Communication system, control device, communication device, and communication method

The present invention increases the flexibility of the control policy and an increase in availability of a control device in a centralized control communication system. The communication system includes: a communication device that processed packets in accordance with control information set from the outside; and a control device that controls the communication device by means of setting control information to the communication device. Furthermore, a first control unit that sets control information in accordance with first rules and a second control unit that sets control information in accordance with second rules are disposed as the control device of the communication system, and the first and second control units control the communication device independently from each other.