R0106-HP MSR Router Series MPLS Command Reference(V7)

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The graceful-restart command does not take effect on LDP sessions established before the command is
executed. To apply the new setting, execute the reset mpls ldp command to reestablish LDP sessions.
Examples
# Enable GR for LDP.
<Sysname> system-view
[Sysname] mpls ldp
[Sysname-ldp] graceful-restart
Related commands
• display mpls ldp parameter
• reset mpls ldp
graceful-restart timer
Use graceful-restart timer to configure the MPLS Forwarding State Holding timer and the Reconnect timer
for GR.
Use undo graceful-restart timer to restore the default.
Syntax
graceful-restart timer { forwarding-hold hold-time | reconnect reconnect-time }
undo graceful-restart timer { forwarding-hold | reconnect }
Default
The MPLS Forwarding State Holding timer is 180 seconds and the Reconnect timer is 120 seconds.
Views
LDP view
Predefined user roles
network-admin
Parameters
forwarding-hold hold-time: Specifies the MPLS Forwarding State Holding time in the range of 60 to 600
seconds. This time specifies how long the local LSR retains its MPLS forwarding entries after the control
plane of the local LSR restarts.
reconnect timeout: Specifies the Reconnect time in the range of 60 to 300 seconds. This time specifies the
period the local LSR expects the peer to wait for LDP session reestablishment after the peer detects an LDP
session failure. The local LSR sends the Reconnect time to the peer.
Usage guidelines
The MPLS Forwarding State Holding time must be greater than the Reconnect time.
In a GR process, the timers work as follows:
1. When LDP restarts, the GR restarter starts the MPLS Forwarding State Holding timer, and marks the
MPLS forwarding entries as stale. When a GR helper detects that the LDP session to the GR
restarter is down, it performs the following tasks:
a. Marks the FEC-label mappings learned from the session as stale.
b. Starts the Reconnect timer received from the GR restarter.
2. After the LDP restart, the GR restarter reestablishes an LDP session to the GR helper.