Abstract: A data switch is proposed which can be operated such that it generates a MA table of MAC addresses of devices associated with some of its ports, but not the MAC addresses associated with one of the ports. Packets received by the switch, other than from the port, are assumed to be destined for the port and are transmitted via the port. If the port is connected to a network, and all the other ports are connected to a relatively small number of devices, such as one device per port, then the memory requirement to store the MA table is dramatically reduced.

Abstract: A data switch (4) is proposed which can be operated such that it generates a MA table of MAC addresses of devices associated with some of its ports (9, 13, 15, 17, 19), but not the MAC addresses associated with one of the ports (11). Packets received by the switch, other than from the port (11), are assumed to be destined for the port (11) and are transmitted via the port (11). If the port (11) is connected to a network, and all the other ports are connected to a relatively small number of devices, such as one device per port, then the memory requirement to store the MA table is dramatically reduced.

Abstract: An Ethernet data switch maintains one or more queues for each of its ports in a shared memory. The memory is divided into data packets. When a data packet is received, the switch checks whether it can be stored efficiently in the packet buffers, and if the packet cannot be stored efficiently then a portion of the packet is stored in a separate memory and the remaining portion of the packet is stored in the packet buffers.