A system and method for mapping original Media Access Control (MAC) addresses to unique locally administered virtual MAC addresses in an Ethernet network. A first field of the address may include a domain for the address, and a second field may indicate that the address is a locally administered MAC address. A third field of the address may include an index indicating a number of virtual MAC addresses for each user. Fourth and fifth fields of the address may include a Network Element ID (NE ID) for uniquely identifying a given access node in a given domain, and a Port ID for uniquely identifying an end-user port at the given access node. The system may be implemented in an access node or in a network emulator, which generates unique locally administered MAC addresses for all of the nodes in the Ethernet network for performing emulations of the network.