Question

A PE router (PE1) has VRF CUSTOMER-A configured with an eBGP session to the CE. PE1 successfully learns the CE's routes into the VRF and installs them in the VRF routing table. However, another PE router (PE2) in the same MPLS core never receives these customer prefixes as VPNv4 routes, even though the MP-BGP session between PE1 and PE2 is Established and other VRFs' prefixes exchange correctly. On PE1, 'show bgp vpnv4 unicast all' shows the CUSTOMER-A prefixes present locally. What is the MOST likely cause?

Accepted Answer

The VRF on PE1 is missing a 'route-target export' statement, so the prefixes are not tagged and not advertised as VPNv4 routes

Answer

The MP-BGP session is missing the 'address-family vpnv4' activation for the PE2 neighbor

Answer

The route distinguisher on PE1's VRF is identical to another customer's RD, causing prefix suppression

Answer

PE1 is not running LDP on the core-facing interface, so labels cannot be assigned to the VPNv4 prefixes