Patent ID: 7154890

Claim:
A packet transfer device comprising: a plurality of input/output ports; a header information extracting circuit for extracting header information belonging to a third layer and a higher layer of a network protocol from a packet inputted from the respective input/output ports; a table storing header information and control information corresponding to the header information in association with each other; a control information acquiring circuit for acquiring the control information corresponding to the header information extracted by said header information extracting circuit from the table; a processing circuit for processing packets based on the control information acquired by said control information acquiring circuit; and a process determining circuit for determining a process to be actually performed by said processing circuit if the control information is acquired from a plurality of tables with respect to one packet by said control information acquiring circuit; where the control information represents either one of said input/output ports from which the packet is output, and said process determining circuit outputs the packet from the input/output port represented by the control information acquired from the table containing header information belonging to the higher layer.