-down-notification statement:
no-adjacency-down-notification;
You can include this statement at the following hierarchy levels:
•
[edit protocols isis interface interface-name]
•
[edit logical-systems logical-system-name protocols isis interface interface-name]
To disable neighbor down notification in OSPF, include the no-neighbor-down-notification
statement:
no-neighbor-down-notification;
You can include this statement at the following hierarchy levels:
•
[edit protocols ospf area area-id interface interface-name]
•
[edit logical-systems logical-system-name protocols ospf area area-id interface
interface-name]
Enabling Ultimate-Hop Popping on Point-to-Multipoint LSPs
By default, for both point-to-point and point-to-multipoint LSPs, penultimate-hop
popping is used for MPLS traffic. MPLS labels are removed from packets on the router
just before the egress router of the LSP. The plain IP packets are then forwarded to the
egress router. For ultimate-hop popping, the egress router is responsible for both removing
the MPLS label and processing the plain IP packet.
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It can be beneficial to enable ultimate-hop popping on point-to-multipoint LSPs,
particularly when transit traffic is traversing the same egress device. If you enable
ultimate-hop popping, a single copy of traffic can be sent over the incoming link, saving
significant bandwidth. By default, ultimate-hop popping is disabled.
You enable ultimate-hop popping for point-to-multipoint LSPs by configuring the
tunnel-services statement. When you enable ultimate-hop popping, the Junos OS selects
one of the available virtual loopback tunnel (VT) interfaces to loop back the packets to
the PFE for IP forwarding. By default, the VT interface selection process is performed
automatically. Bandwidth admission control is used to limit the number of LSPs that can
be used on one VT interface. Once all the bandwidth is consumed on one interface, the
Junos OS selects another VT interface with sufficient bandwidth for admission control.
If an LSP requires more bandwidth than is available from any of the VT interfaces,
ultimate-hop popping cannot be enabled and penultimate-hop popping is enabled
instead.
You can explicitly configure which VT interfaces handle the RSVP traffic by including the
devices option for the tunnel-services statement. The devices option allows you to specify
which VT interfaces are to be used by RSVP. If you do not configure this option, all of the
VT interfaces available to the router can be used.
For ultimate-hop popping on point-to-multipoint LSPs to function properly, the egress
router must have a PIC that provides tunnel services, such as the tunnel services PIC or
the adaptive services PIC. Tunnel services are needed for popping the final MPLS label
and for returning packets for IP address lookups.
If you configure the tunnel-services statement on an operating router, only the behavior
of newly signaled LSPs changes. Existing LSPs are not affected. To force all existing LSPs
to use ultimate-hop popping, issue a clear mpls lsp command. Note that this causes all
of the MPLS LSPs on the router to be signaled again.
To enable ultimate-hop popping for the egress point-to-multipoint LSPs on a router,
configure the tunnel-services statement:
tunnel-services {
devices device-names;
}
You can configure this statement at the [edit protocols rsvp] hierarchy level.
To enable ultimate-hop popping for egress point-to-multipoint LSPs, you must also
configure the interface statement with the all option:
interface all;
You must configure this statement at the [edit protocols rsvp] hierarchy level.
Tracing RSVP Protocol Traffic
To trace RSVP protocol traffic, include the traceoptions statement:
traceoptions {
file filename <files number> <size size> <world-readable | no-world-readable>;
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flag flag <flag-modifier> <disable>;
}
You can include this statement at the following hierarchy levels:
•
[edit protocols rsvp]
•
[edit logical-systems logical-system-name protocols rsvp]
You can specify the following RSVP-specific flags in the RSVP traceoptions statement:
Use the file statement to specify the name of the file that receives the output of the
tracing operation. All files are placed in the directory /var/log. We recommend that you
place RSVP tracing output in the file rsvp-log.
•
all—All tracing operations.
•
error—All detected error conditions
•
event—RSVP-related events (helps to trace events related to RSVP graceful restart)
•
lmp—RSVP-Link Management Protocol (LMP) interactions
•
packets—All RSVP packets
•
path—All path messages
•
pathtear—PathTear messages
•
resv—Resv messages
•
resvtear—ResvTear messages
•
route—Routing information
•
state—Session state transitions
For general information about tracing and global tracing options, see the Junos OS Routing
Protocols Configuration Guide.
Examples: Tracing RSVP Protocol Traffic
Trace RSVP path messages in detail:
[edit]
protocols {
rsvp {
traceoptions {
file rsvp size 10m files 5;
flag path;
}
}
}
Trace all RSVP messages:
[edit]
protocols {
rsvp {
traceoptions {
384
Copyright © 2011, Juniper Networks, Inc.
Chapter 12: RSVP Configuration Guidelines
file rsvp size 10m files 5;
flag packets;
}
}
}
Trace all RSVP error conditions:
[edit]
protocols {
rsvp {
traceoptions {
file rsvp size 10m files 5;
flag error;
}
}
}
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Copyright © 2011, Juniper Networks, Inc.
CHAPTER 13
Summary of RSVP Configuration
Statements
This chapter provides a reference for each RSVP configuration statement. The statements
are organized alphabetically.
admin-group
Syntax
Hierarchy Level
Release Information
Description
Options
admin-group {
exclude [ group-names ];
include-all [ group-names ];
include-any [ group-names ];
}
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection],
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection bypass bypass-name],
[edit protocols rsvp interface interface-name link-protection],
[edit protocols rsvp interface interface-name link-protection bypass bypass-name]
Statement introduced in Junos OS Release 9.2.
Enable you to configure administrative groups for bypass label-switched paths (LSPs).
You can configure administrative groups either globally for all bypass LSPs traversing an
interface or for just a specific bypass LSP.
exclude group-names—Specify the administrative groups to exclude for a bypass LSP.
include-all group-names—Specify the administrative groups whose links the bypass LSP
must traverse.
include-any group-names—Specify the administrative groups whose links the bypass LSP
can traverse.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Administrative Groups for Bypass LSPs on page 368
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aggregate
Syntax
Hierarchy Level
Release Information
Description
(aggregate | no-aggregate);
[edit logical-systems logical-system-name protocols rsvp interface interface-name],
[edit logical-systems logical-system-name protocols rsvp peer-interface peer-interface-name],
[edit protocols rsvp interface interface-name],
[edit protocols rsvp peer-interface peer-interface-name]
Statement introduced before Junos OS Release 7.4.
Control the use of RSVP aggregate messages on an interface or peer interface:
•
aggregate—Use RSVP aggregate messages.
•
no-aggregate—Do not use RSVP aggregate messages.
Aggregate messages can pack multiple RSVP messages into a single transmission,
thereby reducing network overhead and enhancing efficiency. The number of
supportable sessions and processing overhead are significantly improved when
aggregation is enabled.
Not all routers connected to a subnet need to support aggregation simultaneously.
Each RSVP router negotiates its intention to use aggregate messages on a per-neighbor
basis. Only when both routers agree are aggregate messages sent.
Default
Required Privilege
Level
Related
Documentation
388
Aggregation is disabled.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring RSVP Refresh Reduction on page 357
Copyright © 2011, Juniper Networks, Inc.
Chapter 13: Summary of RSVP Configuration Statements
authentication-key
Syntax
Hierarchy Level
Release Information
Description
authentication-key key;
[edit logical-systems logical-system-name protocols rsvp interface interface-name],
[edit logical-systems logical-system-name protocols rsvp peer-interface peer-interface-name],
[edit protocols rsvp interface interface-name],
[edit protocols rsvp peer-interface peer-interface-name]
Statement introduced before Junos OS Release 7.4.
Authentication key (password). Neighboring routers use the password to verify the
authenticity of packets sent from this interface or peer interface.
RSVP uses HMAC-MD5 authentication, which is defined in RFC 2104, HMAC:
Keyed-Hashing for Message Authentication.
All routers that are connected to the same IP subnet must use the same authentication
scheme and password.
Options
key—Authentication password. It can be 1 through 16 contiguous digits or letters. Separate
decimal digits with periods. Separate hexadecimal digits with periods and precede
the string with 0x. If you include spaces in the password, enclose the entire password
in quotation marks (" ").
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring RSVP Authentication on page 360
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bandwidth
Syntax
Hierarchy Level
Release Information
Description
bandwidth bps;
[edit logical-systems logical-system-name protocols rsvp interface interface-name],
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection],
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection bypass bypass-name],
[edit protocols rsvp interface interface-name],
[edit protocols rsvp interface interface-name link-protection],
[edit protocols rsvp interface interface-name link-protection bypass bypass-name]
Statement introduced before Junos OS Release 7.4.
For certain logical interfaces (such as Asynchronous Transfer Mode [ATM], Permanent
Virtual Circuit [PVC], or Frame Relay), you cannot determine the correct bandwidth from
the hardware. This statement enables you to specify the actual available bandwidth.
This statement also enables you to specify the bandwidth for a bypass label switched
path (LSP). If you have configured multiple bypasses, this statement is mandatory and
is applied to all of the bypass LSPs.
Default
Options
The hardware raw bandwidth is used.
bps—Bandwidth in bits per second. You can specify this as an integer value. If you do so,
count your zeros carefully, or you can use the abbreviations k (for a thousand), m
(for a million), or g (for a billion [also called a thousand million]).
Range: Any positive integer
Default: 0 (no bandwidth is reserved)
Required Privilege
Level
Related
Documentation
390
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Bandwidth for Bypass LSPs on page 369
•
Configuring Link Protection on Interfaces Used by LSPs on page 366
•
Configuring Bypass LSPs on page 367
Copyright © 2011, Juniper Networks, Inc.
Chapter 13: Summary of RSVP Configuration Statements
bypass (Signaled LSP)
Syntax
Hierarchy Level
Release Information
Description
bypass bypass-name {
bandwidth bps;
description text;
hop-limit number;
no-cspf;
path address <strict | loose>;
priority setup-priority reservation-priority;
to address;
}
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection],
[edit protocols rsvp interface interface-name link-protection]
Statement introduced before Junos OS Release 7.4.
The description option was added in Junos OS Release 10.4.
Enables you to configure specific bandwidth and path constraints for a bypass LSP. It is
possible to individually configure multiple bypass LSPs. If you do not configure the bypass
LSPs individually, they all share the same path and bandwidth constraints.
If you specify the bandwidth, hop-limit, and path statements for the bypass LSP, these
values take precedence over the values configured at the [edit protocols rsvp interface
interface-name link-protection] hierarchy level. The other attributes (subscription,
no-node-protection, and optimize-timer) are inherited from the general constraints.
Options
bypass-name—(Required) Specify a name for the bypass LSP. The name can be up to
64 characters.
description—Provides a textual description of the bypass LSP. Enclose any descriptive
text that includes spaces in quotation marks (" "). Any descriptive text you include
is displayed in the output of the show mpls lsp bypass detail command and has no
effect on the operation of the bypass LSP. The description text can be no more than
80 characters in length.
to address—(Required) Specify the address for the interface of the immediate next-hop
node (for link protection) or the next-next-hop node (for node-link protection). The
address specified determines whether this is a link protection bypass or a node-link
protection bypass. On multiaccess networks (for example, a LAN), this address is
also used to specify which next-hop node is being protected.
The remaining statements are explained separately.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Bypass LSPs on page 367
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bypass (Static LSP)
Syntax
Hierarchy Level
Release Information
Description
bypass bypass-name {
bandwidth bps;
description string;
next-hop (address | interface-name | address/interface-name);
push out-label;
to address;
}
[edit logical-systems logical-system-name protocols mpls static-label-switched-path
lsp-name],
[edit protocols mpls static-label-switched-path lsp-name]
Statement introduced before Junos OS Release 10.1.
Configure specific bandwidth and path constraints for a bypass ingress LSP. It is possible
to configure multiple bypass LSPs individually. If you do not, they all share the same path
and bandwidth constraints.
The remaining statements are explained separately.
Required Privilege
Level
Related
Documentation
392
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Static LSPs on page 193
Copyright © 2011, Juniper Networks, Inc.
Chapter 13: Summary of RSVP Configuration Statements
class-of-service
Syntax
Hierarchy Level
Release Information
Description
class-of-service cos-value;
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection],
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection bypass bypass-name],
[edit protocols rsvp interface interface-name link-protection],
[edit protocols rsvp interface interface-name link-protection bypass bypass-name]
Statement introduced before Junos OS Release 7.4.
Class-of-service (CoS) value given to all packets in the bypass LSP. You can specify a
single CoS value for all the bypass LSPs traversing an interface. You can also configure
CoS values for specific bypass LSPs traversing an interface.
The CoS value might affect the scheduling or queuing algorithm of traffic traveling along
an LSP.
Options
cos-value—CoS value. A higher value typically corresponds to a higher level of service.
Range: 0 through 7
Default: If you do not specify a CoS value, the IP precedence bits from the packet’s IP
header are used as the packet’s CoS value.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Class of Service for Bypass LSPs on page 369
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disable
Syntax
Hierarchy Level
Release Information
Description
Default
Required Privilege
Level
Related
Documentation
394
disable;
[edit logical-systems logical-system-name protocols rsvp],
[edit logical-systems logical-system-name protocols rsvp graceful-restart],
[edit logical-systems logical-system-name protocols rsvp interface interface-name],
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection],
[edit logical-systems logical-system-name protocols rsvp peer-interface peer-interface-name],
[edit protocols rsvp],
[edit protocols rsvp graceful-restart],
[edit protocols rsvp interface interface-name],
[edit protocols rsvp interface interface-name link-protection],
[edit protocols rsvp peer-interface peer-interface-name]
Statement introduced before Junos OS Release 7.4.
Explicitly disable RSVP or RSVP graceful restart. Explicitly disable link protection on the
specified interface.
RSVP is enabled on interfaces and peer interfaces configured with the RSVP interface
statement. RSVP graceful restart is enabled on the router. Link protection is disabled.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Minimum RSVP Configuration on page 355
•
Configuring RSVP Graceful Restart on page 374
•
Configuring Link Protection on Interfaces Used by LSPs on page 366
Copyright © 2011, Juniper Networks, Inc.
Chapter 13: Summary of RSVP Configuration Statements
fast-reroute
Syntax
Hierarchy Level
Release Information
Description
Options
fast-reroute optimize-timer seconds;
[edit logical-systems logical-system-name protocols rsvp],
[edit protocols rsvp]
Statement added in Junos OS Release 7.5.
Configure the optimize timer for fast reroute. The optimize timer triggers a periodic
optimization process that recomputes the fast reroute detour LSPs to use network
resources more efficiently.
seconds—Specify the number of seconds between fast reroute detour LSP optimizations.
Range: 0 through 65,535 seconds
Default: 0 (disabled)
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Optimization Interval for Fast Reroute Paths on page 136
graceful-deletion-timeout
Syntax
Hierarchy Level
Release Information
Description
Options
graceful-deletion-timeout seconds;
[edit logical-systems logical-system-name protocols rsvp],
[edit protocols rsvp]
Statement introduced before Junos OS Release 7.4.
Specify the time, in seconds, before completing graceful deletion of signaling.
seconds—Time before completing graceful deletion of signaling.
Range: 1 through 300 seconds
Default: 30 seconds
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Graceful Deletion Timeout Interval on page 561
Copyright © 2011, Juniper Networks, Inc.
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graceful-restart
Syntax
Hierarchy Level
Release Information
Description
Options
graceful-restart {
disable;
helper-disable;
maximum-helper-recovery-time seconds;
maximum-helper-restart-time seconds;
}
[edit logical-systems logical-system-name routing-options],
[edit protocols rsvp],
[edit routing-options]
Statement introduced before Junos OS Release 7.4.
Enable graceful restart on the router. You must configure the graceful-restart statement
at the [edit routing-options] hierarchy level to enable graceful restart on the router.
disable—Disable graceful restart on the router or for RSVP.
helper-disable—Disable RSVP graceful restart helper mode (this option is only available
at the [edit protocols rsvp] hierarchy level).
Default: Helper mode is enabled by default.
maximum-helper-recovery-time seconds—The maximum length of time the router stores
the state of neighboring routers when they undergo a graceful restart. The value
applies to all neighboring routers, so it should be based on the time that the slowest
RSVP neighbor requires for restart.
Default: 180 seconds
Range: 1 through 3600 seconds
maximum-helper-restart-time seconds—The maximum length of time the router waits
between when it discovers that a neighboring router has gone down and when it
declares the neighbor down. This value is applied to all neighboring routers, so it
should be based on the time that the slowest RSVP neighbor requires for restart.
Default: 20 seconds
Range: 1 through 1800 seconds
Required Privilege
Level
Related
Documentation
396
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring RSVP Graceful Restart on page 374
Copyright © 2011, Juniper Networks, Inc.
Chapter 13: Summary of RSVP Configuration Statements
hello-acknowledgements
Syntax
Hierarchy Level
Release Information
Description
Default
Required Privilege
Level
Related
Documentation
hello-acknowledgements;
[edit logical-systems logical-systems-name protocols rsvp],
[edit protocols rsvp]
Statement introduced in Junos OS Release 10.2.
