Disclosed is a technique of, in a network conducting network based local mobility management, suppressing generation of signaling and an increase of processing load on a network entity and preventing a delay. According to this technique, a mobile node (MN 130) receives specific information (a token) including an interface identifier and a binding identifier, for example, from a network side (MAG 120) when connecting therewith first. When the mobile node conducts a handover, the mobile node notifies a next connecting MAG 122 of the token. The MAG receiving the token can judge based on this token whether the connection by the mobile node is due to a handover changing a connection point for a certain interface or due to a new connection using a different interface without making an inquiry to other network nodes.