Cisco NCS 5500 Series

LDP IGP auto-configuration can also be explicitly disabled on individual interfaces under LDP using the igp
auto-config disable command. This allows LDP to receive all IGP interfaces except the ones explicitly
disabled.
See the MPLS configuration guide for information on configuring LDP IGP auto-configuration.
MPLS LDP-IGP Synchronization Compatibility with LDP Graceful Restart
LDP graceful restart protects traffic when an LDP session is lost. If a graceful restart-enabled LDP session
fails, MPLS LDP IS-IS synchronization is still achieved on the interface while it is protected by graceful
restart. MPLS LDP IGP synchronization is eventually lost under the following circumstances:
• LDP fails to restart before the LDP graceful restart reconnect timer expires.
• The LDP session on the protected interface fails to recover before the LDP graceful restart recovery
timer expires.
MPLS LDP-IGP Synchronization Compatibility with IGP Nonstop Forwarding
IS-IS nonstop forwarding (NSF) protects traffic during IS-IS process restarts and route processor (RP) failovers.
LDP IS-IS synchronization is supported with IS-IS NSF only if LDP graceful restart is also enabled over the
interface. If IS-IS NSF is not enabled, the LDP synchronization state is not retained across restarts and failovers.
Routing Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.3.x
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Implementing IS-IS
MPLS LDP-IGP Synchronization Compatibility with LDP Graceful Restart