US Patent 9391835 Network switch

A network switch is provided which can shorten a time required for switching-over to a backup route when a failure has occurred in a port for which an LAG is set. The network switch includes a failure detection unit for detecting a port failure, and a forced transfer processing unit for, when a failure is detected in a port at a transfer destination as a target in trying to transfer a received unicast frame and when an link aggregation group is set for a plurality of ports including the relevant port at the transfer destination, forcibly transferring the received unicast frame to another port for which the same link aggregation group as that set for the relevant port at the transfer destination is set.