Cisco CRS User manual

Cisco IOS XR MPLS Configuration Guide for the Cisco CRS Router,
Release 5.1.x
First Published: February 17, 2014
Last Modified: September 05, 2014
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©2014 Cisco Systems, Inc. All rights reserved.

CONTENTS
Preface Preface xvii
Changes to This Document xvii
Obtaining Documentation and Submitting a Service Request xvii
CHAPTER 1 New and Changed Feature Information in Cisco IOS XR Release 5.1.x 1
New and Changed Feature Information in Cisco IOS XR Release 5.1.x 1
CHAPTER 2 Implementing MPLS Label Distribution Protocol 5
Prerequisites for Implementing Cisco MPLS LDP 6
Information About Implementing Cisco MPLS LDP 7
Overview of Label Distribution Protocol 7
Label Switched Paths 7
LDP Control Plane 7
Exchanging Label Bindings 8
LDP Forwarding 9
LDP Graceful Restart 11
Control Plane Failure 11
Phases in Graceful Restart 12
Recovery with Graceful-Restart 14
Label Advertisement Control (Outbound Filtering) 15
Label Acceptance Control (Inbound Filtering) 15
Local Label Allocation Control 16
Session Protection 16
IGP Synchronization 17
IGP Auto-configuration 18
IGP Synchronization Process Restart Delay 18
LDP Nonstop Routing 19
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IP LDP Fast Reroute Loop Free Alternate 19
Downstream on Demand 21
MPLS LDP Carrier Supporting Carrier for Multiple VRFs 21
MPLS Carrier Supporting Carrier L3VPN: Introduction 21
Benefits of MPLS LDP CSC 22
Multiple VRF Support 23
RSI 23
VRF Table ID Database 23
VRF-Interface Mapping 23
Context Isolation 24
Default Context 24
Restrictions and Recommendations 24
How to Implement MPLS LDP 25
Configuring LDP Discovery Parameters 25
Configuring LDP Discovery Over a Link 27
Configuring LDP Discovery for Active Targeted Hellos 29
Configuring LDP Discovery for Passive Targeted Hellos 32
Configuring Label Advertisement Control (Outbound Filtering) 34
Setting Up LDP Neighbors 36
Setting Up LDP Forwarding 39
Configuring Global Transport Address 42
Setting Up LDP NSF Using Graceful Restart 43
Configuring Label Acceptance Control (Inbound Filtering) 46
Configuring Local Label Allocation Control 48
Configuring Session Protection 49
Configuring LDP IGP Synchronization: OSPF 50
Disabling LDP IGP Synchronization: OSPF 53
Configuring LDP IGP Synchronization: ISIS 55
Configuring LDP IGP Synchronization Delay Interval 56
Configuring LDP IGP Synchronization Process Restart Delay 58
Enabling LDP Auto-Configuration for a Specified OSPF Instance 59
Enabling LDP Auto-Configuration in an Area for a Specified OSPF Instance 61
Disabling LDP Auto-Configuration 62
Configuring LDP Nonstop Routing 63
Configuring LDP Downstream on Demand mode 66
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Redistributing MPLS LDP Routes into BGP 67
Enabling MLDP 69
Enabling MLDP Make-Before-Break 70
Enabling MLDP MoFRR 71
Enabling MLDP Recursive FEC 73
Enabling MLDP Static Multipoint to Multipoint LSP 74
Enabling MLDP Static Point to Multipoint LSP 76
Disabling MLDP 78
Configuration Examples for Implementing MPLS LDP 79
Configuring LDP with Graceful Restart: Example 79
Configuring LDP Discovery: Example 79
Configuring LDP Link: Example 80
Configuring LDP Discovery for Targeted Hellos: Example 80
Configuring Label Advertisement (Outbound Filtering): Example 80
Configuring LDP Neighbors: Example 81
Configuring LDP Forwarding: Example 81
Configuring LDP Nonstop Forwarding with Graceful Restart: Example 82
Configuring Label Acceptance (Inbound Filtering): Example 82
Configuring Local Label Allocation Control: Example 82
Configuring LDP Session Protection: Example 83
Configuring LDP IGP Synchronization—OSPF: Example 83
Configuring LDP IGP Synchronization—ISIS: Example 83
Configuring LDP Auto-Configuration: Example 84
Configure IP LDP Fast Reroute Loop Free Alternate: Examples 84
