SUPPORTING VIRTUAL PRIVATE NETWORKS USING A FIRST NETWORK TOPOLOGY FOR FORWARDING AND A SUBSET OF THE FIRST NETWORK TOPOLOGY OR A SMALLER TOPOLOGY FOR SIGNALING

摘要

Virtual Private Networks (VPNs) are supported in which customers may use popular internet gateway protocol (IGPs) without the need to convert such IGPs, running on customer devices to a single protocol, such as the border gateway protocol (BGP). Scaling problems, which might otherwise occur when multiple instances of an IGP flood link state information, are avoided by using a flooding topology which is smaller than a forwarding topology. The flooding topology may be a fully connected sub-set of the forwarding topology.