A switch includes a plurality of ports including at least one bus port associated with ports connected to other switches in a network and a memory to store a hash table including MAC addresses and VLAN ids of ports in the network. For each one of the VLAN ids, one of the MAC addresses identifies one of the other switches having ports belonging to the one of the VLAN ids without identifying the ports of the one of the other switches that belongs to the one of the VLAN ids.