Abstract: A shared I/O subsystem having a plurality of ports, where each of the ports includes a plurality of address bits and first and second masks associated therewith. The shared I/O subsystem receives a data packet from a first of the plurality of ports, selects from one or more tables the plurality of address bits and the first and second masks associated with the first port, applies an AND function to the address bits and the first mask associated with the first port, applies an OR function to the result of applying the AND function and the second mask associated with the first port, and selectively transmits the data packet to one or more of the ports in accordance with a result of applying the OR function.