Patent ID: 7292581

Claim:
A method of preventing Layer 2 (L2) loops in a Metropolitan Area Network (MAN) having a plurality of intermediate network devices, and providing a plurality of Virtual Ethernet Connections (VECs), each representing a virtual shared medium, the method comprising the steps of: organizing the plurality of intermediate network devices into two or more administrative groups, each containing one or more intermediate network devices; using an Interconnect Fabric to couple the two or more administrative groups by providing redundant links between each administrative group and the Interconnect Fabric; defining one or more logical Trunks within the Interconnect Fabric, each logical Trunk representing a shared medium connecting two or more administrative groups; assigning each VEC to no more than one logical Trunk; and for each VEC provided by an administrative group, blocking all but one of the redundant links to the Interconnect Fabric.