Patent attributes
A switch device includes a plurality of communication ports; a switch unit configured to relay a frame, which has been transmitted from a function unit and to which information including an ID of a VLAN is added, to another function unit via a communication port; and a duplication unit configured to, when the diagnosis device is connected to another switch device, duplicate the frame to be relayed via a designated communication port among the plurality of communication ports, and generate a duplicate frame for diagnosis that is a frame obtained by adding, to a duplicate frame obtained through the duplication, specific information indicating that the duplicate frame for diagnosis should be transmitted to the diagnosis device. The switch unit outputs the duplicate frame for diagnosis generated by the duplication unit from a communication port corresponding to the other switch device.
