Patent ID: 7296090

Claim:
For use in a data network comprising a plurality of nodes capable of communicating with each other, each node coupled to at least one unit of a customer network, a method of providing a plurality of Virtual Private Networks (VPNs) comprising the steps of: maintaining in a first node a VPN reachability information (VRI) database comprising, for each VPN in which at least one unit coupled to the first node is participating, a send list of nodes coupled to at least one unit participating in that VPN; receiving a request to establish participation by a first unit coupled to the first node in a specified VPN; and if the VRI database does not contain a send list for the specified VPN: transmitting VRI for the first unit to all other nodes in the data network; and requesting from all other nodes in the data network transmission of VPN reachability information for all units participating in the specified VPN; otherwise transmitting VRI for the first unit only to nodes on the send list for the specified VPN.