Question

An MPLS L3VPN service provider has two customer sites for Customer-A connected to PE1 and PE2. The VRF 'CUST-A' on both PEs uses route-distinguisher 65000:100. On PE1 the VRF is configured with 'route-target export 65000:100' and 'route-target import 65000:100'. On PE2 the VRF is configured with 'route-target export 65000:200' and 'route-target import 65000:200'. BGP VPNv4 sessions are up between PE1 and PE2, and both PEs originate their local customer prefixes as VPNv4 routes. However, the customer sites cannot reach each other. What is the most likely cause?

Accepted Answer

The route-target import/export values do not match between the PEs, so neither PE imports the other's VPNv4 routes into the CUST-A VRF

Answer

The route-distinguisher must be unique per PE, and using 65000:100 on both PEs prevents the routes from being installed

Answer

VPNv4 route reflection is required; without an RR the PEs cannot exchange labeled VPN routes directly

Answer

The MP-BGP address-family vpnv4 is not activated, so no VPNv4 prefixes are being advertised at all