Abstract: There is provided a modified Ethernet switch for directing data packets to and from a plurality of Ethernet ports. The switch is arranged to forward each data packet outgoing to one of the ports to the correct port as determined by an address lookup table. The switch is operable in two modes. In the first mode, the switch is arranged to forward each data packet incoming from one of the ports to its correct destination port as determined by the address lookup table. In the second mode, the switch is arranged to forward each data packet incoming from one of the ports to a processor. The address lookup table is maintained by the switch. The switch comprises a control block for switching the switch between the first mode and the second mode.