A gateway device disposed at front stage before a server has a dispersion rule of data dispersed on server side and analyzes communication data to specify a server to be accessed finally, so that identification information of the specified server is added to packet option of IP layer to thereby omit higher-rank routing processing than IP layer of gateway devices on the way. Consequently, transfer processing of a gateway device at back stage can be performed at high speed and access passing through a network route intended by manager is possible.