Enable hello messages from nonsession neighbors to be acknowledged with a hello
acknowledgment message. Once hello acknowledgments are enabled, the router
continues to acknowledge hello messages from any nonsession RSVP neighbors unless
the interface itself goes down or the configuration is changed by an administrator.
Hello acknowledgments are disabled.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Hello Acknowledgments for Nonsession RSVP Neighbors on page 363
hello-interval
Syntax
Hierarchy Level
Release Information
Description
Options
hello-interval seconds;
[edit logical-systems logical-system-name protocols rsvp interface interface-name],
[edit logical-systems logical-system-name protocols rsvp peer-interface peer-interface-name],
[edit protocols rsvp interface interface-name],
[edit protocols rsvp peer-interface peer-interface-name]
Statement introduced before Junos OS Release 7.4.
Enable the sending of hello packets on the interface.
seconds—Length of time between hello packets. A value of 0 disables the sending of
hello packets on the interface.
Range: 1 through 60 seconds
Default: 9 seconds
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the RSVP Hello Interval on page 360
Copyright © 2011, Juniper Networks, Inc.
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hop-limit
Syntax
Hierarchy Level
Release Information
Description
Options
hop-limit number;
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection],
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection bypass bypass-name],
[edit protocols rsvp interface interface-name link-protection],
[edit protocols rsvp interface interface-name link-protection bypass bypass-name]
Statement introduced before Junos OS Release 7.4.
Specify the maximum number of hops a bypass can traverse. By default, each bypass
can traverse a maximum of 255 hops, including the ingress and egress routers.
number—Maximum number of hops a bypass can traverse.
Range: 2 through 255 hops
Default: 255 hops
Required Privilege
Level
Related
Documentation
398
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Hop Limit for Bypass LSPs on page 370
Copyright © 2011, Juniper Networks, Inc.
Chapter 13: Summary of RSVP Configuration Statements
interface
Syntax
Hierarchy Level
interface interface-name {
disable;
(aggregate | no-aggregate);
authentication-key key;
bandwidth bps;
hello-interval seconds;
link-protection {
disable;
admin-group {
exclude [ group-names ];
include-all [ group-names ];
include-any [ group-names ];
}
bandwidth bps;
bypass bypass-name {
bandwidth bps {
ct0 bps;
ct1 bps;
ct2 bps;
ct3 bps;
}
description text;
class-of-service cos-value;
hop-limit number;
no-cspf;
path address <strict | loose>;
priority setup-priority reservation-priority;
to address;
}
class-of-service cos-value;
hop-limit number;
max-bypasses number;
no-cspf;
no-node-protection;
optimize-timer seconds;
path address <strict | loose>;
priority setup-priority reservation-priority;
subscription percentage;
}
(reliable | no-reliable);
subscription percentage {
ct0 percentage;
ct1 percentage;
ct2 percentage;
ct3 percentage;
}
update-threshold threshold;
}
[edit logical-systems logical-system-name protocols rsvp],
[edit protocols rsvp]
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Release Information
Description
Default
Options
Statement introduced before Junos OS Release 7.4.
Enable RSVP on one or more router interfaces.
RSVP is disabled on all interfaces.
interface-name—Name of an interface. To configure all interfaces, specify all. For details
about specifying interfaces, see the Junos OS Network Interfaces Configuration Guide.
The remaining statements are explained separately.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Minimum RSVP Configuration on page 355
keep-multiplier
Syntax
Hierarchy Level
Release Information
Description
Options
keep-multiplier number;
[edit logical-systems logical-system-name protocols rsvp],
[edit protocols rsvp]
Statement introduced before Junos OS Release 7.4.
Set the keep multiplier value.
number—Multiplier value.
Range: 1 through 255
Default: 3
Required Privilege
Level
Related
Documentation
400
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Timers for RSVP Refresh Messages on page 378
Copyright © 2011, Juniper Networks, Inc.
Chapter 13: Summary of RSVP Configuration Statements
link-protection (RSVP)
Syntax
Hierarchy Level
Release Information
Description
Default
Options
link-protection {
disable;
admin-group {
exclude [ group-names ];
include-all [ group-names ];
include-any [ group-names ];
}
bandwidth bps;
bypass bypass-name {
bandwidth bps {
ct0 bps;
ct1 bps;
ct2 bps;
ct3 bps;
}
description text;
class-of-service cos-value;
hop-limit number;
no-cspf;
path address <strict | loose>;
priority setup-priority reservation-priority;
to address;
}
class-of-service cos-value;
hop-limit number;
max-bypasses number;
no-cspf;
no-node-protection;
optimize-timer seconds;
path address <strict | loose>;
priority setup-priority reservation-priority;
subscription percentage;
}
[edit logical-systems logical-system-name protocols rsvp interface interface-name],
[edit protocols rsvp interface interface-name]
Statement introduced before Junos OS Release 7.4.
Enable link protection on the specified interface. Using link protection, you can configure
a network to reroute traffic quickly around broken links. To fully enable link protection,
you also need to configure the link-protection statement at the [edit protocols mpls
label-switched-path lsp-name] hierarchy level. You can configure single or multiple
bypasses for protected interface.
Link protection is disabled.
no-node-protection—Disable node-link protection on the RSVP interface. Link protection
remains active. When this option is configured, the router can only initiate a next-hop
bypass, not a next-next-hop bypass.
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The remaining statements are explained separately.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Link Protection on Interfaces Used by LSPs on page 366
•
link-protection (Dynamic LSPs) on page 285
load-balance
Syntax
Hierarchy Level
Release Information
Description
Options
load-balance {
bandwidth;
}
[edit logical-systems logical-system-name protocols rsvp],
[edit protocols rsvp]
Statement introduced before Junos OS Release 7.4.
Load-balance traffic between RSVP LSPs.
bandwidth—Load-balance traffic between RSVP LSPs based on the bandwidth configured
for each LSP.
Required Privilege
Level
Related
Documentation
402
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Load Balancing Across RSVP LSPs on page 376
Copyright © 2011, Juniper Networks, Inc.
Chapter 13: Summary of RSVP Configuration Statements
max-bypasses
Syntax
Hierarchy Level
Release Information
Description
Options
max-bypasses number;
[edit logical-systems logical-system-name protocols rsvp interface interface-name],
[edit protocols rsvp interface interface-name]
Statement introduced before Junos OS Release 7.4.
Range modified in Junos OS Release 9.3.
Specify the maximum number of dynamic bypass LSPs permitted for protecting this
interface. When this option is configured, multiple bypasses for link protection are enabled.
Call admission control (CAC) is also enabled. The limit on bypasses configured applies
only to dynamically generated bypass LSPs. By default, this option is disabled and only
one dynamic bypass LSP is enabled for each interface. If you configure max-bypasses,
you must also configure the bandwidth statement.
number—Configure the maximum number of bypass LSPs. If you configure a value of 0,
no dynamic bypass LSPs are allowed to be established for the interface. Only static
bypass LSPs can be configured.
Range: 0 through 99
Default: 1
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Maximum Number of Bypass LSPs on page 370
Copyright © 2011, Juniper Networks, Inc.
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no-local-reversion
Syntax
Hierarchy Level
Release Information
Description
no-local-reversion;
[edit logical-systems logical-system-name protocols rsvp],
[edit protocols rsvp]
Statement introduced in Junos OS Release 10.4.
Disables RSVP local revertive mode as specified in RFC 4090, Fast Reroute Extensions
to RSVP-TE for LSP Tunnels. RSVP local revertive mode is supported on all Juniper
Networks routers running the Junos OS. It is the default behavior. If you include this
statement, the Juniper Networks router uses global revertive mode instead. You might
need to disable RSVP local revertive mode on Juniper Networks routers if your network
includes equipment that does not support this mode.
The following information can also be found in RFC 4090. Refer to the full RFC for
additional information. When an LSP fails, the connection can be repaired locally using
a traffic protection mechanism such as fast reroute. To restore the LSP to a full working
path, RFC 4090 specifies the following strategies:
Required Privilege
Level
404
•
Local revertive mode—Upon detecting that the path is restored, the point of local repair
(PLR) resignals each of the LSPs that were formerly routed over the restored path.
Every LSP successfully resignaled along the restored path is switched back.
•
Global revertive mode—The ingress router of each tunnel is responsible for reoptimizing
the LSPs that used the failed path. There are several potential reoptimization triggers:
RSVP error messages, inspection of OSPF LSAs or IS-IS LSPs, and timers. This
re-optimization process can proceed as soon as the failure is detected. It is not tied to
the restoration of the failed path.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
Copyright © 2011, Juniper Networks, Inc.
Chapter 13: Summary of RSVP Configuration Statements
node-hello
Syntax
Hierarchy Level
Release Information
Description
Required Privilege
Level
Related
Documentation
node-hello;
[edit logical-systems logical-system-name protocols rsvp],
[edit protocols rsvp]
Statement introduced in JUNOS Release 10.0.
Enables node-ID based RSVP hellos globally on all of the RSVP interfaces on the router
to allow Juniper Networks routers to interoperate with the equipment of other vendors.
By default, the JUNOS Software uses interface-based RSVP hellos and node-ID based
RSVP hellos are disabled. If you have not enabled RSVP node IDs on the router, the
JUNOS software does not accept any node-ID hello packets.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring RSVP Node ID Hellos on page 363
no-adjacency-down-notification
Syntax
Hierarchy Level
Release Information
Description
Required Privilege
Level
Related
Documentation
no-adjacency-down-notification;
[edit logical-systems logical-system-name protocols isis interface interface-name],
[edit protocols isis interface interface-name]
Statement introduced in Junos OS Release 8.0.
Disable adjacency down notification for IS-IS to allow for migration from IS-IS to OSPF
without disruption of the RSVP neighbors and associated RSVP-signaled LSPs.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Disabling Adjacency Down and Neighbor Down Notification in IS-IS and OSPF on
page 382
no-aggregate
See
aggregate.
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Junos OS 11.4 MPLS Applications Configuration Guide
no-cspf
Syntax
Hierarchy Level
Release Information
Description
Default
Required Privilege
Level
Related
Documentation
no-cspf;
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection],
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection bypass bypass-name],
[edit protocols rsvp interface interface-name link-protection],
[edit protocols rsvp interface interface-name link-protection bypass bypass-name]
Statement introduced in Junos OS Release 7.5.
Disable CSPF computation on all bypass LSPs or on a specific bypass LSP. You need to
disable CSPF for link protection to function properly on interarea paths.
CSPF is enabled.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Disabling CSPF for Bypass LSPs on page 371
no-interface-hello
Syntax
Hierarchy Level
Release Information
Description
Required Privilege
Level
Related
Documentation
406
no-interface-hello;
[edit logical-systems logical-system-name protocols rsvp],
[edit protocols rsvp]
Statement introduced in JUNOS Release 10.0.
Allows you to explicitly disable RSVP interface hellos globally on the router. This type of
configuration might be necessary in networks where the Juniper Networks router has
numerous RSVP connections with equipment from other vendors. However, if you disable
RSVP interface hellos globally, you can also configure a hello interval on an RSVP interface
using the hello-interval statement. This configuration disables RSVP interface hellos
globally but enables RSVP interface hellos on the specified interface. This configuration
might be necessary in a heterogeneous network where some devices support RSVP node
ID hellos and other devices support RSVP interface hellos.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring RSVP Node ID Hellos on page 363
•
hello-interval on page 397
Copyright © 2011, Juniper Networks, Inc.
Chapter 13: Summary of RSVP Configuration Statements
no-neighbor-down-notification
Syntax
Hierarchy Level
Release Information
Description
Required Privilege
Level
Related
Documentation
no-neighbor-down-notification;
[edit logical-systems logical-system-name protocols ospf area area-id interface
interface-name],
[edit protocols ospf area area-id interface interface-name]
Statement introduced in Junos OS Release 8.0.
Disable neighbor down notification for OSPF to allow for migration from OSPF to IS-IS
without disruption of the RSVP neighbors and associated RSVP-signaled LSPs.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Disabling Adjacency Down and Neighbor Down Notification in IS-IS and OSPF on
page 382
no-node-id-subobject
Syntax
Hierarchy Level
Release Information
Description
Required Privilege
Level
Related
Documentation
no-node-id-subobject;
[edit logical-systems logical-system-name protocols rsvp],
[edit protocols rsvp]
Statement introduced in Junos OS Release 9.4.
Disable the record route object (RRO) node ID subobject for compatibility with earlier
versions of the Junos OS. To interoperate with other vendors’ equipment, the Junos OS
supports the RRO node ID subobject for use in inter-AS link and node protection
configurations.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Inter-AS Node and Link Protection on page 366
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
no-p2mp-sublsp
Syntax
Hierarchy Level
Release Information
Description
Default
Required Privilege
Level
Related
Documentation
no-p2mp-sublsp;
[edit logical-systems logical-system-name protocols rsvp],
[edit protocols rsvp]
Statement introduced in Junos OS Release 9.2.
Reject Resv messages that include the S2L_SUB_LSP object. By default, Resv messages
that include the S2L_SUB_LSP object are accepted. However, in a network which includes
Juniper Networks devices running both Junos OS Release 9.2 and later and Junos OS
Release 9.1 and earlier, it is necessary to configure the no-p2mp-sublsp statement on
devices running Junos OS Release 9.2 and later to ensure that point-to-multipoint LSPs
function properly.
Resv messages that include the S2L_SUB_LSP object are accepted.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Preserving Point-to-Multipoint LSP Functioning with Different Junos OS Releases on
page 209
no-reliable
See
reliable
node-link-protection
Syntax
Hierarchy Level
Release Information
Description
Default
Required Privilege
Level
Related
Documentation
408
node-link-protection;
[edit logical-systems logical-system-name protocols mpls label-switched-path lsp-name],
[edit protocols mpls label-switched-path lsp-name]
Statement introduced before Junos OS Release 7.4.
Enable node and link protection on the specified LSP. To fully enable node and link
protection, you also need to include the link-protection statement at the [edit protocols
rsvp interface interface-name] hierarchy level.
Node and link protection is disabled.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Node Protection or Link Protection for LSPs on page 364
Copyright © 2011, Juniper Networks, Inc.
Chapter 13: Summary of RSVP Configuration Statements
optimize-timer
Syntax
Hierarchy Level
Release Information
Description
Options
optimize-timer seconds;
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection],
[edit protocols rsvp interface interface-name link-protection]
Statement introduced before Junos OS Release 7.4.
Configure an optimize timer for a bypass LSP. The optimize timer initiates a periodic
optimization process that reshuffles data LSPs among bypass LSPs to achieve the most
efficient use of network resources. The optimization process attempts to either minimize
the number of bypasses currently in use, minimize the total amount of bandwidth reserved
for all bypasses, or both.
seconds—Specify the number of seconds between optimizations.
Range: 0 through 65,535 seconds
Default: 0 (disabled)
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Optimization Interval for Bypass LSPs on page 371
Copyright © 2011, Juniper Networks, Inc.
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path
Syntax
Hierarchy Level
Release Information
path address <strict | loose>;
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection],
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection bypass bypass-name],
[edit protocols rsvp interface interface-name link-protection],
[edit protocols rsvp interface interface-name link-protection bypass bypass-name]
Statement introduced before Junos OS Release 7.4.
Description
Configure an explicit path (a sequence of strict or loose routes) to control where and
how a bypass LSP is established. If multiple bypasses are configured, they all will use
the same explicit path.
Default
No path is configured. CSPF automatically calculates the path the bypass LSP takes.
Options
address—IP address of each transit router in the LSP. You must specify the address or
hostname of each transit router, although you do not need to list each transit router
if its type is loose. As an option, you can include the ingress and egress routers in the
path. Specify the addresses in order, starting with the ingress router (optional) or
the first transit router, and continuing sequentially along the path until reaching the
egress router (optional) or the router immediately before the egress router.
Default: If you do not specify any routers explicitly, no routing limitations are imposed
on the bypass LSP.
loose—(Optional) The next address in the path statement is loose. The LSP can traverse
other routers before reaching this router.
Default: strict
strict—(Optional) The LSP must go to the next address specified in the path statement
without traversing other nodes. This is the default.
Required Privilege
Level
Related
Documentation
410
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring an Explicit Path for Bypass LSPs on page 372
Copyright © 2011, Juniper Networks, Inc.
Chapter 13: Summary of RSVP Configuration Statements
peer-interface
Syntax
Hierarchy Level
Release Information
Description
peer-interface peer-interface-name {
disable;
(aggregate | no-aggregate);
authentication-key key;
hello-interval seconds;
(reliable | no-reliable);
}
[edit logical-systems logical-system-name protocols rsvp],
[edit protocols rsvp]
Statement introduced before Junos OS Release 7.4.
Configure the name of the LMP peer device.
