A technique is disclosed in which an MN (mobile node) 100 notifies, to a CN (correspondent node), home network connection information indicative of whether or not it is currently in connection with a home network which has allocated its own plurality of HoAs (home addresses), an address of each HA (home agent) and an ID of each HA in a state associated with the plurality of HoAs. Based on the information received from the MN, the CN grasps the home network with which the MN is currently in connection and makes an inquiry about the condition of the HA and sets an appropriate HoA, judged on the basis of the grasping result or the inquiry result, as a destination address of a packet to be transmitted to the MN.