MPLS Guide
3HE 18686 AAAB TQZZA © 2022 Nokia.
Use subject to Terms available at: www.nokia.com
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4.7.2.3 PCC Behavior..........................................................................................340
4.8 Configuring RSVP-TE LSPs with PCEP Using the CLI ...........................343
4.8.1 PCEP on the PCE Node and the PCC Node...........................................343
4.8.2 MPLS on the PCC Node..........................................................................346
4.9 PCEP Configuration Command Reference .............................................351
4.9.1 Command Hierarchies.............................................................................351
4.9.1.1 PCEP Commands ...................................................................................352
4.9.1.2 Show Commands ....................................................................................352
4.9.2 Command Descriptions ...........................................................................353
4.9.2.1 PCEP Commands ...................................................................................354
4.9.2.2 Show Commands ....................................................................................359
5 Label Distribution Protocol .......................................................367
5.1 Label Distribution Protocol.......................................................................368
5.1.1 LDP and MPLS........................................................................................369
5.1.1.1 BFD for T-LDP.........................................................................................370
5.1.2 LDP Architecture .....................................................................................370
5.1.3 LDP Subsystem Interrelationships ..........................................................371
5.1.3.1 Memory Manager and LDP .....................................................................371
5.1.3.2 Label Manager.........................................................................................371
5.1.3.3 LDP Configuration ...................................................................................372
5.1.3.4 Logger .....................................................................................................373
5.1.3.5 Service Manager .....................................................................................373
5.1.4 Execution Flow ........................................................................................373
5.1.4.1 Initialization..............................................................................................373
5.1.4.2 Session Lifetime ......................................................................................373
5.1.5 Label Exchange.......................................................................................375
5.1.5.1 Implicit Null Label ....................................................................................375
5.1.5.2 Other Reasons for Label Actions.............................................................375
5.1.5.3 Cleanup ...................................................................................................376
5.1.6 LDP Filters...............................................................................................376
5.1.7 LDP FEC Statistics ..................................................................................377
5.1.8 Multi-area and Multi-instance Extensions to LDP....................................377
5.1.9 ECMP Support for LDP ...........................................................................378
5.1.9.1 Label Operations .....................................................................................381
5.1.10 Graceful Restart Helper...........................................................................382
5.1.11 Graceful Handling of Resource Exhaustion.............................................382
5.1.12 LDP Support for Unnumbered Interfaces ................................................383
5.1.13 LDP Fast Reroute (FRR) .........................................................................385
5.1.13.1 ECMP vs FRR .........................................................................................387
5.1.13.2 IGP Shortcuts (RSVP-TE Tunnels) .........................................................387
5.1.13.3 LDP FRR Configuration...........................................................................387
5.1.14 LDP-to-Segment Routing Stitching for IPv4 /32 Prefixes (IS-IS).............388
5.1.14.1 Stitching in the LDP-to-SR Direction .......................................................390
5.1.14.2 Stitching in the SR-to-LDP Direction .......................................................391
5.1.14.3 TTL Propagation and ICMP Tunneling ....................................................393
5.1.15 LDP FRR Remote LFA and TI-LFA Backup Using an SR Tunnel for
IPv4 /32 Prefixes (IS-IS) ..........................................................................393
5.1.15.1 Feature Behavior ....................................................................................394