US Patent 7447149 Virtual interface with active and backup physical interfaces

A network device, such as a router, utilizes a virtual interface to hide the presence of redundant backup physical interfaces from a router control unit. If traffic needs to be redirected from a primary physical interface, the router remaps the virtual interface to the backup physical interface without needing to update routes and select one or more alternative routes due to the need to redirect traffic. Instead, the router control unit redirects network traffic associated with the primary physical interface to the associated backup physical interface. In this manner, delays associated with route updating can be avoided, and a relatively seamless switchover can be achieved from the primary to the backup physical interface.