A system communicating data with a mobile node includes a server and a plurality of networks connected to the server. The mobile node moves between the plurality of networks. One of the networks is set as a home network of the mobile node. The server includes a storage circuit that stores, when it is detected that the mobile node has moved from its home network to another network, an IP address of the mobile node and information indicating the network to which the mobile node has moved, in a location management table. The server further includes a communication circuit that, upon receipt of data destined for the mobile node, forwards the received data to the network that is specified by the information stored in the location management table corresponding to the mobile node.