MPLS BGP VPN’s not supported across un-numbered interfaces.
When using an un-numbered interface between PE and P routers instead of IP numbered interfaces, the ERX no longer displays VPN routes and shows the next hop address and unreachable even though ICMP Pings to the next hop address are successful.
Platform: Juniper E-Series
show ip bgp vpn vrf test 192.168.2.0 BGP route information for prefix 192.168.2.0/24 Received route learned from internal peer 184.108.40.206 Route not placed in IP forwarding table Do not advertise to any peers Address Family Identifier (AFI) is ip-v4 Subsequent Address Family Identifier (SAFI) is unicast Route Distinguisher (RD) is 19262:23101 Original Route Distinguisher (RD) is 19262:23010 MPLS in-label is none MPLS out-label is 20 Next hop IP address is 220.127.116.11 (not reachable) Multi-exit discriminator is 0 Local preference is 100 Weight is 0 Origin is Incomplete AS path is empty Extended communities RT:19262:23010
MPLS BGP VPN’s are not supported on un-numbered interfaces. Assigning an IP address to the interface will allow MPLS Tunnels to be built, and display VPN routes correctly.