A mobile terminal apparatus (100, 200, 300, 400) comprising: a plurality of interfaces (101, 201, 301, 401), wherein each of the plurality of interfaces is adapted to, when an associated access mechanism thereof is in an active state, obtain a connection to a network using one of a home-address which is assigned to said interface in advance and a care-of-address which is assigned to said interface while said interface is in a domain where the home-address is not available; an instructing section adapted to instruct a setup of a binding of a home-address of a first interface (101-a) of said plurality of interfaces, said first interface losing a connection obtained through a care-of-address of said first interface, and one of a home-address and a care-of-address of a second interface (101-b), of said plurality of interfaces; and a setup section adapted to set up the binding; characterized in that said instructing section comprises: a detecting section adapted to detect the loss of the connection obtained through the care-of-address of said first interface; a searching section adapted to, when the loss of the connection of said first interface is detected, search for at least one interface whose associated access mechanism is in an active state from among said plurality of interfaces; a selecting section adapted to select, based on a predetermined criterion, said second interface from among said at least one interface that has been searched; a deciding section adapted to decide whether or not the selected second interface is present in a domain where the home-address of said second interface is available; and a determining section adapted to determine the home-address of said second interface to be bound to the home-address of said first interface when said second interface is at home, and further adapted to determine the care-of-address of said second interface to be bound to the home-address of said first interface when said second interface is in a foreign domain, based on a result of the decision by said deciding section. a plurality of interfaces (101, 201, 301, 401), wherein each of the plurality of interfaces is adapted to, when an associated access mechanism thereof is in an active state, obtain a connection to a network using one of a home-address which is assigned to said interface in advance and a care-of-address which is assigned to said interface while said interface is in a domain where the home-address is not available; an instructing section adapted to instruct a setup of a binding of a home-address of a first interface (101-a) of said plurality of interfaces, said first interface losing a connection obtained through a care-of-address of said first interface, and one of a home-address and a care-of-address of a second interface (101-b), of said plurality of interfaces; and a setup section adapted to set up the binding; a detecting section adapted to detect the loss of the connection obtained through the care-of-address of said first interface; a searching section adapted to, when the loss of the connection of said first interface is detected, search for at least one interface whose associated access mechanism is in an active state from among said plurality of interfaces; a selecting section adapted to select, based on a predetermined criterion, said second interface from among said at least one interface that has been searched; a deciding section adapted to decide whether or not the selected second interface is present in a domain where the home-address of said second interface is available; and a determining section adapted to determine the home-address of said second interface to be bound to the home-address of said first interface when said second interface is at home, and further adapted to determine the care-of-address of said second interface to be bound to the home-address of said first interface when said second interface is in a foreign domain, based on a result of the decision by said deciding section.