There is provided a load distribution function that enables an application of a user to be freely allocated to a machine even if an address of a terminal or the application used by the user is duplicated between VPNs for each user. An access detector of a machine allocation device detects a start packet from received communication packets, and determines the type of the start packet and the type of the application used by the terminal. A machine allocation manager determines a machine on which the determined application operates, and operates the machine. A network manager configures a user virtual network on a second virtual network between the determined machine and the machine allocation device.