In a network switch including a user network port connectable to a user network, a plurality of down link ports each connectable to one server unit, a server unit management network port connectable to a server unit management network for managing the server unit, a store-and-forward switching unit connected to the user network port, the down link ports and the server unit management network port, and a control unit connected to the store-and-forward switching unit, when a packet that has arrived at one of the down link ports is a dynamic host configuration protocol (DHCP) packet including a network boot option, the control unit operates the store-and-forward switching unit to transmit the packet to the server unit management network port.