Patent ID: 8194684

Claim:
A network apparatus for a wide area network (WAN) connected to an interface device for a local area network (LAN) via a plurality of lines, comprising: a plurality of ports that are connectable to the WAN; a monitoring unit that monitors reception of frames to determine whether the frames are received through the plurality of ports from the interface device for the LAN; a port connecting unit that connects to the WAN a port in the plurality of ports; an active-port selecting unit that selects as an active port the port connected to the WAN by the port connecting unit, when the monitoring unit determines that the frames are received through the plurality of ports from the interface device for the LAN; and a notifying unit that notifies the interface device that a line connected to a port other than the active port selected is in a standby mode, and that a line connected to the active port is in an active mode.