Tracing of hardware addresses in layer two bridged networks

In modern IEEE 802 based networks the knowledge of the topology including the originating source of a given hardware address is desired. While in the network layer the command “traceroute” performs an Internet Protocol (IP) based route trace across a network by the interpretation of echo replies and time exceeded messages, a similar method for the data link layer based on hardware addresses is not generally available. To provide this functionality, an organizationally specific protocol extension for the IEEE 802.1AB Link Layer Discovery Protocol (LLDP) is proposed. Based on LLDP, which exchanges messages between two (or more) neighboring network devices, additional Type Length Value (TLV) elements are defined to be exchanged not only between direct neighbors but also on a link layer end-to-end basis. The protocol extension allows the trace of a hardware address through a layer two based network. The requesting device is able to present the path to a certain destination hardware address with any supporting device on the trace path with outgoing and incoming interface.