NETWORK SYSTEM, AND ROUTE CONTROL METHOD

PROBLEM TO BE SOLVED: To achieve "the Proactive type" in an open flow network, and to resolve problems in performance of hardware (HW).SOLUTION: In an open flow network, each of a plurality of switches performs an operation according to an action defined by an entry, to a reception packet conforming to a rule of the entry registered in its own flow table. A controller uses as a rule an identifier unique to a path calculated depending on a physical topology of a network formed by the plurality of switches to register an entry using an output from a predetermined output port as an action before (in advance) starting communication among the plurality of switches.