Patent ID: 8040872

Claim:
A frame forwarding apparatus for controlling frame forwarding between each user terminal and a network, the frame forwarding apparatus comprising: a plurality of first interface units each accommodating an access channel connected to at least one user terminal; a second interface unit connected to the network; a frame forwarding management table which saves the address of each user terminal or a network apparatus and a connection port ID associated with the address, the connection port ID identifying the first or second interface unit connected to the terminal or the network apparatus; a frame discarding management table which saves an address to be discarded, a target port ID, and the number of discarded frames in association with one another, the address to be discarded indicating that a received frame having the address as a source address will be discarded; a frame forwarding control processing unit for receiving, forwarding, or discarding a frame with reference to the frame forwarding management table and the frame discarding management table; and a processor for executing a table management process for the frame forwarding management table and the frame discarding management table, as prescribed by a management apparatus; the frame forwarding control processing unit receiving a frame from the first or second interface unit; searching an address-to-be-discarded column in the frame discarding management table for the source address of the received frame; if the source address is found, discarding the received frame and incrementing the corresponding number of discarded frames in the frame discarding management table; if the source address of the received frame is not found in the address-to-be-discarded column in the frame discarding management table, searching an address column and a connection port ID column in the frame forwarding management table for a combination of the source address of the received frame and the connection port ID, and, if the combination is not found, adding the source address of the received frame and the receiving port ID to the address column and the connection port ID column of the frame forwarding management table; and searching the address column of the frame forwarding management table for the destination address of the received frame, if the address is found, forwarding the frame to the port found in the corresponding connection port ID field, and, if the address is not found, flooding the frame to ports except the receiving port of the received frame.