A method and apparatus for discovering paths to other network devices includes
a protocol and network management application that can be executed on network devices.
The Ethernet protocol is used to detects paths to other network devices, knowing
only the Ethernet address of the destination. A discovery protocol is extended
to add hop probe and hop probe reply Type-Length-Value fields in a variable-length
list. The hop probe fields contain a hop count, a destination Ethernet address,
and a source Ethernet address. When a hop probe is received by a network device,
the hop count field is decremented by one and the hop probe is forwarded. Packet
received with a hop count of one are not forwarded and a hop probe reply is sent
back to the Ethernet source address of the hop probe. The hop probe reply fields
contain a destination Etherned address and a source Ethernet address.