Patent ID: 7787365

Claim:
A method comprising: with a standby control unit of a network device, monitoring routing communications between a primary control unit of the routing device and an external routing device for a routing protocol; prior to failure of the primary control unit, recording the monitored routing communications with the standby control unit of the routing device; after recording the routing communications with the standby control unit and prior to failure of the primary control unit, processing at least a portion of the routing communications with the primary control unit of the routing device to maintain routing information; upon failure of the primary control unit, applying, with the standby control unit, at least one path selection algorithm to select paths through a network; computing, with the standby control unit, a set of new outbound routing communications for the routing protocol resulting from the application of the path selection algorithm; comparing the new outbound routing communications computed by the standby control unit to the recorded routing communications previously output by the primary control unit to determine if any differences exist between the standby control unit and the external routing device; computing, with the standby control unit, a set of incremental routing protocol update communications based on the comparison; and outputting, with the standby control unit, the set of incremental routing protocol update communications to the external routing device to synchronize the standby routing device and the external routing device with respect to the routing protocol.