mpls ldp sync (IS-IS view)

Use mpls ldp sync to enable LDP-ISIS synchronization.

Use undo mpls ldp sync to disable LDP-ISIS synchronization.

Syntax

mpls ldp sync [ level-1 | level-2 ]

undo mpls ldp sync [ level-1 | level-2 ]

Default

LDP-ISIS synchronization is disabled.

Views

IS-IS view

Predefined user roles

network-admin

Parameters

level-1: Specifies Level-1 of the IS-IS process.

level-2: Specifies Level-2 of the IS-IS process.

Usage guidelines

LDP establishes LSPs based on the IGP optimal route. If LDP is not synchronized with IGP, MPLS traffic forwarding might be interrupted. The LDP-IGP synchronization feature is used to solve the synchronization problem.

After LDP-IGP synchronization is enabled, IGP advertises the actual cost of a link only when LDP convergence on the link is completed. Before LDP is converged, IGP advertises the maximum cost of the link. As a result, the link is visible on the IGP topology, but IGP does not select the link as the optimal route when other links are available. In this way, the device can avoid discarding MPLS packets due to lack of LDP LSP on the optimal route.

LDP-IGP synchronization is not supported for an IS-IS process that belongs to a VPN instance.

If you do not specify any keywords, this command enables LDP-ISIS synchronization for both Level-1 and Level-2.

If you execute this command multiple times, the most recent configuration takes effect. For example, if you execute the mpls ldp sync level-1 command after you execute the mpls ldp sync command, LDP-ISIS synchronization is enabled for Level-1 but disabled for Level-2.

Examples

# Enable LDP-ISIS synchronization for Level-2 of IS-IS process 1.

<Sysname> system-view
[Sysname] isis 1
[Sysname-isis-1] mpls ldp sync level-2

Related commands

display mpls ldp igp sync

igp sync delay

igp sync delay on-restart

mpls ldp igp sync disable