Patent ID: 8000265

Claim:
A computer-implemented method for determining network topology of a virtual private network in Multi Protocol Label Switching (MPLS) based Virtual Private Networks (MPLS/VPNs), the method comprising: obtaining VPN routing and forwarding (VRF) details of at least one virtual private network in Provider Edges routers; determining, from said VRF details, any variation in network configuration; and determining, from said network configuration variation, network topology of the at least one virtual private network based on whether there is a newly created VRF, a modified VRF or a deleted VRF in the VRF details, and wherein determining the network topology of the at least one virtual private network based on the newly created VRF comprises: obtaining intersecting virtual private network details for the VRF from previously discovered virtual private networks; and merging all found virtual private networks and adding the newly created VRF to the merged virtual private network, if the newly created VRF intersecting more than one virtual private network from the previously discovered virtual private networks is found.