Automatic detection of a similar device at the other end of a wire in a computer network

摘要

Automatic detection by a port of the type of device connected by a cable to the port is accomplished by transmitting a control packet by the device, where the control packet has a nonstandard format. The port examines received packets for the nonstandard format. Upon detection of a packet having the nonstandard format, the port recognizes that the source device of the packet is of a predetermined type which transmits control packets of the nonstandard format. Further, by choosing the nonstandard packet, the port is assured that the source device is attached to the port by a cable. That is, by choosing a nonstandard packet which is not forwarded by a bridge router, the port is assured that the packet has not been forwarded from a remote part of the network.