Question

A service provider runs MP-BGP for its L3VPN backbone. Two PE routers (PE1 and PE2) both have VRF CUSTOMER-A configured with matching route-targets, but CUSTOMER-A routes learned on PE1 are not appearing in the VRF routing table on PE2. On PE2, the command 'show bgp vpnv4 unicast all' shows the VPNv4 prefixes from PE1 are present in the BGP table but are not imported into the VRF. What is the MOST likely cause?

Accepted Answer

The import route-target configured under the VRF on PE2 does not match the export route-target set by PE1, so the prefixes remain in the BGP table but are not installed in the VRF.

Answer

The route distinguisher on PE1 and PE2 differs, preventing the VPNv4 prefixes from being advertised between PEs.

Answer

MP-BGP is not carrying the VPNv4 address family, so the prefixes cannot be exchanged at all.

Answer

The PE-CE routing protocol on PE2 has not been redistributed into BGP, so the VRF has no routes.