Supported platforms

Vyatta documentation

Learn how to install, configure, and operate the Vyatta Network Operating System (Vyatta NOS) and Orchestrator, which help drive our virtual networking and physical platforms portfolio.

MPLS LDP-IGP synchronization

MPLS LDP-IGP synchronization provides a means to synchronize LDP and IGPs to minimize MPLS packet loss.

MPLS LDP-IGP synchronization also provides the following benefits:

  • Provides a means to disable LDP-IGP synchronization on interfaces that you do not want enabled
  • Allows you to globally enable LDP-IGP synchronization on each interface associated with an IGP Open Shortest Path First (OSPF)

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

  • Receive Label silence mechanism
  • End Of Lib mechanism (RFC 5919)

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

Figure 1. 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

  • Affects IPv4 metrics only

Configuring MPLS LDP-IGP synchronization

Configuring MPLS LDP-IGP includes the following tasks:

∙ Configuring MPLS LDP-IGP synchronization with OSPF interfaces (required)

∙ Selectively disabling MPLS LDP-IGP synchronization from some OSPF interfaces (optional)

∙ Verifying MPLS LDP-IGP synchronization with OSPF (optional)