A network system comprising: a hub base that includes a first network device with a hub function, the first network device being connected to an information communication network; and a spoke base (4a, 4c) that includes a second network device (41a, 41c) without the hub function, the second network device being connected to the information communication network, wherein communication between a computer provided in the spoke base (4a, 4c) and an external device connected with the computer via Internet is performed such that intra-network loopback communication is performed between the first network device and the second network device (41a, 41c) in the information communication network without an internet service provider, and communication is performed between the first network device and the external device via the internet service provider, wherein, in response to an issuance request to the information communication network to issue address information from the second network device (41a, 41c), the internet service provider issues address information in a case where the spoke base (4a, 4c) has an IPoE-type provider subscription and the information communication network issues the address information in a case where the spoke base (4a, 4c) does not have the IPoE-type provider subscription, the second network device (41a, 41c) performs VPN connection with the first network device by an Internet VPN method in a case where the address information has been issued by the internet service provider, and the second network device (41a, 41c) performs the VPN connection with the first network device by intra-network loopback in a case where the address information has been issued by the information communication network. a hub base that includes a first network device with a hub function, the first network device being connected to an information communication network; and a spoke base (4a, 4c) that includes a second network device (41a, 41c) without the hub function, the second network device being connected to the information communication network, wherein communication between a computer provided in the spoke base (4a, 4c) and an external device connected with the computer via Internet is performed such that intra-network loopback communication is performed between the first network device and the second network device (41a, 41c) in the information communication network without an internet service provider, and communication is performed between the first network device and the external device via the internet service provider, wherein, in response to an issuance request to the information communication network to issue address information from the second network device (41a, 41c), the internet service provider issues address information in a case where the spoke base (4a, 4c) has an IPoE-type provider subscription and the information communication network issues the address information in a case where the spoke base (4a, 4c) does not have the IPoE-type provider subscription, the second network device (41a, 41c) performs VPN connection with the first network device by an Internet VPN method in a case where the address information has been issued by the internet service provider, and the second network device (41a, 41c) performs the VPN connection with the first network device by intra-network loopback in a case where the address information has been issued by the information communication network.