A mobility condition determination unit, provided in an MIP controller that manages moving of a communication node, obtains and examines various conditions that have occurred as the communication node is moving, selects an appropriate HoA (e.g., the home address of an MN1) for the current connection situation, and transmits, to a multihoming controller, a notification indicating that a set of the selected HoA and a CoA constitutes appropriate addresses to be used. Upon receiving the notification from the mobility condition determination unit, the multihoming controller transmits, to the MIP controller, an address (Addr2) consonant with the received HoA, and the MIP controller performs packet communication using the HoA or the CoA consonant with the address.