- The customer site network prefix
- The BGP-speaking PE router serving the customer
- The VPN route-target attribute
The later specifications of the BGP MPLS VPNs RFC, RFC4364, in section 7.4, makes a recommendation in the use Route Origin extended communities in order to unambiguously identify CE-layer routers in MPLS VPN topologies. We could add this capability to our process-mplsvpn.py tool by extracting the <extended-community> attribute of the routing table output. This would provide an extra layer in the graph, allowing a user to see which customer networks were at which site, served by which CE.