The remaining statements are explained separately.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring RSVP and OSPF for LMP Peer Interfaces on page 555
Copyright © 2011, Juniper Networks, Inc.
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preemption
Syntax
Hierarchy Level
Release Information
Description
Default
Options
preemption {
(aggressive | disabled | normal);
soft-preemption {
cleanup-timer seconds;
}
}
[edit logical-systems logical-system-name protocols rsvp],
[edit protocols rsvp]
Statement introduced before Junos OS Release 7.4.
Control RSVP session preemption.
normal
aggressive—Preempt RSVP sessions whenever bandwidth is insufficient to handle all
sessions. A session is preempted whenever bandwidth is lowered or a new
higher-priority session is established.
disabled—Do not preempt RSVP sessions.
normal—Preempt RSVP sessions to accommodate new higher-priority sessions when
bandwidth is insufficient to handle all sessions.
The remaining statements are explained separately.
Required Privilege
Level
Related
Documentation
412
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Preempting RSVP Sessions on page 379
Copyright © 2011, Juniper Networks, Inc.
Chapter 13: Summary of RSVP Configuration Statements
priority
Syntax
Hierarchy Level
Release Information
priority setup-priority reservation-priority;
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection],
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection bypass bypass-name],
[edit protocols rsvp interface interface-name link-protection],
[edit protocols rsvp interface interface-name link-protection bypass bypass-name],
Statement introduced before Junos OS Release 7.4.
Description
Configure the setup priority and reservation priority for a bypass LSP. If insufficient link
bandwidth is available during session establishment, the setup priority is compared with
other setup priorities for established sessions on the link to determine whether some of
them should be preempted to accommodate the new session. The session with the
lower-hold priority is preempted.
Options
reservation-priority—Reservation priority, used to keep a reservation after it has been set
up. A smaller number has a higher priority. The priority must be greater than or equal
to the setup priority to prevent preemption loops.
Range: 0 through 7, where 0 is the highest and 7 is the lowest priority.
Default: 0 (Once the session is set up, no other session can preempt it.)
setup-priority—Setup priority.
Range: 0 through 7, where 0 is the highest and 7 is the lowest priority.
Default: 7 (The session cannot preempt any existing sessions.)
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Priority and Preemption for Bypass LSPs on page 373
•
Configuring Priority and Preemption for LSPs on page 161
Copyright © 2011, Juniper Networks, Inc.
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refresh-time
Syntax
Hierarchy Level
Release Information
Description
Options
refresh-time seconds;
[edit logical-systems logical-system-name protocols rsvp],
[edit protocols rsvp]
Statement introduced before Junos OS Release 7.4.
Set the refresh time.
seconds—Refresh time.
Range: 1 through 65,535
Default: 30 seconds
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Timers for RSVP Refresh Messages on page 378
reliable
Syntax
Hierarchy Level
Release Information
Description
Required Privilege
Level
Related
Documentation
414
(reliable | no-reliable);
[edit logical-systems logical-system-name protocols rsvp interface interface-name],
[edit logical-systems logical-system-name protocols rsvp peer-interface peer-interface-name],
[edit protocols rsvp interface interface-name],
[edit protocols rsvp peer-interface peer-interface-name]
Statement introduced before Junos OS Release 7.4.
Enable reliable message delivery on the interface.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring RSVP Refresh Reduction on page 357
Copyright © 2011, Juniper Networks, Inc.
Chapter 13: Summary of RSVP Configuration Statements
rsvp
Syntax
Hierarchy Level
Release Information
Description
rsvp { ... }
[edit logical-systems logical-system-name protocols],
[edit protocols]
Statement introduced before Junos OS Release 7.4.
Enable RSVP routing on the router.
You must include the rsvp statement in the configuration to enable RSVP on the router.
Default
Required Privilege
Level
Related
Documentation
RSVP is disabled on the router.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Minimum RSVP Configuration on page 355
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
rsvp-te
Syntax
Hierarchy Level
Release Information
rsvp-te entry-name {
destination-networks network-prefix;
label-switched-path-template {
default-template;
template-name;
}
}
[edit logical-systems logical-system-name routing-options dynamic-tunnels tunnel-name],
[edit routing-options dynamic-tunnels tunnel-name]
Statement introduced in Junos OS Release 10.1.
Description
Enable RSVP to automatically establish LSPs for any new PE router added to a full mesh
of LSPs. To enable this feature, you must configure the rsvp-te statement on all of the
PE routers in the full mesh.
Options
destination-networks network-prefix—Specify the IP version 4 (IPv4) prefix range for the
destination network. Dynamic tunnels within the specified IPv4 prefix range are
allowed to be initiated.
entry-name—Specify the entry for the RSVP tunnel.
label-switched-path-template—Configure the default template using the default-template
option, or configure your own template using the template-name option.
Usage Guidelines
Required Privilege
Level
416
See “Configuring RSVP Automatic Mesh” on page 377.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
Copyright © 2011, Juniper Networks, Inc.
Chapter 13: Summary of RSVP Configuration Statements
setup-protection
Syntax
Hierarchy Level
Description
Required Privilege
Level
Related
Documentation
setup-protection;
[edit logical-systems logical-system-name protocols rsvp],
[edit protocols rsvp]
The facility-backup fast reroute mechanism can provide setup protection for LSPs which
are in the process of being signaled. Both point-to-point LSPs and point-to-multipoint
LSPs are supported. You should configure the setup-protection statement on each of
the routers along the LSP path on which you want to enable LSP setup protection. You
should also configure IGP traffic engineering on all of the routers on the LSP path.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring RSVP Setup Protection on page 374
soft-preemption
Syntax
Hierarchy Level
Release Information
Description
Options
soft-preemption {
cleanup-timer seconds;
}
[edit logical-systems logical-system-name protocols rsvp preemption],
[edit protocols rsvp preemption]
Statement introduced before Junos OS Release 7.4.
Enable soft preemption to attempt to establish a new path for a preempted LSP before
tearing it down.
cleanup-timer—A value of 0 disables soft preemption.
Range: 0 through 180 seconds
Default: 30 seconds
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring MPLS Soft Preemption on page 144
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
subscription
Syntax
Hierarchy Level
Release Information
subscription percentage {
ct0 percentage;
ct1 percentage;
ct2 percentage;
ct3 percentage;
}
[edit logical-systems logical-system-name protocols rsvp interface interface-name],
[edit logical-systems logical-system-name protocols rsvp interface interface-name
link-protection],
[edit protocols rsvp interface interface-name],
[edit protocols rsvp interface interface-name link-protection]
Statement introduced before Junos OS Release 7.4.
Description
Configure the amount of bandwidth subscribed to a class type (when you have enabled
Differentiated Services) or bypass LSP (when you have enabled link protection).
subscription is the percentage of the link bandwidth that can be used for the RSVP
reservation process.
Options
ctnumber percentage—Percentage of the class-type bandwidth allowed for reservations.
If you specify a value greater than 100, you are oversubscribing the class type. You
can specify bandwidth subscriptions for class types 0 through 3. This option is not
available for bypass LSPs.
Range: 0 through 65,000
Default: 100 percent
percentage—Percentage of the class-type or bypass LSP bandwidth allowed for
reservations. If you specify a value greater than 100, you are oversubscribing the
class type or bypass LSP.
Range: 0 through 65,000
Default: 100 percent
Required Privilege
Level
Related
Documentation
418
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Bandwidth Subscription Percentage for LSPs on page 183
•
Configuring the Amount of Bandwidth Subscribed for Bypass LSPs on page 373
Copyright © 2011, Juniper Networks, Inc.
Chapter 13: Summary of RSVP Configuration Statements
traceoptions
Syntax
Hierarchy Level
Release Information
Description
Default
Options
traceoptions {
file filename <files number> <size size> <world-readable | no-world-readable>;
flag flag <flag-modifier> <disable>;
}
[edit logical-systems logical-system-name protocols rsvp],
[edit protocols rsvp]
Statement introduced before Junos OS Release 7.4.
Enable RSVP-level trace options.
The default RSVP-level trace options are those inherited from the routing protocols
traceoptions statement included at the [edit routing-options] hierarchy level.
disable—(Optional) Disable the tracing operation. You can use this option to disable a
single operation when you have defined a broad group of tracing operations, such
as all.
filename—Name of the file to receive the output of the tracing operation. Enclose the
name within quotation marks. All files are placed in the directory /var/log. We
recommend that you place RSVP tracing output in the file rsvp-log.
files number—(Optional) Maximum number of trace files. When a trace file named
trace-file reaches its maximum size, it is renamed trace-file.0, then trace-file.1, and
so on, until the maximum number of trace files is reached. Then the oldest trace file
is overwritten.
Range: 2 through 1000
Default: 2 files
If you specify a maximum number of files, you must also include the size statement to
specify the maximum file size.
flag—Tracing operation to perform. To specify more than one tracing operation, include
multiple flag statements.
•
all—All tracing operations
•
error—All detected error conditions
•
event—RSVP-related events
•
lmp—RSVP-LMP interactions
•
packets—All RSVP packets
•
path—All path messages
•
pathtear—PathTear messages
•
resv—Resv messages
Copyright © 2011, Juniper Networks, Inc.
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•
resvtear—ResvTear messages
•
route—Routing information
•
state—Session state transitions
flag-modifier—(Optional) Modifier for the tracing flag. You can specify one or more of
these modifiers:
•
detail—Provide detailed trace information
•
receive—Packets being received
•
send—Packets being transmitted
no-world-readable—(Optional) Enable only certain users to read the log file.
size size—(Optional) Maximum size of each trace file, in kilobytes (KB), megabytes (MB),
or gigabytes (GB). When a trace file named trace-file reaches this size, it is renamed
trace-file.0. When the trace-file again reaches this size, trace-file.0 is renamed
trace-file.1 and trace-file is renamed trace-file.0. This renaming scheme continues
until the maximum number of trace files is reached. Then the oldest trace file is
overwritten.
Syntax: xk to specify KB, xm to specify MB, or xg to specify GB
Range: 10 KB through the maximum file size supported on your system
Default: 1 MB
If you specify a maximum file size, you must also include the files statement to specify
the maximum number of files.
world-readable—(Optional) Enable any user to read the log file.
Required Privilege
Level
Related
Documentation
420
routing and trace—To view this statement in the configuration.
routing-control and trace-control—To add this statement to the configuration.
•
Tracing RSVP Protocol Traffic on page 383
Copyright © 2011, Juniper Networks, Inc.
Chapter 13: Summary of RSVP Configuration Statements
transit
Syntax
Hierarchy Level
Release Information
Description
transit incoming-label {
bandwidth bps;
description string;
link-protection bypass-name name;
next-hop (address | interface-name | address/interface-name);
node-protection bypass-name name next-next-label label;
pop;
swap out-label;
}
[edit logical-systems logical-system-name protocols mpls static-label-switched-path
lsp-name],
[edit protocols mpls static-label-switched-path lsp-name]
Statement introduced in Junos OS Release 10.1.
Configure a transit static LSP.
The remaining statements are explained separately.
Options
incoming-label—Incoming label value.
Range: 1000000 through 1048575
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Static LSPs on page 193
Copyright © 2011, Juniper Networks, Inc.
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tunnel-services
Syntax
Hierarchy Level
Release Information
Description
Default
Options
tunnel-services {
devices device-names;
}
[edit protocols rsvp]
Statement introduced in Junos OS Release 8.1.
Enable ultimate-hop popping on point-to-multipoint LSPs. The Junos OS selects one of
the available virtual tunnel (VT) interfaces to de-encapsulate the egress traffic. By default,
the selection process is performed automatically.
Ultimate-hop popping is disabled.
devices device-names—Specify which VT interfaces are used to handle the RSVP traffic.
Range: 0 to 8 devices
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Enabling Ultimate-Hop Popping on Point-to-Multipoint LSPs on page 382
update-threshold
Syntax
Hierarchy Level
Release Information
Description
Options
update-threshold threshold;
[edit logical-systems logical-system-name protocols rsvp interface interface-name],
[edit protocols rsvp interface interface-name]
Statement introduced before Junos OS Release 7.4.
Adjust the threshold at which a change in bandwidth triggers an interior gateway protocol
(IGP) update.
threshold—Specify the percentage change in bandwidth to trigger an IGP update.
Range: 1 through 20 percent
Default: 10 percent
Required Privilege
Level
Related
Documentation
422
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the RSVP Update Threshold on an Interface on page 361
Copyright © 2011, Juniper Networks, Inc.
PART 4
LDP
•
LDP Overview on page 425
•
LDP Configuration Guidelines on page 433
•
Summary of LDP Configuration Statements on page 465
Copyright © 2011, Juniper Networks, Inc.
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424
Copyright © 2011, Juniper Networks, Inc.
CHAPTER 14
LDP Overview
This chapter discusses the following topics:
•
LDP Introduction on page 425
•
Supported LDP Standards on page 426
•
Junos OS LDP Protocol Implementation on page 426
•
LDP Operation on page 427
•
Tunneling LDP LSPs in RSVP LSPs on page 427
•
Tunneling LDP LSPs in RSVP LSPs Overview on page 427
•
Label Operations on page 428
•
LDP Message Types on page 429
•
Discovery Messages on page 429
•
Session Messages on page 430
•
Advertisement Messages on page 430
•
Notification Messages on page 430
•
LDP Session Protection on page 430
•
LDP Graceful Restart on page 431
LDP Introduction
The Label Distribution Protocol (LDP) is a protocol for distributing labels in
non-traffic-engineered applications. LDP allows routers to establish label-switched
paths (LSPs) through a network by mapping network-layer routing information directly
to data link layer-switched paths.
These LSPs might have an endpoint at a directly attached neighbor (comparable to IP
hop-by-hop forwarding), or at a network egress node, enabling switching through all
intermediary nodes. LSPs established by LDP can also traverse traffic-engineered LSPs
created by RSVP.
LDP associates a forwarding equivalence class (FEC) with each LSP it creates. The FEC
associated with an LSP specifies which packets are mapped to that LSP. LSPs are
extended through a network as each router chooses the label advertised by the next hop
Copyright © 2011, Juniper Networks, Inc.
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for the FEC and splices it to the label it advertises to all other routers. This process forms
a tree of LSPs that converge on the egress router.
Supported LDP Standards
The Junos OS substantially supports the following RFCs, which define standards for LDP.
•
RFC 3212, Constraint-Based LSP Setup using LDP
•
RFC 3478, Graceful Restart Mechanism for Label Distribution Protocol
The following RFCs do not define standards, but provide information about LDP. The
IETF classifies them as “Informational.”
•
RFC 3215, LDP State Machine
•
RFC 5036, LDP Specification
For the following features described in the indicated sections of the RFC, the Junos OS
supports one of the possible modes but not the other:
Related
Documentation
•
Label distribution control (section 2.6.1): Ordered mode is supported, but not
Independent mode.
•
Label retention (section 2.6.2): Liberal mode is supported, but not Conservative
mode.
•
Label advertisement (section 2.6.3): Downstream Unsolicited mode is supported,
but not Downstream on Demand mode.
•
RFC 5443, LDP IGP Synchronization
•
Supported GMPLS Standards on page 541
•
Supported MPLS Standards on page 24
•
Supported RSVP Standards on page 338
•
Accessing Standards Documents on the Internet
Junos OS LDP Protocol Implementation
The Junos OS implementation of LDP supports LDP version 1. The Junos OS supports a
simple mechanism for tunneling between routers in an interior gateway protocol (IGP),
to eliminate the required distribution of external routes within the core. The Junos OS
allows an MPLS tunnel next hop to all egress routers in the network, with only an IGP
running in the core to distribute routes to egress routers. Edge routers run BGP but do not
distribute external routes to the core. Instead, the recursive route lookup at the edge
resolves to an LSP switched to the egress router. No external routes are necessary on
the transit LDP routers.
426
Copyright © 2011, Juniper Networks, Inc.
Chapter 14: LDP Overview
LDP Operation
You must configure LDP for each interface on which you want LDP to run. LDP creates
LSP trees rooted at each egress router for the router ID address that is the subsequent
BGP next hop. The ingress point is at every router running LDP. This process provides an
inet.3 route to every egress router. If BGP is running, it will attempt to resolve next hops
by using the inet.3 table first, which binds most, if not all, of the BGP routes to MPLS
tunnel next hops.
Two adjacent routers running LDP become neighbors. If the two routers are connected
by more than one interface, they become neighbors on each interface. When LDP routers
become neighbors, they establish an LDP session to exchange label information. If
per-router labels are in use on both routers, only one LDP session is established between
them, even if they are neighbors on multiple interfaces. For this reason, an LDP session
is not related to a particular interface.
LDP operates in conjunction with a unicast routing protocol. LDP installs LSPs only when
both LDP and the routing protocol are enabled. For this reason, you must enable both
LDP and the routing protocol on the same set of interfaces. If this is not done, LSPs might
not be established between each egress router and all ingress routers, which might result
in loss of BGP-routed traffic.
