Link protection for MLDP

MLDP link protection enables fast reroute of traffic carried over LDP LSPs in case of a link failure. LDP point-to-multipoint LSPs can be used to send traffic from a single root or ingress node to a number of leaf nodes or egress nodes traversing one or more transit nodes. When one of the links of the point-to-multipoint tree fails, the subtrees might get detached until the IGP reconverges and MLDP initiates label mapping using the best path from the downstream to the new upstream router. To protect the traffic in the event of a link failure, you can configure an explicit tunnel so that traffic can be rerouted using the tunnel. Junos OS supports make-before-break (MBB) capabilities to ensure minimum packet loss when attempting to signal a new LSP path before tearing down the old LSP path. This feature also adds targeted LDP support for MLDP link protection.