Abstract: A network switch is provided which can shorten a time required for switching-over to a backup route when a failure has occurred in a port for which an LAG is set. The network switch includes a failure detection unit for detecting a port failure, and a forced transfer processing unit for, when a failure is detected in a port at a transfer destination as a target in trying to transfer a received unicast frame and when an link aggregation group is set for a plurality of ports including the relevant port at the transfer destination, forcibly transferring the received unicast frame to another port for which the same link aggregation group as that set for the relevant port at the transfer destination is set.

Abstract: In a chassis-type network relay device, fault tolerance for the continuity monitoring function of Ethernet (Registered Trademark) OAM is improved. A first management card and a second management card serving as a main management card and a backup management card have continuity monitoring units which generate monitoring frames for checking continuity between devices and transmit the monitoring frames to a given line card, respectively. Each of a plurality of line cards has a transmission source selecting unit which, when having received respective monitoring frames from both management cards, selects one of the monitoring frames and transmits the selected monitoring frame from a given port.

Abstract: A chassis type switch is provided which can shorten a time required for switching-over to a backup route when a failure has occurred in a line card. In a chassis type switch including a plurality of line cards within a chassis, the switch further includes a failure detection unit for detecting a failure in each of the plural line cards, and a forced flooding processing unit included in each of the plural line cards and operating such that when, in trying to transfer a received unicast frame to another line card, a failure is detected in the relevant line card at a transfer destination, the received unicast frame is forcibly transferred to all ports of the own line card other than a reception port thereof and to all other line cards.

Abstract: In a chassis-type network relay device, fault tolerance for the continuity monitoring function of Ethernet (Registered Trademark) OAM is improved. A first management card and a second management card serving as a main management card and a backup management card have continuity monitoring units which generate monitoring frames for checking continuity between devices and transmit the monitoring frames to a given line card, respectively. Each of a plurality of line cards has a transmission source selecting an it which, when having received respective monitoring frames from both management cards, selects one of the monitoring frames and transmits the selected monitoring frame from a given port.

Abstract: A network relay device constituting a network includes a frame determination unit for referencing a protocol identifier contained in a frame from an external network relay device constituting another standard network different from the network, to determine whether or not the frame contains a confirmation frame for network operation, administration or maintenance, and a processing unit for performing operation, administration, or maintenance on the frame, when the frame determination unit determines that the frame is the confirmation frame.

Abstract: A chassis type switch is provided which can shorten a time required for switching-over to a backup route when a failure has occurred in a line card. In a chassis type switch including a plurality of line cards within a chassis, the switch further includes a failure detection unit for detecting a failure in each of the plural line cards, and a forced flooding processing unit included in each of the plural line cards and operating such that when, in trying to transfer a received unicast frame to another line card, a failure is detected in the relevant line card at a transfer destination, the received unicast frame is forcibly transferred to all ports of the own line card other than a reception port thereof and to all other line cards.

Abstract: A network switch is provided which can shorten a time required for switching-over to a backup route when a failure has occurred in a port for which an LAG is set. The network switch includes a failure detection unit for detecting a port failure, and a forced transfer processing unit for, when a failure is detected in a port at a transfer destination as a target in trying to transfer a received unicast frame and when an link aggregation group is set for a plurality of ports including the relevant port at the transfer destination, forcibly transferring the received unicast frame to another port for which the same link aggregation group as that set for the relevant port at the transfer destination is set.

Abstract: A network relay device constituting a network includes a frame determination unit for referencing a protocol identifier contained in a frame from an external network relay device constituting another standard network different from the network, to determine whether or not the frame contains a confirmation frame for network operation, administration or maintenance, and a processing unit for performing operation, administration, or maintenance on the frame, when the frame determination unit determines that the frame is the confirmation frame.