You can apply policy filters to labels received from and distributed to other routers through
LDP. Policy filters provide you with a mechanism to control the establishment of LSPs.
For LDP to run on an interface, MPLS must be enabled on a logical interface on that
interface. For more information, see the Junos OS Network Interfaces Configuration Guide.
Tunneling LDP LSPs in RSVP LSPs
You can tunnel LDP LSPs over RSVP LSPs. The following sections describe how tunneling
of LDP LSPs in RSVP LSPs works:
•
Tunneling LDP LSPs in RSVP LSPs Overview on page 427
•
Label Operations on page 428
Tunneling LDP LSPs in RSVP LSPs Overview
If you are using RSVP for traffic engineering, you can run LDP simultaneously to eliminate
the distribution of external routes in the core. The LSPs established by LDP are tunneled
through the LSPs established by RSVP. LDP effectively treats the traffic-engineered LSPs
as single hops.
When you configure the router to run LDP across RSVP-established LSPs, LDP
automatically establishes sessions with the router at the other end of the LSP. LDP
control packets are routed hop-by-hop, rather than carried through the LSP. This routing
allows you to use simplex (one-way) traffic-engineered LSPs. Traffic in the opposite
direction flows through LDP-established LSPs that follow unicast routing rather than
through traffic-engineered tunnels.
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If you configure LDP over RSVP LSPs, you can still configure multiple OSPF areas and
IS-IS levels in the traffic engineered core and in the surrounding LDP cloud.
Label Operations
Figure 24 on page 428 depicts an LDP LSP being tunneled through an RSVP LSP. (For
definitions of label operations, see “Label Description” on page 27.) The shaded inner
oval represents the RSVP domain, whereas the outer oval depicts the LDP domain. RSVP
establishes an LSP through routers B, C, D, and E, with the sequence of labels L3, L4. LDP
establishes an LSP through Routers A, B, E, F, and G, with the sequence of labels L1, L2,
L5. LDP views the RSVP LSP between Routers B and E as a single hop.
When the packet arrives at Router A, it enters the LSP established by LDP, and a label
(L1) is pushed onto the packet. When the packet arrives at Router B, the label (L1) is
swapped with another label (L2). Because the packet is entering the traffic-engineered
LSP established by RSVP, a second label (L3) is pushed onto the packet.
This outer label (L3) is swapped with a new label (L4) at the intermediate router (C)
within the RSVP LSP tunnel, and when the penultimate router (D) is reached, the top
label is popped. Router E swaps the label (L2) with a new label (L5), and the penultimate
router for the LDP-established LSP (F) pops the last label.
Figure 24: Swap and Push When LDP LSPs Are Tunneled Through RSVP LSPs
Figure 25 on page 429 depicts a double push label operation (L1L2). A double push label
operation is used when the ingress router (A) for both the LDP LSP and the RSVP LSP
tunneled through it is the same device. Note that Router D is the penultimate hop for the
LDP-established LSP, so L2 is popped from the packet by Router D.
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Figure 25: Double Push When LDP LSPs Are Tunneled Through RSVP LSPs
LDP Message Types
LDP uses the message types described in the following sections to establish and remove
mappings and to report errors. All LDP messages have a common structure that uses a
type, length, and value (TLV) encoding scheme.
•
Discovery Messages on page 429
•
Session Messages on page 430
•
Advertisement Messages on page 430
•
Notification Messages on page 430
Discovery Messages
Discovery messages announce and maintain the presence of a router in a network. Routers
indicate their presence in a network by sending hello messages periodically. Hello
messages are transmitted as UDP packets to the LDP port at the group multicast address
for all routers on the subnet.
LDP uses the following discovery procedures:
•
Basic discovery—A router periodically sends LDP link hello messages through an
interface. LDP link hello messages are sent as UDP packets addressed to the LDP
discovery port. Receipt of an LDP link hello message on an interface identifies an
adjacency with the LDP peer router.
•
Extended discovery—LDP sessions between routers not directly connected are
supported by LDP extended discovery. A router periodically sends LDP targeted hello
messages to a specific address. Targeted hello messages are sent as UDP packets
addressed to the LDP discovery port at the specific address. The targeted router decides
whether to respond to or ignore the targeted hello message. A targeted router that
chooses to respond does so by periodically sending targeted hello messages to the
initiating router.
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Session Messages
Session messages establish, maintain, and terminate sessions between LDP peers. When
a router establishes a session with another router learned through the hello message, it
uses the LDP initialization procedure over TCP transport. When the initialization procedure
is completed successfully, the two routers are LDP peers and can exchange advertisement
messages.
Advertisement Messages
Advertisement messages create, change, and delete label mappings for forwarding
equivalence classes (FECs). Requesting a label or advertising a label mapping to a peer
is a decision made by the local router. In general, the router requests a label mapping
from a neighboring router when it needs one and advertises a label mapping to a
neighboring router when it wants the neighbor to use a label.
Notification Messages
Notification messages provide advisory information and signal error information. LDP
sends notification messages to report errors and other events of interest. There are two
kinds of LDP notification messages:
•
Error notifications, which signal fatal errors. If a router receives an error notification
from a peer for an LDP session, it terminates the LDP session by closing the TCP
transport connection for the session and discarding all label mappings learned through
the session.
•
Advisory notifications, which pass information to a router about the LDP session or the
status of some previous message received from the peer.
LDP Session Protection
LDP session protection is based on the LDP targeted hello functionality defined in RFC
5036, LDP Specification, and is supported by the Junos OS as well as the LDP
implementations of most other vendors. It involves sending unicast User Datagram
Protocol (UDP) hello packets to a remote neighbor address and receiving similar packets
from the neighbor router.
If you configure LDP session protection on a router, the LDP sessions are maintained as
follows:
1.
An LDP session is established between a router and a remote neighboring router.
2. If all of the direct links between the routers go down, the LDP session remains up so
long as there is IP connectivity between the routers based on another connection over
the network.
3. When the direct link between the routers is reestablished, the LDP session is not
restarted. The routers simply exchange LDP hellos with each other over the direct link.
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They can then begin forwarding LDP-signaled MPLS packets using the original LDP
session.
By default, LDP targeted hellos are set to the remote neighbor so long as the LDP session
is up, even if there are no more link neighbors to that router. You can also specify the
duration you would like to maintain the remote neighbor connection in the absence of
link neighbors. When the last link neighbor for a session goes down, the Junos OS starts
an LDP session protection timer. If this timer expires before any of the link neighbors
come back up, the remote neighbor connection is taken down and the LDP session is
terminated. If you configure a different value for the timer while it is currently running,
the Junos OS updates the timer to the specified value without disrupting the current state
of the LDP session.
LDP Graceful Restart
LDP graceful restart enables a router whose LDP control plane is undergoing a restart to
continue to forward traffic while recovering its state from neighboring routers. It also
enables a router on which helper mode is enabled to assist a neighboring router that is
attempting to restart LDP.
During session initialization, a router advertises its ability to perform LDP graceful restart
or to take advantage of a neighbor performing LDP graceful restart by sending the graceful
restart TLV. This TLV contains two fields relevant to LDP graceful restart: the reconnect
time and the recovery time. The values of the reconnect and recovery times indicate the
graceful restart capabilities supported by the router.
When a router discovers that a neighboring router is restarting, it waits until the end of
the recovery time before attempting to reconnect. The recovery time is the length of time
a router waits for LDP to restart gracefully. The recovery time period begins when an
initialization message is sent or received. This time period is also typically the length of
time that a neighboring router maintains its information about the restarting router,
allowing it to continue to forward traffic.
You can configure LDP graceful restart in both the master instance for the LDP protocol
and for a specific routing instance. You can disable graceful restart at the global level
for all protocols, at the protocol level for LDP only, and on a specific routing instance.
LDP graceful restart is disabled by default, because at the global level, graceful restart
is disabled by default. However, helper mode (the ability to assist a neighboring router
attempting a graceful restart) is enabled by default.
The following are some of the behaviors associated with LDP graceful restart:
•
Outgoing labels are not maintained in restarts. New outgoing labels are allocated.
•
When a router is restarting, no label-map messages are sent to neighbors that support
graceful restart until the restarting router has stabilized (label-map messages are
immediately sent to neighbors that do not support graceful restart). However, all other
messages (keepalive, address-message, notification, and release) are sent as usual.
Distributing these other messages prevents the router from distributing incomplete
information.
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•
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Helper mode and graceful restart are independent. You can disable graceful restart in
the configuration, but still allow the router to cooperate with a neighbor attempting
to restart gracefully.
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LDP Configuration Guidelines
This chapter describes the minimum required LDP configuration and discusses the
following configuration tasks:
•
Minimum LDP Configuration on page 434
•
Enabling and Disabling LDP on page 434
•
Configuring the LDP Timer for Hello Messages on page 434
•
Configuring the Delay Before LDP Neighbors Are Considered Down on page 435
•
Enabling Strict Targeted Hello Messages for LDP on page 437
•
Configuring the Interval for LDP Keepalive Messages on page 437
•
Configuring the LDP Keepalive Timeout on page 437
•
Configuring LDP Route Preferences on page 438
•
Configuring LDP Graceful Restart on page 438
•
Filtering Inbound LDP Label Bindings on page 440
•
Filtering Outbound LDP Label Bindings on page 442
•
Specifying the Transport Address Used by LDP on page 444
•
Configuring the Prefixes Advertised into LDP from the Routing Table on page 445
•
Configuring FEC Deaggregation on page 446
•
Configuring Policers for LDP FECs on page 446
•
Configuring LDP IPv4 FEC Filtering on page 447
•
Configuring BFD for LDP LSPs on page 448
•
Configuring ECMP-Aware BFD for LDP LSPs on page 450
•
Configuring a Failure Action for the BFD Session on an LDP LSP on page 450
•
Configuring the Holddown Interval for the BFD Session on page 451
•
Configuring OAM Ingress Policies for LDP on page 451
•
Configuring LDP LSP Traceroute on page 451
•
Collecting LDP Statistics on page 452
•
Tracing LDP Protocol Traffic on page 455
•
Configuring Miscellaneous LDP Properties on page 457
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Minimum LDP Configuration
To enable LDP on a single interface, include the ldp statement and specify the interface
using the interface statement. This is the minimum LDP configuration. All other LDP
configuration statements are optional.
ldp {
interface interface-name;
}
To enable LDP on all interfaces, specify all for interface-name.
For a list of hierarchy levels at which you can include these statements, see the statement
summary sections.
Enabling and Disabling LDP
LDP is routing-instance-aware. To enable LDP on a specific interface, include the following
statements:
ldp {
interface interface-name;
}
For a list of hierarchy levels at which you can include these statements, see the statement
summary sections.
To enable LDP on all interfaces, specify all for interface-name.
If you have configured interface properties on a group of interfaces and want to disable
LDP on one of the interfaces, include the interface statement with the disable option:
interface interface-name {
disable;
}
For a list of hierarchy levels at which you can include this statement, see the statement
summary section.
Configuring the LDP Timer for Hello Messages
LDP hello messages enable LDP nodes to discover one another and to detect the failure
of a neighbor or the link to the neighbor. Hello messages are sent periodically on all
interfaces where LDP is enabled.
There are two types of LDP hello messages:
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•
Link hello messages—Sent through the LDP interface as UDP packets addressed to
the LDP discovery port. Receipt of an LDP link hello message on an interface identifies
an adjacency with the LDP peer router.
•
Targeted hello messages—Sent as UDP packets addressed to the LDP discovery port
at a specific address. Targeted hello messages are used to support LDP sessions
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between routers that are not directly connected. A targeted router determines whether
to respond or ignore a targeted hello message. A targeted router that chooses to
respond does so by periodically sending targeted hello messages back to the initiating
router.
By default, LDP sends hello messages every 5 seconds for link hello messages and every
15 seconds for targeted hello messages. You can configure the LDP timer to alter how
often both types of hello messages are sent. However, you cannot configure a time for
the LDP timer that is greater than the LDP hold time. For more information, see
“Configuring the Delay Before LDP Neighbors Are Considered Down” on page 435.
Configuring the LDP Timer for Link Hello Messages
To modify how often LDP sends link hello messages, specify a new link hello message
interval for the LDP timer using the hello-interval statement:
hello-interval seconds;
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
Configuring the LDP Timer for Targeted Hello Messages
To modify how often LDP sends targeted hello messages, specify a new targeted hello
message interval for the LDP timer by configuring the hello-interval statement as an
option for the targeted-hello statement:
targeted-hello {
hello-interval seconds;
}
For a list of hierarchy levels at which you can include these statements, see the statement
summary sections for these statements.
Configuring the Delay Before LDP Neighbors Are Considered Down
The hold time determines how long an LDP node should wait for a hello message before
declaring a neighbor to be down. This value is sent as part of a hello message so that
each LDP node tells its neighbors how long to wait. The values sent by each neighbor do
not have to match.
The hold time should normally be at least three times the hello interval. The default is
15 seconds for link hello messages and 45 seconds for targeted hello messages. However,
it is possible to configure an LDP hold time that is close to the value for the hello interval.
NOTE: By configuring an LDP hold time close to the hello interval (less than
three times the hello interval), LDP neighbor failures might be detected more
quickly. However, this also increases the possibility that the router might
declare an LDP neighbor down that is still functioning normally. For more
information, see “Configuring the LDP Timer for Hello Messages” on page 434.
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The LDP hold time is also negotiated automatically between LDP peers. When two LDP
peers advertise different LDP hold times to one another, the smaller value is used. If an
LDP peer router advertises a shorter hold time than the value you have configured, the
peer router’s advertised hold time is used. This negotiation can affect the LDP keepalive
interval as well.
If the local LDP hold time is not shortened during LDP peer negotiation, the user-configured
keepalive interval is left unchanged. However, if the local hold time is reduced during
peer negotiation, the keepalive interval is recalculated. If the LDP hold time has been
reduced during peer negotiation, the keepalive interval is reduced to one-third of the new
hold time value. For example, if the new hold-time value is 45 seconds, the keepalive
interval is set to 15 seconds.
This automated keepalive interval calculation can cause different keepalive intervals to
be configured on each peer router. This enables the routers to be flexible in how often
they send keepalive messages, because the LDP peer negotiation ensures they are sent
more frequently than the LDP hold time.
When you reconfigure the hold-time interval, changes do not take effect until after the
session is reset. The hold time is negotiated when the LDP peering session is initiated
and cannot be renegotiated as long as the session is up (required by RFC 5036, LDP
Specification). To manually force the LDP session to reset, issue the clear ldp session
command.
Configuring the LDP Hold Time for Link Hello Messages
To modify how long an LDP node should wait for a link hello message before declaring
the neighbor down, specify a new time in seconds using the hold-time statement:
hold-time seconds;
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
Configuring the LDP Hold Time for Targeted Hello Messages
To modify how long an LDP node should wait for a targeted hello message before
declaring the neighbor down, specify a new time in seconds using the hold-time statement
as an option for the targeted-hello statement:
targeted-hello {
hold-time seconds;
}
For a list of hierarchy levels at which you can include these statements, see the statement
summary sections for these statements.
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Enabling Strict Targeted Hello Messages for LDP
Use strict targeted hello messages to prevent LDP sessions from being established with
remote neighbors that have not been specifically configured. If you configure the
strict-targeted-hellos statement, an LDP peer does not respond to targeted hello
messages coming from a source that is not one of its configured remote neighbors.
Configured remote neighbors can include:
•
Endpoints of RSVP tunnels for which LDP tunneling is configured
•
Layer 2 circuit neighbors
If an unconfigured neighbor sends a hello message, the LDP peer ignores the message
and logs an error (with the error trace flag) indicating the source. For example, if the LDP
peer received a targeted hello from the Internet address 10.0.0.1 and no neighbor with
this address is specifically configured, the following message is printed to the LDP log
file:
LDP: Ignoring targeted hello from 10.0.0.1
To enable strict targeted hello messages, include the strict-targeted-hellos statement:
strict-targeted-hellos;
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
Configuring the Interval for LDP Keepalive Messages
The keepalive interval determines how often a message is sent over the session to ensure
that the keepalive timeout is not exceeded. If no other LDP traffic is sent over the session
in this much time, a keepalive message is sent. The default is 10 seconds. The minimum
value is 1 second.
The value configured for the keepalive interval can be altered during LDP session
negotiation if the value configured for the LDP hold time on the peer router is lower than
the value configured locally. For more information, see “Configuring the Delay Before
LDP Neighbors Are Considered Down” on page 435.
To modify the keepalive interval, include the keepalive-interval statement:
keepalive-interval seconds;
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
Configuring the LDP Keepalive Timeout
After an LDP session is established, messages must be exchanged periodically to ensure
that the session is still working. The keepalive timeout defines the amount of time that
the neighbor LDP node waits before deciding that the session has failed. This value is
usually set to at least three times the keepalive interval. The default is 30 seconds.
