Patent US 7,577,142

A method of operating a switch for frames in a computer network uses one or more indicia of frame type designation found in the received frame to derive a virtual local area network (derived VLAN) value. Also, an indicia of the receiving port may be used in constructing the derived VLAN value. The switch then uses the derived VLAN value in making forwarding decisions. Broadcast domains in the computer network may then be controlled by forwarding in response to the derived VLAN value.