A storage device has a wide link in which any one of addresses that a server has is assigned to a plurality of ports that are connected to the server. A change detecting unit detects a change in the state of any port of the ports. When a change is detected, an address acquiring unit acquires the addresses that are assigned to the ports. An address expecting unit and a physical-address acquiring unit, in accordance with the acquired addresses and with identification information for identifying the ports, manage addresses that the plurality of connection-ports-connected-server can possibly have.