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To modify the keepalive interval, include the keepalive-timeout statement:
keepalive-timeout seconds;
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
The value configured for the keepalive-timeout statement is displayed as the hold time
when you issue the show ldp session detail command.
Configuring LDP Route Preferences
When several protocols calculate routes to the same destination, route preferences are
used to select which route is installed in the forwarding table. The route with the lowest
preference value is selected. The preference value can be a number in the range 0 through
255. By default, LDP routes have a preference value of 9.
To modify the route preferences, include the preference statement:
preference preference;
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
Configuring LDP Graceful Restart
When you alter the graceful restart configuration at either the [edit routing-options
graceful-restart] or [edit protocols ldp graceful-restart] hierarchy levels, any running LDP
session is automatically restarted to apply the graceful restart configuration. This behavior
mirrors the behavior of BGP when you alter its graceful restart configuration.
By default, graceful restart helper mode is enabled, but graceful restart is disabled. Thus,
the default behavior of a router is to assist neighboring routers attempting a graceful
restart, but not to attempt a graceful restart itself.
To configure LDP graceful restart, see the following sections:
•
Enabling Graceful Restart on page 438
•
Disabling LDP Graceful Restart or Helper Mode on page 439
•
Configuring Reconnect Time on page 439
•
Configuring Recovery Time and Maximum Recovery Time on page 440
Enabling Graceful Restart
To enable LDP graceful restart, you also need to enable graceful restart on the router.
To enable graceful restart, include the graceful-restart statement:
graceful-restart;
You can include this statement at the following hierarchy levels:
•
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•
[edit logical-systems logical-system-name routing-options]
The graceful-restart statement enables graceful restart for all protocols supporting this
feature on the router. For more information about graceful restart, see the Junos OS
Routing Protocols Configuration Guide.
By default, LDP graceful restart is enabled when you enable graceful restart at both the
LDP protocol level and on all the routing instances. However, you can disable both LDP
graceful restart and LDP graceful restart helper mode.
Disabling LDP Graceful Restart or Helper Mode
To disable LDP graceful restart and recovery, include the disable statement:
ldp {
graceful-restart {
disable;
}
}
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
You can disable helper mode at the LDP protocols level only. You cannot disable helper
mode for a specific routing instance. To disable LDP helper mode, include the
helper-disable statement:
ldp {
graceful-restart {
helper-disable;
}
}
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
The following LDP graceful restart configurations are possible:
•
LDP graceful restart and helper mode are both enabled.
•
LDP graceful restart is disabled but helper mode is enabled. A router configured in this
way cannot restart gracefully but can help a restarting neighbor.
•
LDP graceful restart and helper mode are both disabled. The router does not use LDP
graceful restart or the graceful restart type, length, and value (TLV) sent in the
initialization message. The router behaves as a router that cannot support LDP graceful
restart.
A configuration error is issued if you attempt to enable graceful restart and disable helper
mode.
Configuring Reconnect Time
After the LDP connection between neighbors fails, neighbors wait a certain amount of
time for the gracefully restarting router to resume sending LDP messages. After the wait
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period, the LDP session can be reestablished. You can configure the wait period in seconds.
This value is included in the fault tolerant session TLV sent in LDP initialization messages
when LDP graceful restart is enabled.
Suppose that Router A and Router B are LDP neighbors. Router A is the restarting Router.
The reconnect time is the time that Router A tells Router B to wait after Router B detects
that Router A restarted.
To configure the reconnect time, include the reconnect-time statement:
graceful-restart {
reconnect-time seconds;
}
You can set the reconnect time to a value in the range from 30 through 300 seconds. By
default, it is 60 seconds.
For a list of hierarchy levels at which you can configure these statements, see the
statement summary sections for these statements.
Configuring Recovery Time and Maximum Recovery Time
The recovery time is the amount of time a router waits for LDP to restart gracefully. The
recovery time period begins when an initialization message is sent or received. This period
is also typically the amount of time that a neighboring router maintains its information
about the restarting router, allowing it to continue to forward traffic.
To prevent a neighboring router from being adversely affected if it receives a false value
for the recovery time from the restarting router, you can configure the maximum recovery
time on the neighboring router. A neighboring router maintains its state for the shorter
of the two times. For example, Router A is performing an LDP graceful restart. It has sent
a recovery time of 900 seconds to neighboring Router B. However, Router B has its
maximum recovery time configured at 400 seconds. Router B will only wait for
400 seconds before it purges its LDP information from Router A.
To configure recovery time, include the recovery-time statement and the
maximum-neighbor-recovery-time statement:
graceful-restart {
maximum-neighbor-recovery-time seconds;
recovery-time seconds;
}
For a list of hierarchy levels at which you can configure these statements, see the
statement summary sections for these statements.
Filtering Inbound LDP Label Bindings
You can filter received LDP label bindings, applying policies to accept or deny bindings
advertised by neighboring routers. To configure received-label filtering, include the import
statement:
import [ policy-names ];
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For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
The named policy (configured at the [edit policy-options] hierarchy level) is applied to
all label bindings received from all LDP neighbors. All filtering is done with from
statements. Table 9 on page 441 lists the only from operators that apply to LDP
received-label filtering.
Table 9: from Operators That Apply to LDP Received-Label Filtering
from Operator
Description
interface
Matches on bindings received from a neighbor that is
adjacent over the specified interface
neighbor
Matches on bindings received from the specified LDP
router ID
next-hop
Matches on bindings received from a neighbor advertising
the specified interface address
route-filter
Matches on bindings with the specified prefix
If a binding is filtered, it still appears in the LDP database, but is not considered for
installation as part of a label-switched path (LSP).
Generally, applying policies in LDP can be used only to block the establishment of LSPs,
not to control their routing. This is because the path that an LSP follows is determined
by unicast routing, and not by LDP. However, when there are multiple equal-cost paths
to the destination through different neighbors, you can use LDP filtering to exclude some
of the possible next hops from consideration. (Otherwise, LDP chooses one of the possible
next hops at random.)
LDP sessions are not bound to interfaces or interface addresses. LDP advertises only
per-router (not per-interface) labels; so if multiple parallel links exist between two routers,
only one LDP session is established, and it is not bound to a single interface. When a
router has multiple adjacencies to the same neighbor, take care to ensure that the filter
does what is expected. (Generally, using next-hop and interface is not appropriate in this
case.)
If a label has been filtered (meaning that it has been rejected by the policy and is not
used to construct an LSP), it is marked as filtered in the database:
user@host> show ldp database
Input label database, 10.10.255.1:0-10.10.255.6:0
Label Prefix
3 10.10.255.6/32 (Filtered)
Output label database, 10.10.255.1:0-10.10.255.6:0
Label Prefix
3 10.10.255.1/32 (Filtered)
For more information about how to configure policies for LDP, see the Junos OS Routing
Policy Configuration Guide.
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Examples: Filtering Inbound LDP Label Bindings
Accept only /32 prefixes from all neighbors:
[edit]
protocols {
ldp {
import only-32;
...
}
}
policy-options {
policy-statement only-32 {
term first {
from {
route-filter 0.0.0.0/0 upto /31;
}
then reject;
}
then accept;
}
}
Accept 131.108/16 or longer from router ID 10.10.255.2 and accept all prefixes from all
other neighbors:
[edit]
protocols {
ldp {
import nosy-neighbor;
...
}
}
policy-options {
policy-statement nosy-neighbor {
term first {
from {
neighbor 10.10.255.2;
route-filter 131.108.0.0/16 orlonger accept;
route-filter 0.0.0.0/0 orlonger reject;
}
}
then accept;
}
}
Filtering Outbound LDP Label Bindings
You can configure export policies to filter LDP outbound labels. You can filter outbound
label bindings by applying routing policies to block bindings from being advertised to
neighboring routers. To configure outbound label filtering, include the export statement:
export [policy-name];
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For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
The named export policy (configured at the [edit policy-options] hierarchy level) is applied
to all label bindings transmitted to all LDP neighbors. The only from operator that applies
to LDP outbound label filtering is route-filter, which matches bindings with the specified
prefix. The only to operators that apply to outbound label filtering are the operators in
Table 10 on page 443.
Table 10: to Operators for LDP Outbound-Label Filtering
to Operator
Description
interface
Matches on bindings sent to a neighbor that is adjacent over the specified
interface
neighbor
Matches on bindings sent to the specified LDP router ID
next-hop
Matches on bindings sent to a neighbor advertising the specified interface
address
If a binding is filtered, the binding is not advertised to the neighboring router, but it can
be installed as part of an LSP on the local router. You can apply policies in LDP to block
the establishment of LSPs, but not to control their routing. The path an LSP follows is
determined by unicast routing, not by LDP.
LDP sessions are not bound to interfaces or interface addresses. LDP advertises only
per-router (not per-interface) labels. If multiple parallel links exist between two routers,
only one LDP session is established, and it is not bound to a single interface.
Do not use the next-hop and interface operators when a router has multiple adjacencies
to the same neighbor.
Filtered labels are marked in the database:
user@host> show ldp database
Input label database, 10.10.255.1:0-10.10.255.3:0
Label Prefix
100007 10.10.255.2/32
3 10.10.255.3/32
Output label database, 10.10.255.1:0-10.10.255.3:0
Label Prefix
3 10.10.255.1/32
100001 10.10.255.6/32 (Filtered)
For more information about how to configure policies for LDP, see the Junos OS Routing
Policy Configuration Guide.
Examples: Filtering Outbound LDP Label Bindings
Block transmission of the route for 10.10.255.6/32 to any neighbors:
[edit protocols]
ldp {
export block-one;
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}
policy-options {
policy-statement block-one {
term first {
from {
route-filter 10.10.255.6/32 exact;
}
then reject;
}
then accept;
}
}
Send only 131.108/16 or longer to router ID 10.10.255.2, and send all prefixes to all other
routers:
[edit protocols]
ldp {
export limit-lsps;
}
policy-options {
policy-statement limit-lsps {
term allow-one {
from {
route-filter 131.108.0.0/16 orlonger;
}
to {
neighbor 10.10.255.2;
}
then accept;
}
term block-the-rest {
to {
neighbor 10.10.255.2;
}
then reject;
}
then accept;
}
}
Specifying the Transport Address Used by LDP
You can control the transport address used by LDP. The transport address is the address
used for the TCP session over which LDP is running. To configure transport address
control, include the transport-address statement:
transport-address (router-id | interface);
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
If you specify the router-id option, the address of the router identifier is used as the
transport address (unless otherwise configured, the router identifier is typically the same
as the loopback address). If you specify the interface option, the interface address is used
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as the transport address for any LDP sessions to neighbors that can be reached over that
interface. Note that the router identifier is used as the transport address by default.
You cannot specify the interface option when there are multiple parallel links to the same
LDP neighbor, because the LDP specification requires that the same transport address
be advertised on all interfaces to the same neighbor. If LDP detects multiple parallel links
to the same neighbor, it disables interfaces to that neighbor one by one until the condition
is cleared, either by disconnecting the neighbor on an interface or by specifying the
router-id option.
Configuring the Prefixes Advertised into LDP from the Routing Table
You can control the set of prefixes that are advertised into LDP and cause the router to
be the egress router for those prefixes. By default, only the loopback address is advertised
into LDP. To configure the set of prefixes from the routing table to be advertised into
LDP, include the egress-policy statement:
egress-policy policy-name;
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
NOTE: If you configure an egress policy for LDP that does not include the
loopback address, it is no longer advertised in LDP. To continue to advertise
the loopback address, you need to explicitly configure it as a part of the LDP
egress policy.
The named policy (configured at the [edit policy-options] or [edit logical-systems
logical-system-name policy-options] hierarchy level) is applied to all routes in the routing
table. Those routes that match the policy are advertised into LDP. You can control the
set of neighbors to which those prefixes are advertised by using the export statement.
Only from operators are considered; you can use any valid from operator. For more
information, see the Junos OS Routing Protocols Configuration Guide.
Example: Configuring the Prefixes Advertised into LDP
Advertise all connected routes into LDP:
[edit protocols]
ldp {
egress-policy connected-only;
}
policy-options {
policy-statement connected-only {
from {
protocol direct;
}
then accept;
}
}
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Configuring FEC Deaggregation
When an LDP egress router advertises multiple prefixes, the prefixes are bound to a single
label and aggregated into a single forwarding equivalence class (FEC). By default, LDP
maintains this aggregation as the advertisement traverses the network.
By default, because an LSP cannot be split across multiple next hops and all the prefixes
are bound into a single LSP, you cannot load-balance across equal-cost paths.
To change the default to load-balance across equal-cost paths, you need to deaggregate
the FECs. Deaggregating the FECs causes each prefix to be bound to a separate label
and become a separate LSP.
To configure deaggregated FECs, include the deaggregate statement:
deaggregate;
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
For all LDP sessions, you can configure deaggregated FECs only globally.
Deaggregating a FEC allows the resulting multiple LSPs to be distributed across multiple
equal-cost paths and distributes LSPs across the multiple next hops on the egress
segments but installs only one next hop per LSP.
To aggregate FECs, include the no-deaggregate statement:
no-deaggregate;
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
For all LDP sessions, you can configure aggregated FECs only globally.
Configuring Policers for LDP FECs
You can configure the Junos OS to track and police traffic for LDP FECs. LDP FEC policers
can be used to do any of the following:
•
Track or police the ingress traffic for an LDP FEC.
•
Track or police the transit traffic for an LDP FEC.
•
Track or police LDP FEC traffic originating from a specific forwarding class.
•
Track or police LDP FEC traffic originating from a specific virtual routing and forwarding
(VRF) site.
•
Discard false traffic bound for a specific LDP FEC.
To police traffic for an LDP FEC, you must first configure a filter. Specifically, you need
to configure either the interface statement or the interface-set statement at the [edit
firewall family protocol-family filter filter-name term term-name from] hierarchy level. The
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interface statement allows you to match the filter to a single interface. The interface-set
statement allows you to match the filter to multiple interfaces.
For more information on how to configure the interface statement, the interface-set
statement, and policers for LDP FECs, see the Junos OS Routing Policy Configuration Guide.
Once you have configured the filters, you need to include them in the policing statement
configuration for LDP. To configure policers for LDP FECs, include the policing statement:
policing {
fec fec-address {
ingress-traffic filter-name;
transit-traffic filter-name;
}
}
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
The policing statement includes the following options:
•
fec—Specify the FEC address for the LDP FEC you want to police.
•
ingress-filter—Specify the name of the ingress traffic filter.
•
transit-traffic—Specify the name of the transit traffic filter.
Configuring LDP IPv4 FEC Filtering
By default, when a targeted LDP session is established, the Junos OS always exchanges
both the IPv4 forwarding equivalence classes (FECs) and the Layer 2 circuit FECs over
the targeted LDP session. For an LDP session to an indirectly connected neighbor, you
might only want to export Layer 2 circuit FECs to the neighbor if the session was
specifically configured to support Layer 2 circuits or VPLS.
In a mixed vendor network where all non-BGP prefixes are advertised into LDP, the LDP
database can become large. For this type of environment, it can be useful to prevent the
advertisement of IPv4 FECs over LDP sessions formed because of Layer 2 circuit or LDP
VPLS configuration. Similarly, it can be useful to filter any IPv4 FECs received in this sort
of environment.
If all the LDP neighbors associated with an LDP session are Layer 2 only, you can configure
the Junos OS to advertise only Layer 2 circuit FECs by configuring the l2-smart-policy
statement. This feature also automatically filters out the IPv4 FECs received on this
session. If you have configured an explicit export or import policy, this feature is disabled.
If one of the LDP session’s neighbors is formed because of a discovered adjacency or if
the adjacency is formed because of an LDP tunneling configuration on one or more RSVP
LSPs, the IPv4 FECs are advertised and received using the default behavior.
To prevent LDP from exporting IPv4 FECs over LDP sessions with Layer 2 neighbors only
and to filter out IPv4 FECs received over such sessions, include the l2-smart-policy
statement:
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l2-smart-policy;
For a list of hierarchy levels at which you can configure this statement, see the statement
summary for this statement.
Configuring BFD for LDP LSPs
You can configure Bidirectional Forwarding Detection (BFD) for LDP LSPs. The BFD
protocol is a simple hello mechanism that detects failures in a network. Hello packets
are sent at a specified, regular interval. A neighbor failure is detected when the router
stops receiving a reply after a specified interval. BFD works with a wide variety of network
environments and topologies. The failure detection timers for BFD have shorter time
limits than the failure detection mechanisms of static routes, providing faster detection.
An error is logged whenever a BFD session for a path fails. The following shows how BFD
for LDP LSP log messages might appear:
RPD_LDP_BFD_UP: LDP BFD session for FEC 10.255.16.14/32 is up
RPD_LDP_BFD_DOWN: LDP BFD session for FEC 10.255.16.14/32 is down
You can also configure BFD for RSVP LSPs, as described in “Configuring BFD for
RSVP-Signaled LSPs” on page 234.
