Patent ID: 8832272

Claim:
A network system comprising: a plurality of servers connected to a network; a plurality of relay processing devices connected to said network; a plurality of switches arranged in said network; and a controller configured to control said plurality of switches, wherein: each of said plurality of servers is assigned to at least one of said plurality of relay processing devices; each of said plurality of relay processing devices performs predetermined processing with respect to a packet to a server assigned to said each relay processing device; and each of said plurality of switches has a flow table indicating a correspondence relationship between an input source and a forwarding destination of a packet with respect to each flow and forwards a packet received from said input source to said forwarding destination by reference to said flow table, wherein said controller comprises: a memory unit; a route design unit configured to design, in response to a request from a request source switch among said plurality of switches, a route of a flow from said request source switch to a destination address; and a switch setup unit configured to instruct each switch on said designed route to set said flow table such that a packet of the flow is forwarded along said designed route, wherein information stored in said memory unit comprises: network configuration information which indicates a connection state between said plurality of servers, said plurality of relay processing devices and said plurality of switches; and assignment information which indicates an assignment relationship between said plurality of servers and said plurality of relay processing devices, wherein said route design unit refers to said assignment information to select, as a target, any one relay processing device assigned to a server specified by said destination address, and said route design unit refers to said network configuration information to design said route so as to include said target.