Ethernet Linktrace (ETH-LT)


The IEEE 802.1ab Ethernet linktrace (ETH-LT) function is primarily responsible for restarting the adjacency relationship and helping to locate faults. Otherwise known as a MAC trace route, ETH-LT are multicast messages that a source endpoint sends to track the hop-by-hop path to a destination device. Within a 5 second period, each intermediate device the received the linktrace datagram returns a trace route reply to the originating equipment and regenerates the ETH-LT message on to its destination. The ETH-LT PDU includes fields for a Transaction ID, Time-to-Live (TTL), origin and target MAC addresses.