To enable BFD for LDP LSPs, include the oam and bfd-liveness-detection statements:
oam {
bfd-liveness-detection {
detection-time threshold milliseconds;
ecmp;
failure-action {
remove-nexthop;
remove-route;
}
holddown-interval seconds;
ingress-policy ingress-policy-name;
minimum-interval milliseconds;
minimum-receive-interval milliseconds;
minimum-transmit-interval milliseconds;
multiplier detection-time-multiplier;
no-adaptation;
transmit-interval {
minimum-interval milliseconds;
threshold milliseconds;
}
}
fec fec-address;
lsp-ping-interval seconds;
periodic-traceroute {
disable;
exp exp-value;
fanout fanout-value;
frequency minutes;
paths number-of-paths;
retries retry-attempts;
source address;
ttl ttl-value;
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wait seconds;
}
}
You can enable BFD for the LDP LSPs associated with a specific forwarding equivalence
class (FEC) by configuring the FEC address using the fec option at the [edit protocols
ldp] hierarchy level. Alternatively, you can configure an Operation Administration and
Management (OAM) ingress policy to enable BFD on a range of FEC addresses. For more
information, see “Configuring OAM Ingress Policies for LDP” on page 451.
You cannot enable BFD LDP LSPs unless their equivalent FEC addresses are explicitly
configured or OAM is enabled on the FECs using an OAM ingress policy. If BFD is not
enabled for any FEC addresses, the BFD session will not come up.
You can configure the oam statement at the following hierarchy levels:
•
[edit protocols ldp]
•
[edit logical-systems logical-system-name protocols ldp]
The oam statement includes the following options:
•
fec—Specify the FEC address. You must either specify a FEC address or configure an
OAM ingress policy to ensure that the BFD session comes up.
•
lsp-ping-interval—Specify the duration of the LSP ping interval in seconds. To issue a
ping on an LDP-signaled LSP, use the ping mpls ldp command. For more information,
see the Junos OS System Basics and Services Command Reference.
The bfd-liveness-detection statement includes the following options:
•
ecmp—Cause LDP to establish BFD sessions for all ECMP paths configured for the
specified FEC. If you configure the ecmp option, you must also configure the
periodic-traceroute statement for the specified FEC. If you do not do so, the commit
operation fails. You can configure the periodic-traceroute statement at the global
hierarchy level ([edit protocols ldp oam]) while only configuring the ecmp option for a
specific FEC ([edit protocols ldp oam fec address bfd-liveness-detection]).
•
holddown-interval—Specify the duration the BFD session should remain up before
adding the route or next hop. Specifying a time of 0 seconds causes the route or next
hop to be added as soon as the BFD session comes back up.
•
minimum-interval—Specify the minimum transmit and receive interval. If you configure
the minimum-interval option, you do not need to configure the minimum-receive-interval
option or the minimum-transmit-interval option.
•
minimum-receive-interval—Specify the minimum receive interval. The range is from 1
through 255,000 milliseconds.
•
minimum-transmit-interval—Specify the minimum transmit interval. The range is from
1 through 255,000 milliseconds.
•
multiplier—Specify the detection time multiplier. The range is from 1 through 255.
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Configuring ECMP-Aware BFD for LDP LSPs
When you configure BFD for a FEC, a BFD session is established for only one active local
next-hop for the router. However, you can configure multiple BFD sessions, one for each
FEC associated with a specific equal-cost multipath (ECMP) path. For this to function
properly, you also need to configure LDP LSP periodic traceroute. (See “Configuring LDP
LSP Traceroute” on page 451.) LDP LSP traceroute is used to discover ECMP paths. A BFD
session is initiated for each ECMP path discovered. Whenever a BFD session for one of
the ECMP paths fails, an error is logged.
LDP LSP traceroute is run periodically to check the integrity of the ECMP paths. The
following might occur when a problem is discovered:
•
If the latest LDP LSP traceroute for a FEC differs from the previous traceroute, the BFD
sessions associated with that FEC (the BFD sessions for address ranges that have
changed from previous run) are brought down and new BFD sessions are initiated for
the destination addresses in the altered ranges.
•
If the LDP LSP traceroute returns an error (for example, a timeout), all the BFD sessions
associated with that FEC are torn down.
To configure LDP to establish BFD sessions for all ECMP paths configured for the specified
FEC, include the ecmp statement.
ecmp;
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
Along with the ecmp statement, you must also include the periodic-traceroute statement,
either in the global LDP OAM configuration (at the [edit protocols ldp oam] or [edit
logical-systems logical-system-name protocols ldp oam] hierarchy level) or in the
configuration for the specified FEC (at the [edit protocols ldp oam fec address] or [edit
logical-systems logical-system-name protocols ldp oam fec address] hierarchy level).
Otherwise, the commit operation fails.
Configuring a Failure Action for the BFD Session on an LDP LSP
You can configure route and next-hop properties in the event of a BFD session failure
event on an LDP LSP. The failure event could be an existing BFD session that has gone
down or could be a BFD session that never came up. LDP adds back the route or next
hop when the relevant BFD session comes back up.
You can configure one of the following failure action options for the failure-action
statement in the event of a BFD session failure on the LDP LSP:
•
remove-nexthop—Removes the route corresponding to the next hop of the LSP's route
at the ingress node when a BFD session failure event is detected.
•
remove-route—Removes the route corresponding to the LSP from the appropriate
routing tables when a BFD session failure event is detected. If the LSP is configured
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with ECMP and a BFD session corresponding to any path goes down, the route is
removed.
To configure a failure action in the event of a BFD session failure on an LDP LSP, include
either the remove-nexthop option or the remove-route option for the failure-action
statement:
failure-action {
remove-nexthop;
remove-route;
}
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
Configuring the Holddown Interval for the BFD Session
You can specify the duration the BFD session should be up before adding a route or next
hop by configuring the holddown-interval statement at either the [edit protocols ldp oam
bfd-livenesss-detection] hierarchy level or at the [edit protocols ldp oam fec address
bfd-livenesss-detection] hierarchy level. Specifying a time of 0 seconds causes the route
or next hop to be added as soon as the BFD session comes back up.
holddown-interval seconds;
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
Configuring OAM Ingress Policies for LDP
Using the ingress-policy statement, you can configure an Operation, Administration, and
Management (OAM) policy to choose which forwarding equivalence classes (FECs) need
to have OAM enabled. If the FEC passes through the policy or if the FEC is explicitly
configured, OAM is enabled for a FEC. For FECs chosen using a policy, the BFD parameters
configured under [edit protocols ldp oam bfd-liveness-detection] are applied.
You configure the OAM ingress policy at the [edit policy-options] hierarchy level. To
configure an OAM ingress policy, include the ingress-policy statement:
ingress-policy ingress-policy-name;
You can configure this statement at the following hierarchy levels:
•
[edit protocols ldp oam]
•
[edit logical-systems logical-system-name protocols ldp oam]
Configuring LDP LSP Traceroute
You can trace the route followed by an LDP-signaled LSP. LDP LSP traceroute is based
on RFC 4379, Detecting Multi-Protocol Label Switched (MPLS) Data Plane Failures. This
feature allows you to periodically trace all paths in a FEC. The FEC topology information
is stored in a database accessible from the CLI.
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A topology change does not automatically trigger a trace of an LDP LSP. However, you
can manually initiate a traceroute. If the traceroute request is for an FEC that is currently
in the database, the contents of the database are updated with the results.
The periodic traceroute feature applies to all FECs specified by the oam statement
configured at the [edit protocols ldp] hierarchy level. To configure periodic LDP LSP
traceroute, include the periodic-traceroute statement:
periodic-traceroute {
disable;
exp exp-value;
fanout fanout-value;
frequency minutes;
paths number-of-paths;
retries retry-attempts;
source address;
ttl ttl-value;
wait seconds;
}
You can configure this statement at the following hierarchy levels:
•
[edit protocols ldp oam]
•
[edit protocols ldp oam fec address]
The periodic-traceroute statement includes the following options:
•
exp—Specify the class of service to use when sending probes.
•
fanout—Specify the maximum number of next hops to search per node.
•
frequency—Specify the interval between traceroute attempts.
•
paths—Specify the maximum number of paths to search.
•
retries—Specify the number of attempts to send a probe to a specific node before
giving up.
•
source—Specify the IPv4 source address to use when sending probes.
•
ttl—Specify the maximum time-to-live value. Nodes that are beyond this value are not
traced.
•
wait—Specify the wait interval before resending a probe packet.
Collecting LDP Statistics
LDP traffic statistics show the volume of traffic that has passed through a particular FEC
on a router.
When you configure the traffic-statistics statement at the [edit protocols ldp] hierarchy
level, the LDP traffic statistics are gathered periodically and written to a file. You can
configure how often statistics are collected (in seconds) by using the interval option. The
default collection interval is 5 minutes. You must configure an LDP statistics file; otherwise,
LDP traffic statistics are not gathered. If the LSP goes down, the LDP statistics are reset.
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To collect LDP traffic statistics, include the traffic-statistics statement:
traffic-statistics {
file filename <files number> <size size> <world-readable | no-world-readable>;
interval interval;
no-penultimate-hop;
}
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
This section includes the following topics:
•
LDP Statistics Output on page 453
•
Disabling LDP Statistics on the Penultimate-Hop Router on page 454
•
LDP Statistics Limitations on page 454
LDP Statistics Output
The following sample output is from an LDP statistics file:
FEC
10.255.350.448/32
Type
Packets
Bytes
Shared
Transit
0
0
No
Ingress
0
0
No
10.255.350.450/32
Transit
0
0
Yes
Ingress
0
0
No
10.255.350.451/32
Transit
0
0
No
Ingress
0
0
No
220.220.220.1/32
Transit
0
0
Yes
Ingress
0
0
No
220.220.220.2/32
Transit
0
0
Yes
Ingress
0
0
No
220.220.220.3/32
Transit
0
0
Yes
Ingress
0
0
No
May 28 15:02:05, read 12 statistics in 00:00:00 seconds
The LDP statistics file includes the following columns of data:
•
Bytes—Number of bytes of data passed by the FEC since its LSP came up.
•
FEC—FEC for which LDP traffic statistics are collected.
•
Packets—Number of packets passed by the FEC since its LSP came up.
•
read—This number (which appears next to the date and time) might differ from the
actual number of the statistics displayed. Some of the statistics are summarized before
being displayed.
•
Shared—A Yes value indicates that several prefixes are bound to the same label (for
example, when several prefixes are advertised with an egress policy). The LDP traffic
statistics for this case apply to all the prefixes and should be treated as such.
•
Type—Type of traffic originating from a router, either Ingress (originating from this
router) or Transit (forwarded through this router).
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Disabling LDP Statistics on the Penultimate-Hop Router
Gathering LDP traffic statistics at the penultimate-hop router can consume excessive
system resources, on next-hop routes in particular. This problem is exacerbated if you
have configured the deaggregate statement in addition to the traffic-statistics statement.
For routers reaching their limit of next-hop route usage, we recommend configuring the
no-penultimate-hop option for the traffic-statistics statement:
traffic-statistics {
no-penultimate-hop;
}
For a list of hierarchy levels at which you can configure the traffic-statistics statement,
see the statement summary section for this statement.
NOTE: When you configure the no-penultimate-hop option, no statistics are
available for the FECs that are the penultimate hop for this router.
Whenever you include or remove this option from the configuration, the LDP
sessions are taken down and then restarted.
The following sample output is from an LDP statistics file showing routers on which the
no-penultimate-hop option is configured:
FEC
10.255.245.218/32
10.255.245.221/32
13.1.1.0/24
13.1.3.0/24
Type
Transit
Ingress
Transit
Ingress
Transit
Ingress
Transit
Ingress
Packets
0
4
statistics disabled
statistics disabled
statistics disabled
statistics disabled
statistics disabled
statistics disabled
Bytes
0
246
Shared
No
No
LDP Statistics Limitations
The following are issues related to collecting LDP statistics by configuring the
traffic-statistics statement:
•
You cannot clear the LDP statistics.
•
If you shorten the specified interval, a new LDP statistics request is issued only if the
statistics timer expires later than the new interval.
•
A new LDP statistics collection operation cannot start until the previous one has
finished. If the interval is short or if the number of LDP statistics is large, the time gap
between the two statistics collections might be longer than the interval.
When an LSP goes down, the LDP statistics are reset.
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Tracing LDP Protocol Traffic
The following sections describe how to configure the trace options to examine LDP
protocol traffic:
•
Tracing LDP Protocol Traffic at the Protocol and Routing Instance Levels on page 455
•
Tracing LDP Protocol Traffic Within FECs on page 456
•
Examples: Tracing LDP Protocol Traffic on page 456
Tracing LDP Protocol Traffic at the Protocol and Routing Instance Levels
To trace LDP protocol traffic, you can specify options in the global traceoptions statement
at the [edit routing-options] hierarchy level, and you can specify LDP-specific options by
including the traceoptions statement:
traceoptions {
file filename <files number> <size size> <world-readable | no-world-readable>;
flag flag <flag-modifier> <disable>;
}
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
Use the file statement to specify the name of the file that receives the output of the
tracing operation. All files are placed in the directory /var/log. We recommend that you
place LDP-tracing output in the file ldp-log.
The following trace flags display the operations associated with the sending and receiving
of various LDP messages. Each can carry one or more of the following modifiers:
•
address—Trace the operation of address and address withdrawal messages.
•
binding—Trace label-binding operations.
•
error—Trace error conditions.
•
event—Trace protocol events.
•
initialization—Trace the operation of initialization messages.
•
label—Trace the operation of label request, label map, label withdrawal, and label
release messages.
•
notification—Trace the operation of notification messages.
•
packets—Trace the operation of address, address withdrawal, initialization, label
request, label map, label withdrawal, label release, notification, and periodic messages.
This modifier is equivalent to setting the address, initialization, label, notification, and
periodic modifiers.
•
path—Trace label-switched path operations.
•
periodic—Trace the operation of hello and keepalive messages.
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•
route—Trace the operation of route messages.
•
state—Trace protocol state transitions.
Tracing LDP Protocol Traffic Within FECs
You can trace LDP protocol traffic within a specific FEC. You can filter LDP trace
statements based on a FEC. The following trace flags are available for this purpose: route,
path, and binding.
The following example illustrates how you might configure the LDP traceoptions statement
to filter LDP trace statements based on a FEC:
[edit protocols ldp traceoptions]
flag route filter match-on fec policy "filter-policy-for-ldp-fec";
This feature has the following limitations:
•
The filtering capability is only available for FECs composed of IP version 4 (IPv4)
prefixes.
•
Layer 2 circuit FECs cannot be filtered.
•
When you configure both route tracing and filtering, MPLS routes are not displayed
(they are blocked by the filter).
•
Filtering is determined by the policy and the configured value for the match-on option.
When configuring the policy, be sure that the default behavior is always reject.
•
The only match-on option is fec. Consequently, the only type of policy you should
include is a route-filter policy.
Examples: Tracing LDP Protocol Traffic
Trace LDP path messages in detail:
[edit]
protocols {
ldp {
traceoptions {
file ldp size 10m files 5;
flag path;
}
}
}
Trace all LDP outgoing messages:
[edit]
protocols {
ldp {
traceoptions {
file ldp size 10m files 5;
flag packets;
}
}
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}
Trace all LDP error conditions:
[edit]
protocols {
ldp {
traceoptions {
file ldp size 10m files 5;
flag error;
}
}
}
Trace all LDP incoming messages and all label-binding operations:
[edit]
protocols {
ldp {
traceoptions {
file ldp size 10m files 5 world-readable;
flag packets receive;
flag binding;
}
interface all {
}
}
}
Configuring Miscellaneous LDP Properties
The following sections describe how to configure a number of miscellaneous LDP
properties:
•
Configuring LDP to Use the IGP Route Metric on page 458
•
Preventing Addition of Ingress Routes to the inet.0 Routing Table on page 458
•
Multiple-Instance LDP and Carrier-of-Carriers VPNs on page 458
•
Configuring MPLS and LDP to Pop the Label on the Ultimate-Hop Router on page 458
•
Enabling LDP over RSVP-Established LSPs on page 459
•
Enabling LDP over RSVP-Established LSPs in Heterogeneous Networks on page 459
•
Configuring the TCP MD5 Signature for LDP Sessions on page 460
•
Configuring LDP Session Protection on page 461
•
Disabling SNMP Traps for LDP on page 461
•
Configuring LDP Synchronization with the IGP on LDP Links on page 461
•
Configuring LDP Synchronization with the IGP on the Router on page 462
•
Configuring the Label Withdrawal Timer on page 462
•
Ignoring the LDP Subnet Check on page 463
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Configuring LDP to Use the IGP Route Metric
Use the track-igp-metric statement if you want the interior gateway protocol (IGP) route
metric to be used for the LDP routes instead of the default LDP route metric (the default
LDP route metric is 1).
