Abstract: An overall management device decides network information on an internet GW router and a router. A cloud environment management device performs a first setting on the internet GW router based on the network information decided by the overall management device and cancels, if the first setting has failed, the first setting performed on the internet GW router. A local connection environment management device performs a second setting on the router based on the network information decided by the overall management device and cancels, if the cloud environment management device fails the first setting, the second setting performed on the router.

Abstract: A virtual resource information storing unit stores therein information on physical network device in which each virtual resource is arranged and a physical device information storing unit stores therein the number of remaining definitions of each of the physical network devices. When the device management unit is not able to add to a virtual resource arranged in a physical network device, the device management unit rearranges the virtual resource to another physical network device by using the virtual resource information storing unit and the physical device information storing unit.