R3303-HP HSR6800 Routers MPLS Configuration Guide

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5. After the recovery time elapses, the GR helper deletes the FEC-label bindings that are still marked
stale.
6. When the MPLS forwarding state holding timer expires, the GR restarter deletes the label
forwarding entries that are still marked stale.
Configuration prerequisites
Configure MPLS LDP capability on each device acting as the GR restarter or a GR helper. (The device can
act as a GR restarter or a GR helper as needed in the LDP GR process.)
Configuration procedure
The LDP GR feature and the LDP NSR feature are mutually exclusive. Do not configure both features on the
device.
To configure LDP GR:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enter MPLS LDP view.
mpls ldp N/A
3. Enable MPLS LDP GR.
graceful-restart Disabled by default.
4. Set the FT reconnect time.
graceful-restart timer reconnect
timer
Optional.
300 seconds by default.
5. Set the LDP neighbor liveness
time.
graceful-restart timer
neighbor-liveness timer
Optional.
120 seconds by default.
6. Set the LDP recovery time.
graceful-restart timer recovery
timer
Optional.
300 seconds by default.
Gracefully restarting MPLS LDP
To test whether the MPLS LDP GR configuration has taken effect, you can perform graceful restart of MPLS
LDP. During the LDP restart process, you can see whether the packet forwarding path is changed and
whether packet forwarding is interrupted.
The graceful-restart mpls ldp command is intended only for testing the MPLS LDP GR function. It does not
perform active/standby switchover.
To restart MPLS LDP gracefully:
Task Command Remarks
Restart MPLS LDP gracefully. graceful-restart mpls ldp Available in user view.
Configuring LDP NSR
Nonstop routing (NSR) is a mechanism for keeping on data transmission during an active/standby
switchover. In standalone mode, NSR for LDP can back up LDP session information and LSP information
from the active MPU to the standby MPU of a device. In IRF mode, NSR for LDP can back up LDP session
information and LSP information from the global active MPU to the global standby MPU. When a
switchover occurs, the standby MPU can immediately pick up the LDP service, implementing nonstop
data transmission.