When points are connected by a L2VPN, it is necessary to unify the address system (network). When the user sets the address manually, address duplication may occur or the network may not be unified due to a setting mistake. In addition, when points are connected by a L2VPN, the VPN internet connection is redundant, and therefore must be prevented. The delegate CE router from among the CE routers that make up the VPN determines the address that is distributed by the other CE routers on the LAN. The determined address is included in the control message for establishing the VPN and the address is then distributed to the other CE routers. Also, the control message for establishing the VPN includes the interface MAC address that is used by the CE routers on the LAN. Each CE router controls the channel according to the MAC address of the next-hop router.