A communication apparatus selects, among a plurality of control information, the control information matching a packet received and which is highest in a priority level. The communication apparatus processes a packet received based on the selected control information. The control apparatus includes a control information generation unit that generates a plurality of control information having match conditions overlapping at least partially one with another, a ranking in a priority level different one from another and processing contents different one from another, and a control unit that sets the plurality of control information in the communication apparatus. The communication apparatus performs the processing of modifying the control information, among the plurality of control information, which is highest in a priority level, based on a modifying condition previously set on the control information basis. Communication policies may be changed over by modifying the priority level.