Virtual routers within a single physical router share a centralized data plane containing a centralized switch fabric and a plurality of physical network interfaces, each assigned to only one virtual router. Using a logical cut-through device between a pair of virtual routers designated respectively...http://www.google.com/patents/US20040073715?utm_source=gb-gplus-sharePatent US20040073715 - Method to enable routing protocol communication and transit packet forwarding between virtual routers
