Question

An SP engineer is provisioning an Ethernet-over-MPLS point-to-point pseudowire (VPWS) between PE1 and PE3, which are not directly connected and are separated by core router P2. LDP is enabled on all core-facing interfaces for transport label exchange. After configuring the xconnect on both PEs, the pseudowire remains down and no VC label is exchanged between PE1 and PE3. What must be configured to bring up the pseudowire?

Accepted Answer

A targeted LDP (tLDP) session between the PE1 and PE3 loopbacks to exchange the VC (pseudowire) labels

Answer

An RSVP-TE tunnel between PE1 and PE3 so that VC labels can ride inside the TE tunnel

Answer

LDP on the P2 core router configured as a route reflector for label distribution

Answer

Enable MPLS LDP explicit-null on P2 so the VC label is preserved to the egress PE