Performs L2VPN discovery

In the L2VPN domain, shown in VPWS L2VPN domain discovered by the MPLS Topology Server and VPLS L2VPN domain discovered by the MPLS Topology Server, the MPLS Topology Server discovers VPN objects for L2VPNs, such as VPNs, Forwarders, ForwarderEndpoints, and PseudoWires. For the sake of simplicity, no ForwarderEndpoints are shown in the figures.

Figure 1. VPWS L2VPN domain discovered by the MPLS Topology Server

Figure 2. VPLS L2VPN domain discovered by the MPLS Topology Server

For LDP-signaled L2VPNs, the MPLS Topology Server also discovers targeted LDP adjacencies. (GUID-20A5AE60-9BCE-460A-9BEB-79B724BDDABD.html#GUID-20A5AE60-9BCE-460A-9BEB-79B724BDDABD___MPLS_DISCO_OVERVIEW_87197 presents an example.) A targeted LDP adjacency provides a bidirectional signaling path through which the peering PE devices in an LDP-signaled L2VPN exchange reachability information for the purpose of constructing, advertising, maintaining, or deleting pseudowires.

For BGP-signaled L2VPNs, the MPLS Topology Server also discovers VRFs. In a BGP-signaled L2VPN, every customer site to which a PE device attaches is associated with a VRF.