To use the IGP route metric, include the track-igp-metric statement:
track-igp-metric;
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
Preventing Addition of Ingress Routes to the inet.0 Routing Table
By configuring the no-forwarding statement, you can prevent ingress routes from being
added to the inet.0 routing table instead of the inet.3 routing table even if you enabled
the traffic-engineering bgp-igp statement at the [edit protocols mpls] or the [edit
logical-systems logical-system-name protocols mpls] hierarchy level. By default, the
no-forwarding statement is disabled.
To omit ingress routes from the inet.0 routing table, include the no-forwarding statement:
no-forwarding;
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
Multiple-Instance LDP and Carrier-of-Carriers VPNs
By configuring multiple LDP routing instances, you can use LDP to advertise labels in a
carrier-of-carriers VPN from a service provider provider edge (PE) router to a customer
carrier customer edge (CE) router. This is especially useful when the carrier customer is
a basic Internet service provider (ISP) and wants to restrict full Internet routes to its PE
routers. By using LDP instead of BGP, the carrier customer shields its other internal routers
from the Internet. Multiple-instance LDP is also useful when a carrier customer wants to
provide Layer 2 or Layer 3 VPN services to its customers.
For an example of how to configure multiple LDP routing instances for carrier-of-carriers
VPNs, see the Multiple Instances for Label Distribution Protocol Feature Guide.
Configuring MPLS and LDP to Pop the Label on the Ultimate-Hop Router
The default advertised label is label 3 (Implicit Null label). If label 3 is advertised, the
penultimate-hop router removes the label and sends the packet to the egress router. If
ultimate-hop popping is enabled, label 0 (IPv4 Explicit Null label) is advertised.
Ultimate-hop popping ensures that any packets traversing an MPLS network include a
label.
To configure ultimate-hop popping, include the explicit-null statement:
explicit-null;
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For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
NOTE: Juniper Networks routers queue packets based on the incoming label.
Routers from other vendors might queue packets differently. Keep this in
mind when working with networks containing routers from multiple vendors.
For more information about labels, see “Label Description” on page 27 and “Label
Allocation” on page 28.
Enabling LDP over RSVP-Established LSPs
You can run LDP over LSPs established by RSVP, effectively tunneling the LDP-established
LSP through the one established by RSVP. To do so, enable LDP on the lo0.0 interface
(see “Enabling and Disabling LDP” on page 434). You must also configure the LSPs over
which you want LDP to operate by including the ldp-tunneling statement at the [edit
protocols mpls label-switched-path lsp-name] hierarchy level:
[edit]
protocols {
mpls {
label-switched-path lsp-name {
from source;
to destination;
ldp-tunneling;
}
}
}
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
Related
Documentation
•
Tunneling LDP LSPs in RSVP LSPs Overview on page 427
Enabling LDP over RSVP-Established LSPs in Heterogeneous Networks
Some other vendors use an OSPF metric of 1 for the loopback address. Juniper Networks
routers use an OSPF metric of 0 for the loopback address. This might require that you
manually configure the RSVP metric when deploying LDP tunneling over RSVP LSPs in
heterogeneous networks.
When a Juniper Networks router is linked to another vendor’s router through an RSVP
tunnel, and LDP tunneling is also enabled, by default the Juniper Networks router might
not use the RSVP tunnel to route traffic to the LDP destinations downstream of the other
vendor’s egress router if the RSVP path has a metric of 1 larger than the physical OSPF
path.
To ensure that LDP tunneling functions properly in heterogeneous networks, you can
configure OSPF to ignore the RSVP LSP metric by including the ignore-lsp-metrics
statement:
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ignore-lsp-metrics;
You can configure this statement at the following hierarchy levels:
•
[edit protocols ospf traffic-engineering shortcuts]
•
[edit logical-systems logical-system-name protocols ospf traffic-engineering shortcuts]
To enable LDP over RSVP LSPs, you also still need to complete the procedure in “Enabling
LDP over RSVP-Established LSPs” on page 459.
Configuring the TCP MD5 Signature for LDP Sessions
You can configure an MD5 signature for an LDP TCP connection to protect against the
introduction of spoofed TCP segments into LDP session connection streams.
A router using the MD5 signature option is configured with a password for each peer for
which authentication is required. The password is stored encrypted.
LDP hello adjacencies can still be created even when peering interfaces are configured
with different security signatures. However, the TCP session cannot be authenticated
and is never established.
NOTE: If you apply an MD5 signature to an LDP interface with an established
session, it drops the TCP connection and all the associated label bindings to
the FEC entries for that session. The session regenerates the database
information for that session once both interfaces agree on a common security
method and password.
To configure an MD5 signature for an LDP TCP connection, include the session and
authentication-key statement:
session address {
authentication-key md5-authentication-key;
}
For a list of hierarchy levels at which you can include these statements, see the statement
summary section for the session statement.
Use the session statement to configure the address for the remote end of the LDP session.
The md5-authentication-key (password) can be up to 69 characters long. Characters can
include any ASCII strings. If you include spaces, enclose all characters in quotation marks.
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Configuring LDP Session Protection
An LDP session is normally created between a pair of routers that are connected by one
or more links. The routers form one hello adjacency for every link that connects them
and associate all the adjacencies with the corresponding LDP session. When the last
hello adjacency for an LDP session goes away, the LDP session is terminated. You might
want to modify this behavior to prevent an LDP session from being unnecessarily
terminated and reestablished.
You can configure the Junos OS to leave the LDP session between two routers up even
if there are no hello adjacencies on the links connecting the two routers by configuring
the session-protection statement. You can optionally specify a time in seconds using the
timeout option. The session remains up for the duration specified as long as the routers
maintain IP network connectivity.
session-protection {
timeout seconds;
}
For a list of hierarchy levels at which you can include this statement, see the statement
summary section.
Disabling SNMP Traps for LDP
Whenever an LDP LSP makes a transition from up to down, or down to up, the router
sends an SNMP trap. However, it is possible to disable the LDP SNMP traps on a router,
logical system, or routing instance.
For information about the LDP SNMP traps and the proprietary LDP MIB, see the Junos
OS Network Management Configuration Guide.
To disable SNMP traps for LDP, specify the trap disable option for the log-updown
statement:
log-updown {
trap disable;
}
For a list of hierarchy levels at which you can include this statement, see the statement
summary section for this statement.
Configuring LDP Synchronization with the IGP on LDP Links
LDP is a protocol for distributing labels in non-traffic-engineered applications. Labels
are distributed along the best path determined by the IGP. If synchronization between
LDP and the IGP is not maintained, the LSP goes down. When LDP is not fully operational
on a given link (a session is not established and labels are not exchanged), the IGP
advertises the link with the maximum cost metric. The link is not preferred but remains
in the network topology.
LDP synchronization is supported only on active point-to-point interfaces and LAN
interfaces configured as point-to-point under the IGP. LDP synchronization is not
supported during graceful restart.
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To advertise the maximum cost metric until LDP is operational for synchronization, include
the ldp-synchronization statement:
ldp-synchronization {
disable;
hold-time seconds;
}
To disable synchronization, include the disable statement. To configure the time period
to advertise the maximum cost metric for a link that is not fully operational, include the
hold-time statement.
For a list of hierarchy levels at which you can configure this statement, see the statement
summary section for this statement.
Configuring LDP Synchronization with the IGP on the Router
You can configure the time the LDP waits before informing the IGP that the LDP neighbor
and session for an interface are operational. For large networks with numerous FECs, you
might need to configure a longer value to allow enough time for the LDP label databases
to be exchanged.
To configure the time the LDP waits before informing the IGP that the LDP neighbor and
session are operational, include the igp-synchronization statement and specify a time in
seconds for the holddown-interval option:
igp-synchronization holddown-interval seconds;
For a list of hierarchy levels at which you can configure this statement, see the statement
summary section for this statement.
Configuring the Label Withdrawal Timer
The label withdrawal timer delays sending a label withdrawal message for a FEC to a
neighbor. When an IGP link to a neighbor fails, the label associated with the FEC has to
be withdrawn from all the upstream routers if the neighbor is the next hop for the FEC.
After the IGP converges and a label is received from a new next hop, the label is
readvertised to all the upstream routers. This is the typical network behavior. By delaying
label withdrawal by a small amount of time (for example, until the IGP converges and
the router receives a new label for the FEC from the downstream next hop), the label
withdrawal and sending a label mapping soon could be avoided. The
label-withdrawal-delay statement allows you to configure this delay time. By default,
the delay is 60 seconds.
If the router receives the new label before the timer runs out, the label withdrawal timer
is canceled. However, if the timer runs out, the label for the FEC is withdrawn from all of
the upstream routers.
By default, LDP waits for 60 seconds before withdrawing labels to avoid resignaling LSPs
multiple times while the IGP is reconverging. To configure the label withdrawal delay
time in seconds, include the label-withdrawal-delay statement:
label-withdrawal-delay seconds;
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Chapter 15: LDP Configuration Guidelines
For a list of hierarchy levels at which you can configure this statement, see the statement
summary section for this statement.
Ignoring the LDP Subnet Check
In Junos OS Release 8.4 and later releases, an LDP source address subnet check is
performed during the neighbor establishment procedure. The source address in the LDP
link hello packet is matched against the interface address. This causes an interoperability
issue with some other vendors’ equipment.
To disable the subnet check, include the allow-subnet-mismatch statement:
allow-subnet-mismatch;
This statement can be included at the following hierarchy levels:
•
[edit protocols ldp interface interface-name]
•
[edit logical-systems logical-system-name protocols ldp interface interface-name]
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CHAPTER 16
Summary of LDP Configuration
Statements
This chapter provides a reference for each LDP configuration statement. The statements
are organized alphabetically.
allow-subnet-mismatch
Syntax
Hierarchy Level
Release Information
allow-subnet-mismatch;
[edit logical-systems logical-system-name protocols ldp interface interface-name],
[edit protocols ldp interface interface-name]
Statement introduced in Junos OS Release 9.3.
Description
Ignore the LDP subnet check. For Junos OS Release 8.4 and later releases, an LDP source
address subnet check was added for the neighbor establishment procedure. The source
address in the LDP link hello packet is matched against the interface address.
Default
The source address in the LDP link hello packet is matched against the interface address.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Ignoring the LDP Subnet Check on page 463
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authentication-key
Syntax
Hierarchy Level
Release Information
Description
Required Privilege
Level
Related
Documentation
466
authentication-key md5-authentication-key;
[edit logical-systems logical-system-name protocols ldp session address],
[edit logical-systems logical-system-name routing-instances routing-instance-name protocols
ldp session address],
[edit protocols ldp session address],
[edit routing-instances routing-instance-name protocols ldp session address]
Statement introduced before Junos OS Release 7.4.
Configure the MD5 authentication signature. The maximum length of the authentication
signature is 69 characters.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the TCP MD5 Signature for LDP Sessions on page 460
Copyright © 2011, Juniper Networks, Inc.
Chapter 16: Summary of LDP Configuration Statements
bfd-liveness-detection
Syntax
Hierarchy Level
Release Information
Description
Options
bfd-liveness-detection {
detection-time threshold milliseconds;
ecmp;
failure-action {
remove-nexthop;
remove-route;
}
holddown-interval seconds;
minimum-interval milliseconds;
minimum-receive-interval milliseconds;
minimum-transmit-interval milliseconds;
multiplier detection-time-multiplier;
no-adaptation;
transmit-interval {
minimum-interval milliseconds;
threshold milliseconds;
}
}
[edit logical-systems logical-system-name protocols ldp oam],
[edit logical-systems logical-system-name protocols ldp oam fec address],
[edit protocols ldp oam],
[edit protocols ldp oam fec address]
Statement introduced in Junos OS Release 7.6.
Support for the bfd-liveness-detection statement at the [edit protocols ldp oam fec
address] hierarchy level and the ecmp option added in Junos OS Release 9.0.
Support for the failure-action statement with the remove-nexthop and remove-route
options and the holddown-interval statement added in Junos OS Release 9.4.
Enable Bidirectional Forwarding Detection (BFD) for all MPLS LSPs or for just a specific
LSP.
minimum-interval—Minimum transmit and receive interval.
Range: 50 through 255,000 milliseconds
Default: 50
minimum-receive-interval—Minimum receive interval.
Range: 50 through 255,000 milliseconds
Default: 50
minimum-transmit-interval—Minimum transmit interval.
Range: 50 through 255,000 milliseconds
Default: 50
multiplier—Detection time multiplier.
Range: 50 through 255
Default: 3
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The other options are explained separately.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring BFD for LDP LSPs on page 448
deaggregate
Syntax
Hierarchy Level
Release Information
Description
Default
Options
deaggregate | no-deaggregate;
[edit logical-systems logical-system-name protocols ldp],
[edit logical-systems logical-system-name routing-instances routing-instance-name protocols
ldp],
[edit protocols ldp],
[edit routing-instances routing-instance-name protocols ldp]
Statement introduced before Junos OS Release 7.4.
Control forwarding equivalence class (FEC) deaggregation on the router.
Deaggregation is disabled on the router.
deaggregate—Deaggregate FECs.
no-deaggregate—Aggregate FECs.
Required Privilege
Level
Related
Documentation
468
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring FEC Deaggregation on page 446
Copyright © 2011, Juniper Networks, Inc.
Chapter 16: Summary of LDP Configuration Statements
disable
Syntax
Hierarchy Level
Release Information
Description
Default
Required Privilege
Level
Related
Documentation
disable;
[edit logical-systems logical-system-name protocols ldp graceful-restart],
[edit logical-systems logical-system-name protocols ldp interface interface-name],
[edit logical-systems logical-system-name routing-instances routing-instance-name protocols
ldp interface interface-name],
[edit logical-systems logical-system-name routing-instances routing-instance-name
routing-options graceful-restart],
[edit protocols ldp graceful-restart],
[edit protocols ldp interface interface-name],
[edit routing-instances routing-instance-name protocols ldp interface interface-name],
[edit routing-instances routing-instance-name routing-options graceful-restart]
Statement introduced before Junos OS Release 7.4.
Explicitly disable LDP on an interface, or explicitly disable LDP graceful restart.
LDP is enabled on interfaces configured with the LDP interface statement. LDP graceful
restart is automatically enabled when graceful restart is enabled under the [edit
routing-options] hierarchy level.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Enabling and Disabling LDP on page 434
•
Configuring LDP Graceful Restart on page 438
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ecmp
Syntax
Hierarchy Level
Release Information
Description
Required Privilege
Level
Related
Documentation
ecmp;
[edit logical-systems logical-system-name protocols ldp oam bfd-liveness-detection],
[edit logical-systems logical-system-name protocols ldp oam fec address
bfd-liveness-detection],
[edit protocols ldp oam bfd-liveness-detection],
[edit protocols ldp oam fec address bfd-liveness-detection]
Statement introduced in Junos OS Release 8.5.
Allows LDP to establish BFD sessions for all ECMP paths configured for the specified
FEC. If you configure the ecmp statement, you must also configure the periodic-traceroute
statement for the specified FEC. If you do not do so, the commit operation fails. You can
configure the periodic-traceroute statement at the global hierarchy level ([edit protocols
ldp oam]) while only configuring the ecmp statement for a specific FEC ([edit protocols
ldp oam fec address bfd-liveness-detection]).
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring ECMP-Aware BFD for LDP LSPs on page 450
egress-policy
Syntax
Hierarchy Level
Release Information
[edit logical-systems logical-system-name protocols ldp],
[edit logical-systems logical-system-name routing-instances routing-instance-name protocols
ldp],
[edit protocols ldp],
[edit routing-instances routing-instance-name protocols ldp]
Statement introduced before Junos OS Release 7.4.
Description
Control the prefixes advertised into LDP.
Default
Only the loopback address is advertised.
Options
Required Privilege
Level
Related
Documentation
470
egress-policy [ policy-names ];
policy-names—Name of one or more routing policies.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Prefixes Advertised into LDP from the Routing Table on page 445
Copyright © 2011, Juniper Networks, Inc.
Chapter 16: Summary of LDP Configuration Statements
explicit-null
Syntax
Hierarchy Level
Release Information
Description
Default
Required Privilege
Level
Related
Documentation
explicit-null;
[edit logical-systems logical-system-name protocols ldp],
[edit logical-systems logical-system-name routing-instances routing-instance-name protocols
ldp],
[edit protocols ldp],
[edit routing-instances routing-instance-name protocols ldp]
Statement introduced before Junos OS Release 7.4.
Advertise label 0 to the egress router of a label-switched path (LSP).
If you do not include the explicit-null statement in the MPLS configuration, label 3 (implicit
null) is advertised.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring MPLS and LDP to Pop the Label on the Ultimate-Hop Router on page 458
export
Syntax
Hierarchy Level
Release Information
Description
Options
Required Privilege
Level
Related
Documentation
export [ policy-names ];
[edit logical-systems logical-system-name protocols ldp],
[edit logical-systems logical-system-name routing-instances routing-instance-name protocols
ldp],
[edit protocols ldp],
[edit routing-instances routing-instance-name protocols ldp]
Statement introduced before Junos OS Release 7.4.
