Patent ID: 7352726

Claim:
A communication device adapted to packet communications between a first terminal connected to a first network and a second terminal connected to a second network, said device comprising: a physical address preparing means for preparing a pseudo physical address of said first terminal or that of said second terminal on the basis of a theoretical address without a physical address being assigned to said first terminal or said second terminal, whichever appropriate, and stored in the received ARP (Address Resolution Protocol) packet; a memory means for storing the pseudo physical address prepared by said physical address preparing means; and a packet preparing means for preparing a new packet storing said pseudo physical address memorized in said memory means, wherein said physical address preparing means prepares a pseudo physical address by changing the theoretical address stored in the ARP packet and adding information indicating local address assignment in said first network or said second network, and wherein said pseudo physical address on said memory is erased if said pseudo physical address is not accessed in a predetermined period of time.