A communication control method is provided for an encryption processing unit connected to a connection status acquiring unit which is connected to a circuit that transmits packets on a network and acquires the status of a connection to a network for an encrypting device for encrypting the packet, and connected to an expansion card for connecting to the network, based on the network connection status requested and acquired from the connection status acquiring unit by the expansion card each prescribed period of time, by relaying and acquiring the network connection status from the connection status acquiring unit and forcibly notifying the expansion card that the connection status is connected and/or not connected, according to a requirement/criteria.