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

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Usage guidelines
LDP convergence on a link is completed when the following events occur:
• The local device establishes an LDP session to at least one peer, and the LDP session is already in
Operational state.
• The local device has distributed the label mappings to at least one peer.
If LDP notifies IGP immediately after convergence, MPLS traffic forwarding might be interrupted in one of
the following scenarios:
• LDP peers use the Ordered label distribution control mode. When LDP notifies IGP of the LDP
convergence, the device has not received a label mapping from downstream.
• A large number of label mappings are distributed from downstream. When LDP notifies IGP of the
LDP convergence completion, label advertisement is not completed.
In these scenarios, you must use the igp sync delay command to configure the notification delay. When
LDP convergence on a link is completed, LDP waits a delay time before notifying IGP of the LDP
convergence completion to reduce traffic interruption.
Examples
# Configure a 30-second delay for LDP to notify IGP of the LDP convergence.
<Sysname> system-view
[Sysname] mpls ldp
[Sysname-ldp] igp sync delay 30
Related commands
• igp sync delay on-restart
• mpls ldp igp sync disable
• mpls ldp sync (IS-IS view)
• mpls ldp sync (OSPF view/OSPF area view)
igp sync delay on-restart
Use igp sync delay on-restart to configure the maximum delay for LDP to notify IGP of the LDP-IGP
synchronization status after an LDP restart or an active/standby switchover occurs.
Use undo igp sync delay on-restart to restore the default.
Syntax
igp sync delay on-restart time
undo igp sync delay on-restart
Default
The maximum notification delay is 90 seconds.
Views
LDP view
Predefined user roles
network-admin
Parameters
time: Specifies the maximum notification delay in the range of 60 to 600 seconds.