US Patent 7486610 Multiple virtual router group optimization

Methods and apparatus to transition between four states that include a new state, a listening state, a standby state, and an active state. A router includes a plurality of virtual ports. The virtual ports include a master virtual port and one or more client virtual ports. In general, a selected one of the transitions is initiated after occurrence of an event, wherein the initiating of the selected transition is performed only with respect to the master virtual port. When a selected one of the transitions is initiated with respect to the master virtual port of the router, the selected transition is mimicked with respect to the one or more client virtual port(s) of the router.