A hub for a segmented virtual local area network with shared media access has at least one internal port for receiving and transmitting digital data messages within the hub and may have at least one external port for receiving and transmitting digital data messages external to the hub. The hub further includes a memory for storing virtual local area network (VLAN) designations for internal and external ports. The hub associates VLAN designations with at least one internal port, stores such VLAN designations in the memory, and associates the stored VLAN designations with messages transmitted from any of the ports to which the VLAN designation has been assigned. Additionally, the hub identifies VLAN designations associated with messages received by or within the hub and means and transmits to any of the internal ports only messages received within the hub and having associated with them a VLAN designation which matches the stored VLAN designation assigned to the port. The hub also has the ability to store media access control (MAC) addresses of internal ports and of end stations connected to internal or external ports and only send a message to a port when the destination address of the message is the MAC address of that port or of an end station known to be reachable through that port.