In a switching node, high-speed and advanced service protocol processing function is achieved by utilizing an external control server without affecting performance of conventional service protocol processing. Specifically, a forwarding engine has PCI express and an LAN interface. Depending on a type of an input packet, destination of the packet is switched to the PCI express side for conventional network service and to the LAN interface side for extended network service that cooperates with the external control server. A CPU having the PCI express and the LAN interface is provided ahead of the LAN interface. The CPU performs communication of service inquiry with the external control server at high speed via the LAN interface. After response from the control server is obtained, setting of the forwarding engine is performed through the PCI express.