Patent ID: 7359389

Claim:
A packet switch for interfacing between a WAN and a LAN accommodating a terminal, said packet switch comprising: a plurality of LAN interface units for interfacing with said LAN; an address table for storing a relation between an address of the terminal and an input port receiving a packet transmitted from the terminal; an address learning unit for storing in said address table the relation between the source address of the received packet and the input port receiving the received packet; and an SW unit for effecting control to receive a packet transmitted from a terminal accommodated in said LAN and received by a first LAN interface unit of said plurality of LAN interface units, and transmit the received packet to a corresponding output port according to a relation between a destination address of the received packet and the input port when the destination address is stored in said address table, and effecting control to transmit the received packet to the LAN through all of the LAN interface units different from the first LAN interface unit when the destination address of the received packet is not stored in said address table, and then transmit the received packet to the WAN when a packet having a source address identical with the destination address of the received packet has not been received from the LAN in a certain time after transmitting the received packet to the LAN.