Ethernet Topology Detection from a Single Host without Assistance of Network Nodes or Other Hosts

Topology information has become more important for management of LANs due to the increasing number of hosts attached to a LAN. We describe three Ethernet topology discovery techniques that can be used even in LANs with Ethernet switches that have no management functionality. Our “Shared Switch Detection (SSD)” technique detects the Ethernet tree topology by testing whether two paths in the network share a switch. SSD uses only general MAC address learning. By borrowing MAC addresses from hosts, SSD can be run from a single host. The second technique determines whether two paths between two pairs of hosts contain a switch. The third reduces the number of shared switch detections. Simulation showed that these techniques can be used to detect the Ethernet topology with a reasonable search cost. Examination on a real-world testbed showed that they could detect an Ethernet topology consisting of six hosts and two switches within one second. key words: Ethernet, topology detection, network probing