Patent ID: 7843812

Claim:
A relay apparatus comprising: a media access control (MAC) address learning table to record transfer destinations of frames, the relay apparatus to be connected to a plurality of other relay apparatuses within a network in a ring redundancy configuration; a timer that is started in response to a failure within the network; and, a port moving detection circuit to detect a port move occurring when a frame arrives on a path other than a path within the MAC address learning table, due to a path change within the ring redundancy configuration, wherein the port moving detection circuit is to detect the port move only after the timer has been started in response to the failure within the network, wherein in response to starting of the timer, a MAC address learning table cancellation frame is transferred from the relay apparatus, and wherein the interaction of the MAC address learning table, the timer, and the port move detection circuit prevent a reversal of arrival order of frames, and prevent incorrect learning of the MAC address learning table.