Graceful Restart: Standard And Interface-Based - Cisco CRS Configuration Manual

Implementing RSVP for MPLS-TE and MPLS O-UNI
The procedure for RSVP graceful restart is described in the "Fault Handling" section of RFC 3473, Generalized
MPLS Signaling, RSVP-TE Extensions. One of the main advantages of using RSVP graceful restart is recovery
of the control plane while preserving nonstop forwarding and existing labels.

Graceful Restart: Standard and Interface-Based

When you configure RSVP graceful restart, Cisco IOS XR software sends and expects node-id address based
Hello messages (that is, Hello Request and Hello Ack messages). The RSVP graceful restart Hello session is
not established if the neighbor router does not respond with a node-id based Hello Ack message.
You can also configure graceful restart to respond (send Hello Ack messages) to interface-address based Hello
messages sent from a neighbor router in order to establish a graceful restart Hello session on the neighbor
router. If the neighbor router does not respond with node-id based Hello Ack message, however, the RSVP
graceful restart Hello session is not established.
Cisco IOS XR software provides two commands to configure graceful restart:
• signalling hello graceful-restart
• signalling hello graceful-restart interface-based
By default, graceful restart is disabled. To enable interface-based graceful restart, you must first enable
Note
standard graceful restart. You cannot enable interface-based graceful restart independently.
Related Topics
Enabling Graceful Restart, on page 125
Enable Graceful Restart: Example, on page 148
Enable Interface-Based Graceful Restart: Example, on page 148
Cisco IOS XR MPLS Configuration Guide for the Cisco CRS Router, Release 5.1.x
Graceful Restart
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