Patent ID: 8565236

Claim:
A relay apparatus for relaying communication frames, the relay apparatus comprising: a plurality of communication ports; a frame transmitter configured to transmit an encapsulated frame to a network, the encapsulated frame being generated such that a communication frame received from outside is encapsulated by data containing an address of the relay apparatus, wherein, before encapsulation, the communication frame includes a source address and a destination address; a learned information management unit configured to record learned information that associates a receiving port, an address of another relay apparatus, and a source address specified in another communication frame before encapsulation when said another communication frame, which is encapsulated by data containing the address of the another relay apparatus, is received from the network; and a status monitoring unit configured to check a connection status for the another relay apparatus, wherein said relay apparatus and the network are redundantly connected by a plurality of communication paths to which the plurality of communication ports are connected, wherein, when the destination address specified in the communication frame before encapsulation matches a source address indicated by a specific record of the learned information, the frame transmitter transmits the encapsulated frame to the network via one of the plurality of communication paths without flooding the plurality of communication ports by transmitting the encapsulated frame to the network from the receiving port indicated by said specific record, the address of the another relay apparatus being indicated by the specific record being designated in the encapsulated frame, and wherein, when the learned information management unit detects a change in a frame transmission path in the network, the learned information management unit deletes a record of the learned information associated with the address of the another relay apparatus when a result of checking the connection status indicates abnormality of connection, but does not delete the record of the learned information associated with the another relay apparatus when the result of checking the connection status indicates normalcy of connection.