Verify IP LDP Fast Reroute Loop Free Alternate: Example 86
MPLS LDP CSC for Multiple VRFs Configuration: Examples 88
Additional References 99
CHAPTER 3 Implementing MPLS Static Labeling 101
Enable MPLS Encapsulation on an Interface 102
Define a Range for Static MPLS Labels 103
Setup a Static LSP 104
Allocate Static MPLS Label to an IP Prefix and Configure a LSP 105
Allocate Static MPLS Label for a Specific VRF 107
Verify MPLS Static Bindings 108
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Identify and Clear Label Discrepancy 109
CHAPTER 4 Implementing RSVP for MPLS-TE and MPLS O-UNI 111
Prerequisites for Implementing RSVP for MPLS-TE and MPLS O-UNI 112
Information About Implementing RSVP for MPLS-TE and MPLS O-UNI 112
Overview of RSVP for MPLS-TE and MPLS O-UNI 112
LSP Setup 113
High Availability 114
Graceful Restart 114
Graceful Restart: Standard and Interface-Based 115
Graceful Restart: Figure 116
ACL-based Prefix Filtering 117
RSVP MIB 117
Information About Implementing RSVP Authentication 118
RSVP Authentication Functions 118
RSVP Authentication Design 118
Global, Interface, and Neighbor Authentication Modes 119
Security Association 120
Key-source Key-chain 121
Guidelines for Window-Size and Out-of-Sequence Messages 122
Caveats for Out-of-Sequence 122
How to Implement RSVP 122
Configuring Traffic Engineering Tunnel Bandwidth 123
Confirming DiffServ-TE Bandwidth 123
Configuring MPLS O-UNI Bandwidth 124
Enabling Graceful Restart 125
Configuring ACL-based Prefix Filtering 126
Configuring ACLs for Prefix Filtering 126
Configuring RSVP Packet Dropping 127
Verifying RSVP Configuration 129
Enabling RSVP Traps 132
How to Implement RSVP Authentication 133
Configuring Global Configuration Mode RSVP Authentication 133
Enabling RSVP Authentication Using the Keychain in Global Configuration Mode 133
Configuring a Lifetime for RSVP Authentication in Global Configuration Mode 135
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Configuring the Window Size for RSVP Authentication in Global Configuration Mode 136
Configuring an Interface for RSVP Authentication 137
Specifying the RSVP Authentication Keychain in Interface Mode 137
Configuring a Lifetime for an Interface for RSVP Authentication 139
Configuring the Window Size for an Interface for RSVP Authentication 140
Configuring RSVP Neighbor Authentication 141
Specifying the Keychain for RSVP Neighbor Authentication 142
Configuring a Lifetime for RSVP Neighbor Authentication 143
Configuring the Window Size for RSVP Neighbor Authentication 144
Verifying the Details of the RSVP Authentication 146
Eliminating Security Associations for RSVP Authentication 146
Configuration Examples for RSVP 146
Bandwidth Configuration (Prestandard): Example 146
Bandwidth Configuration (MAM): Example 146
Bandwidth Configuration (RDM): Example 147
Refresh Reduction and Reliable Messaging Configuration: Examples 147
Refresh Interval and the Number of Refresh Messages Configuration: Example 147
Retransmit Time Used in Reliable Messaging Configuration: Example 147
Acknowledgement Times Configuration: Example 147
Summary Refresh Message Size Configuration: Example 148
Disable Refresh Reduction: Example 148
Configure Graceful Restart: Examples 148
Enable Graceful Restart: Example 148
Enable Interface-Based Graceful Restart: Example 148
Change the Restart-Time: Example 149
Change the Hello Interval: Example 149
Configure ACL-based Prefix Filtering: Example 149
Set DSCP for RSVP Packets: Example 149
Enable RSVP Traps: Example 150
Configuration Examples for RSVP Authentication 150
RSVP Authentication Global Configuration Mode: Example 150
RSVP Authentication for an Interface: Example 151
RSVP Neighbor Authentication: Example 151
RSVP Authentication by Using All the Modes: Example 152
Additional References 152
