In a bridge for interconnecting local area networks, the decision on whether or not to forward a frame is based on the frame's destination address. This is made possible in a practical bridge by a hardware-based prefilter which causes an abbreviated representation of the destination address of each frame to be generated, and uses the representation to address a global address table or "GAT" memory. Each cell of the GAT memory may correspond to more than one destination address. If any destination address, corresponding to the cell addressed by the prefilter, is active on a remote local area network, the prefilter allows the frame to be forwarded for further filtering by a software-controlled processor. Otherwise, the frame is discarded.