Apply policy filters to outbound LDP label bindings. Filters are applied to all label bindings
from all neighbors.
policy-names—Name of one or more routing policies.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Filtering Outbound LDP Label Bindings on page 442
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failure-action
Syntax
Hierarchy Level
Release Information
failure-action {
remove-nexthop;
remove-route;
}
[edit logical-systems logical-system-name protocols ldp oam bfd-livenesss-detection],
[edit logical-systems logical-system-name protocols ldp oam fec address
bfd-livenesss-detection],
[edit protocols ldp oam bfd-livenesss-detection],
[edit protocols ldp oam fec address bfd-livenesss-detection]
Statement introduced in Junos OS Release 9.4.
Description
Configure route and next-hop properties in the event of a BFD session failure event on
an LDP LSP. The failure event could be an existing BFD session that has gone down or
could be a BFD session that never came up. LDP adds back the route or next hop when
the relevant BFD session comes back up.
Options
remove-nexthop—Remove a route corresponding to a next hop of the LSP’s route at the
ingress node when a BFD session failure event is detected.
remove-route—Remove the route corresponding to an LSP from the appropriate routing
tables when a BFD session failure event is detected. If the LSP is configured with
ECMP and a BFD session corresponding to any path goes down, the route is removed.
Required Privilege
Level
Related
Documentation
472
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring a Failure Action for the BFD Session on an LDP LSP on page 450
Copyright © 2011, Juniper Networks, Inc.
Chapter 16: Summary of LDP Configuration Statements
graceful-restart
Syntax
Hierarchy Level
Release Information
Description
graceful-restart {
disable;
helper-disable;
maximum-neighbor-recovery-time value;
reconnect-time seconds;
recovery-time value;
}
[edit logical-systems logical-system-name protocols ldp],
[edit logical-systems logical-system-name routing-instances routing-instance-name protocols
ldp],
[edit protocols ldp],
[edit routing-instances routing-instance-name protocols ldp]
Statement introduced before Junos OS Release 7.4.
Enable LDP graceful restart on the LDP master protocol instance or for a specific routing
instance.
NOTE: When you alter the graceful restart configuration at either the [edit
routing-options graceful-restart] or [edit protocols ldp graceful-restart] hierarchy
levels, any running LDP session is automatically restarted to apply the graceful
restart configuration. This behavior mirrors the behavior of BGP when you
alter its graceful restart configuration.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring LDP Graceful Restart on page 438
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hello-interval
Syntax
Hierarchy Level
Release Information
Description
Options
hello-interval seconds;
[edit logical-systems logical-system-name protocols ldp interface interface-name],
[edit logical-systems logical-system-name protocols ldp targeted-hello],
[edit logical-systems logical-system-name routing-instances routing-instance-name protocols
ldp interface interface-name],
[edit logical-systems logical-system-name routing-instances routing-instance-name protocols
ldp targeted-hello],
[edit protocols ldp interface interface-name],
[edit protocols ldp targeted-hello],
[edit routing-instances routing-instance-name protocols ldp interface interface-name],
[edit routing-instances routing-instance-name protocols ldp targeted-hello]
Statement introduced before Junos OS Release 7.4.
Support for LDP targeted hellos added in Junos OS Release 9.5.
Control the LDP timer that regulates how often hello messages are sent. You can control
the rate both link hello messages and targeted hello messages are sent depending on
the hierarchy level at which you configure the hello-interval statement.
seconds—Length of time between transmission of hello packets.
Range: 1 through 65,535 seconds
Default: 5 seconds for link hello messages, 15 seconds for targeted hello messages
Required Privilege
Level
Related
Documentation
474
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the LDP Timer for Hello Messages on page 434
Copyright © 2011, Juniper Networks, Inc.
Chapter 16: Summary of LDP Configuration Statements
helper-disable
Syntax
Hierarchy Level
Release Information
Description
Default
Required Privilege
Level
Related
Documentation
helper-disable;
[edit logical-systems logical-system-name protocols ldp graceful-restart],
[edit logical-systems logical-system-name routing-instances routing-instance-name protocols
ldp graceful-restart],
[edit protocols ldp graceful-restart],
[edit routing-instances routing-instance-name protocols ldp graceful-restart]
Statement introduced before Junos OS Release 7.4.
Disable helper mode for LDP graceful restart. When helper mode is disabled, a router
cannot help a neighboring router that is attempting to restart LDP.
Helper mode is enabled by default on all routing protocols (including LDP) that support
graceful restart.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring LDP Graceful Restart on page 438
holddown-interval
Syntax
Hierarchy Level
Release Information
holddown-interval holddown-interval;
[edit logical-systems logical-system-name protocols ldp oam bfd-livenesss-detection],
[edit logical-systems logical-system-name protocols ldp oam fec address
bfd-livenesss-detection],
[edit protocols ldp oam bfd-livenesss-detection],
[edit protocols ldp oam fec address bfd-livenesss-detection]
Statement introduced in Junos OS Release 9.4.
Description
Specify how long the BFD session should be up before adding the route or next hop.
Specifying a time of 0 seconds causes the route or next hop to be added as soon as the
BFD session comes back up.
Options
holddown-interval—Number of seconds the BFD session should remain up before adding
the route or next hop.
Default: 0 seconds
Range: 0 through 65,535 seconds
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Holddown Interval for the BFD Session on page 451
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
hold-time
Syntax
Hierarchy Level
Release Information
Description
Options
hold-time seconds;
[edit logical-systems logical-system-name protocols ldp interface interface-name],
[edit logical-systems logical-system-name protocols ldp targeted-hello],
[edit logical-systems logical-system-name routing-instances routing-instance-name protocols
ldp interface interface-name],
[edit logical-systems logical-system-name routing-instances routing-instance-name protocols
ldp targeted-hello],
[edit protocols ldp interface interface-name],
[edit protocols ldp targeted-hello],
[edit routing-instances routing-instance-name protocols ldp interface interface-name],
[edit routing-instances routing-instance-name protocols ldp targeted-hello]
Statement introduced before Junos OS Release 7.4.
Support for LDP targeted hellos added in Junos OS Release 9.5.
Specify how long an LDP node should wait for a hello message before declaring a neighbor
to be down. This value is sent as part of a hello message so that each LDP node tells its
neighbors how long to wait. You can specify times for both link hello messages and
targeted hello messages depending on the hierarchy level at which you configure the
hold-time statement.
seconds—Hold-time value.
Range: 1 through 65,535 seconds
Default: 15 seconds for link hello messages, 45 seconds for targeted hello messages
Required Privilege
Level
Related
Documentation
476
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Delay Before LDP Neighbors Are Considered Down on page 435
Copyright © 2011, Juniper Networks, Inc.
Chapter 16: Summary of LDP Configuration Statements
ignore-lsp-metrics
Syntax
Hierarchy Level
Release Information
Description
ignore-lsp-metrics;
[edit logical-systems logical-system-name protocols ospf traffic-engineering shortcuts],
[edit protocols ospf traffic-engineering shortcuts]
Statement introduced in Junos OS Release 7.5.
Cause OSPF to ignore the RSVP LSP metric.
Some other vendors use an OSPF metric of 1 for the loopback address. Juniper Networks
routers use an OSPF metric of 0 for the loopback address. This can cause interoperability
problems when you configure LDP tunneling over RSVP LSPs in heterogeneous networks.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Enabling LDP over RSVP-Established LSPs in Heterogeneous Networks on page 459
igp-synchronization
Syntax
Hierarchy Level
Release Information
Description
Options
igp-synchronization holddown-interval seconds;
[edit logical-systems logical-system-name protocols ldp],
[edit logical-systems logical-system-name routing-instances routing-instance-name protocols
ldp],
[edit protocols ldp],
[edit routing-instances routing-instance-name protocols ldp]
Statement introduced in Junos OS Release 9.5.
Configure the time the LDP waits before informing the IGP that the LDP neighbor and
session for an interface are operational. For large networks with numerous FECs, you
might need to configure a longer value to allow enough time for the LDP label databases
to be exchanged.
holddown-interval seconds—Time the LDP waits before informing the IGP that the LDP
neighbor and session for an interface are operational.
Default: 10 seconds
Range: 10 through 60 seconds
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring LDP Synchronization with the IGP on the Router on page 462
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
import
Syntax
Hierarchy Level
Release Information
Description
Options
Required Privilege
Level
Related
Documentation
import [ policy-names ];
[edit logical-systems logical-system-name protocols ldp],
[edit logical-systems logical-system-name routing-instances routing-instance-name protocols
ldp],
[edit protocols ldp],
[edit routing-instances routing-instance-name protocols ldp]
Statement introduced before Junos OS Release 7.4.
Apply policy filters to received LDP label bindings. Filters are applied to all label bindings
from all neighbors.
policy-names—Name of one or more routing policies.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Filtering Inbound LDP Label Bindings on page 440
ingress-policy
Syntax
Hierarchy Level
Release Information
Description
Options
Required Privilege
Level
Related
Documentation
478
ingress-policy [ ingress-policy-names ];
[edit logical-system logical-system-name protocols ldp oam],
[edit protocols ldp oam]
Statement introduced in Junos OS Release 9.4.
Configure an Operation, Administration, and Management (OAM) policy to choose which
forwarding equivalence classes (FECs) need to have OAM enabled. If the FEC passes
through the policy or if the FEC is explicitly configured, OAM is enabled for a FEC. For
FECs chosen using a policy, the BFD parameters configured under [edit protocols ldp oam
bfd-liveness-detection] are applied.
ingress-policy-names—Specify the names of the ingress policies.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring OAM Ingress Policies for LDP on page 451
Copyright © 2011, Juniper Networks, Inc.
Chapter 16: Summary of LDP Configuration Statements
interface
Syntax
Hierarchy Level
Release Information
Description
Default
Options
interface interface-name {
disable;
hello-interval seconds;
hold-time seconds;
transport-address (interface | loopback);
}
[edit logical-systems logical-system-name protocols ldp],
[edit logical-systems logical-system-name routing-instances routing-instance-name protocols
ldp],
[edit protocols ldp],
[edit routing-instances routing-instance-name protocols ldp]
Statement introduced before Junos OS Release 7.4.
Enable LDP on one or more router interfaces.
LDP is disabled on all interfaces.
interface-name—Name of an interface. To configure all interfaces, specify all.
The remaining statements are explained separately.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Enabling and Disabling LDP on page 434
Copyright © 2011, Juniper Networks, Inc.
479
Junos OS 11.4 MPLS Applications Configuration Guide
keepalive-interval
Syntax
Hierarchy Level
Release Information
Description
Options
keepalive-interval seconds;
[edit logical-systems logical-system-name protocols ldp],
[edit logical-systems logical-system-name routing-instances routing-instance-name protocols
ldp],
[edit protocols ldp],
[edit routing-instances routing-instance-name protocols ldp]
Statement introduced before Junos OS Release 7.4.
Set the keepalive interval value.
seconds—Keepalive value.
Range: 1 through 65,535
Default: 10 seconds
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Interval for LDP Keepalive Messages on page 437
keepalive-timeout
Syntax
Hierarchy Level
Release Information
Description
Options
keepalive-timeout seconds;
[edit logical-systems logical-system-name protocols ldp],
[edit logical-systems logical-system-name routing-instances routing-instance-name protocols
ldp],
[edit protocols ldp],
[edit routing-instances routing-instance-name protocols ldp]
Statement introduced before Junos OS Release 7.4.
Set the keepalive timeout value. The keepalive timeout defines the amount of time that
the neighbor LDP node waits before determining that the session has failed.
seconds—Keepalive timeout value.
Range: 1 through 65,535
Default: 30 seconds
Required Privilege
Level
Related
Documentation
480
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the LDP Keepalive Timeout on page 437
Copyright © 2011, Juniper Networks, Inc.
Chapter 16: Summary of LDP Configuration Statements
l2-smart-policy
Syntax
Hierarchy Level
Release Information
Description
Required Privilege
Level
Related
Documentation
l2-smart-policy;
[edit logical-systems logical-system-name protocols ldp],
[edit logical-systems logical-system-name routing-instances routing-instance-name protocols
ldp],
[edit protocols ldp],
[edit routing-instances routing-instance-name protocols ldp]
Statement introduced in Junos OS Release 8.4.
Prevent LDP from exporting IPv4 FECs over sessions with Layer 2 neighbors only. IPv4
FECs received over such sessions are filtered out.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring LDP IPv4 FEC Filtering on page 447
label-withdrawal-delay
Syntax
Hierarchy Level
Release Information
Description
Options
label-withdrawal-delay seconds;
[edit logical-systems logical-system-name protocols ldp],
[edit logical-systems logical-system-name routing-instances routing-instance-name protocols
ldp],
[edit protocols ldp],
[edit routing-instances routing-instance-name protocols ldp]
Statement introduced in Junos OS Release 9.1.
Delay the withdrawal of labels to reduce router workload during IGP convergence.
seconds—Configure the number of seconds to wait before withdrawing labels for the
LDP LSPs.
Default: 60 seconds
Range: 0 through 300 seconds
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring the Label Withdrawal Timer on page 462
Copyright © 2011, Juniper Networks, Inc.
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Junos OS 11.4 MPLS Applications Configuration Guide
ldp
Syntax
Hierarchy Level
Release Information
Description
ldp { ... }
[edit logical-systems logical-system-name protocols],
[edit logical-systems logical-system-name routing-instances routing-instance-name
protocols],
[edit protocols],
[edit routing-instances routing-instance-name protocols]
Statement introduced before Junos OS Release 7.4.
Statement introduced in Junos OS Release 11.1 for EX Series switches.
Enable LDP routing on the router or switch.
You must include the ldp statement in the configuration to enable LDP on the router or
switch.
Default
Required Privilege
Level
Related
Documentation
482
LDP is disabled on the router.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Minimum LDP Configuration on page 434
•
Enabling and Disabling LDP on page 434
Copyright © 2011, Juniper Networks, Inc.
Chapter 16: Summary of LDP Configuration Statements
ldp-synchronization
Syntax
Hierarchy Level
Release Information
Description
Options
Required Privilege
Level
Related
Documentation
ldp-synchronization {
disable;
hold-time seconds;
}
[edit logical-systems logical-system-name protocols ospf interface interface-name],
[edit logical-systems logical-system-name routing-instances routing-instance-name
protocols ospf interface interface-name],
[edit protocols ospf interface interface-name],
[edit routing-instances routing-instance-name protocols ospf interface interface-name]
Statement introduced in Junos OS Release 7.5.
Enable synchronization by advertising the maximum cost metric until LDP is operational
on the link.
The other statements are explained separately.
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring LDP Synchronization with the IGP on LDP Links on page 461
log-updown
Syntax
Hierarchy Level
Release Information
Description
Options
log-updown {
trap disable;
}
[edit logical-systems logical-system-name protocols ldp],
[edit logical-systems logical-system-name routing-instances routing-instance-name protocols
ldp],
[edit protocols ldp],
[edit routing-instances routing-instance-name protocols ldp]
Statement introduced before Junos OS Release 7.4.
Disable LDP traps on the router, logical system, or routing instance.
trap disable—Disable LDP traps.
Default: LDP traps are enabled on the router.
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Disabling SNMP Traps for LDP on page 461
Copyright © 2011, Juniper Networks, Inc.
483
Junos OS 11.4 MPLS Applications Configuration Guide
maximum-neighbor-recovery-time
Syntax
Hierarchy Level
Release Information
Description
Options
maximum-neighbor-recovery-time seconds;
[edit logical-systems logical-system-name protocols ldp graceful-restart],
[edit logical-systems logical-system-name routing-instances routing-instance-name protocols
ldp graceful-restart],
[edit protocols ldp graceful-restart],
[edit routing-instances routing-instance-name protocols ldp graceful-restart]
Statement introduced before Junos OS Release 7.4. Statement changed from
maximum-recovery-time to maximum-neighbor-recovery-time in Junos OS Release 9.1.
Specify the maximum amount of time to wait before giving up an attempt to gracefully
restart.
seconds—Configure the maximum recovery time, in seconds.
Range: 120 through 1800 seconds
Default: 140 seconds
Required Privilege
Level
Related
Documentation
routing—To view this statement in the configuration.
routing-control—To add this statement to the configuration.
•
Configuring Recovery Time and Maximum Recovery Time on page 440
no-deaggregate
See
484
deaggregate.
Copyright © 2011, Juniper Networks, Inc.
Chapter 16: Summary of LDP Configuration Statements
no-forwarding
Syntax
Hierarchy Level
Release Information
Description
Default
Required Privilege
Level
Related
Documentation
no-forwarding;
[edit logical-systems logical-system-name protocols ldp],
[edit logical-systems logical-system-name routing-instances routing-instance-name protocols
ldp],
[edit protocols ldp],
[edit routing-instances rou