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CHAPTER 5 Implementing MPLS Forwarding 155
Prerequisites for Implementing Cisco MPLS Forwarding 156
Restrictions for Implementing Cisco MPLS Forwarding 156
Information About Implementing MPLS Forwarding 156
MPLS Forwarding Overview 156
Label Switching Functions 157
Distribution of Label Bindings 157
MFI Control-Plane Services 158
MFI Data-Plane Services 158
Time-to-Live Propagation in Hierarchical MPLS 158
MPLS Maximum Transmission Unit 158
How to Implement MPLS Forwarding 158
Configuring the Time-to-Live Propagation in Hierarchical MPLS 159
Configuring the Size of the Local Label 160
Additional References 161
CHAPTER 6 Implementing MPLS Traffic Engineering 163
Prerequisites for Implementing Cisco MPLS Traffic Engineering 165
Information About Implementing MPLS Traffic Engineering 166
Overview of MPLS Traffic Engineering 166
Benefits of MPLS Traffic Engineering 166
How MPLS-TE Works 166
MPLS Traffic Engineering 168
Backup AutoTunnels 168
AutoTunnel Attribute-set 168
Link Protection 169
Node Protection 169
Backup AutoTunnel Assignment 170
Explicit Paths 171
Periodic Backup Promotion 171
Protocol-Based CLI 171
Differentiated Services Traffic Engineering 172
Prestandard DS-TE Mode 172
IETF DS-TE Mode 172
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Bandwidth Constraint Models 173
Maximum Allocation Bandwidth Constraint Model 173
Russian Doll Bandwidth Constraint Model 173
TE Class Mapping 174
Flooding 174
Flooding Triggers 174
Flooding Thresholds 175
Fast Reroute 175
IS-IS IP Fast Reroute Loop-free Alternative 176
MPLS-TE and Fast Reroute over Link Bundles 176
Ignore Intermediate System-to-Intermediate System Overload Bit Setting in MPLS-TE 177
DWDM Transponder Integration 178
GMPLS Benefits 178
GMPLS Support 178
GMPLS Protection and Restoration 179
1:1 LSP Protection 179
Shared Mesh Restoration and M:N Path Protection 179
End-to-end Recovery 180
GMPLS Protection Requirements 180
GMPLS Prerequisites 180
Flexible Name-based Tunnel Constraints 180
MPLS Traffic Engineering Interarea Tunneling 181
Interarea Support 181
Multiarea Support 181
Loose Hop Expansion 182
Loose Hop Reoptimization 183
ABR Node Protection 183
Fast Reroute Node Protection 183
MPLS-TE Forwarding Adjacency 183
MPLS-TE Forwarding Adjacency Benefits 183
MPLS-TE Forwarding Adjacency Restrictions 184
MPLS-TE Forwarding Adjacency Prerequisites 184
Unequal Load Balancing 184
Path Computation Element 185
Policy-Based Tunnel Selection 186
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Policy-Based Tunnel Selection 186
Policy-Based Tunnel Selection Functions 187
PBTS Restrictions 187
Path Protection 188
Pre-requisites for Path Protection 188
Restrictions for Path Protection 189
Restrictions for Explicit Path Protection 189
Co-existence of Path Protection with Fast Reroute 190
MPLS-TE Automatic Bandwidth 190
MPLS-TE Automatic Bandwidth Overview 190
Adjustment Threshold 192
Overflow Detection 192
Underflow Detection 192
Restrictions for MPLS-TE Automatic Bandwidth 193
Point-to-Multipoint Traffic-Engineering 193
Point-to-Multipoint Traffic-Engineering Overview 193
Point-to-Multipoint RSVP-TE 195
Point-to-Multipoint Fast Reroute 196
Point-to-Multipoint Label Switch Path 196
Path Option for Point-to-Multipoint RSVP-TE 196
MPLS Traffic Engineering Shared Risk Link Groups 198
Explicit Path 199
Fast ReRoute with SRLG Constraints 199
Importance of Protection 201
Delivery of Packets During a Failure 202
Multiple Backup Tunnels Protecting the Same Interface 202
SRLG Limitations 202
MPLS TE SRLG Scale Enhancements 203
Soft-Preemption 203
Path Option Attributes 204
Configuration Hierarchy of Path Option Attributes 204
Traffic Engineering Bandwidth and Bandwidth Pools 205
Path Option Switchover 205
Path Option and Path Protection 206
Auto-Tunnel Mesh 206
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