MPLS LDP-IGP Synchronization

MPLS LDP-IGP synchronization also provides the following benefits:

MPLS LDP-IGP synchronization may be enabled on an interface or globally. LDP determines convergence (receipt of all labels) for a link through one of two methods:

The following figure provides an example of LDP-IGP synchronization.

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Example with LDP-IGP synchronization

When the LDP peer is not reachable, the IGP establishes the adjacency to enable the LDP session to be established. When an IGP adjacency is established on a link but LDP-IGP Synchronization is not yet achieved or is lost, the IGP advertises the maximum metric (max-metric) on the link.

Configuration Considerations