Patent attributes
In a system wide network of a hierarchical structure, address allocation is to be managed optimally the system-wide network has a core portion having a static connection pertinence and a terminal portion connected dynamically to the core portion. The upper order server allocates an address block to a lower order server, whilst the lower order server returns the address block to the upper order server. The address allocation in network addition is classed into address allocation phase in the network core portion and an address allocation phase in the network terminal portion. For completing a link for outside with respect to the system-wide network, a representative server acquires its own IP address. The representative server then requests allocation of an address block used in the network terminal portion to its directly higher order server and acquires the so-requested address block. The representative server then executes automatic address allocation processing using e.g., DNCP in the network terminal portion.