US Patent 7822034 Path controls apparatus and table updating method

A receiving unit receives a frame from any one of a plurality of ports. When it is determined that there is no entry to which a correspondence relation for a transmission-source address of the received frame can be registered in a management table, a selecting unit detects an indicator bit located at an oldest generation in a bit string obtained by rearranging generation-management bit strings of all entries of the management table, and selects an entry corresponding to the detected indicator bit as an overwriting target entry. An updating unit registers the correspondence relation to the selected overwriting target entry.