Patent ID: 8094569

Claim:
A router comprising: a primary interface of a router port, the primary interface on a first physical layer for communication over a primary network segment; a backup interface of the router port, the backup interface on a second physical layer for communication over a backup network segment; a processor coupled to the primary interface and the backup interface; and a memory in communication with the processor, the memory including computer code executable with the processor, wherein the computer code is configured to: determine whether the first physical layer of the primary interface is stable based on energy state changes of the first physical layer during a first time duration, and whether the primary interface is active at an end of a hold count window of a second time duration, wherein the primary interface is stable when the primary interface is usable to exchange information over the primary network segment; communicate using the primary interface of the router port when the primary interface is determined to be stable; and communicate using the backup interface of the router port when the primary interface is determined to be not stable.