LDP shortcut for IGP routes

The LDP shortcut for IGP route resolution feature allows forwarding of packets to IGP learned routes using an LDP LSP. When LDP shortcut is enabled globally, IP packets forwarded over a network IP interface are labeled with the label received from the next-hop for the route and corresponding to the FEC-prefix matching the destination address of the IP packet. In such a case, the routing table has the shortcut next-hop as the best route. If such a LDP FEC does not exist, then the routing table has the regular IP next-hop and regular IP forwarding is performed on the packet.

An egress LER advertises and maintains a FEC, label binding for each IGP learned route. This is performed by the existing LDP fec-originate capability.