A switch apparatus includes: a plurality of ports; a VLAN setting management unit that sets VLAN information in the plurality of ports and manages the VLAN information set in the plurality of ports; and a VLAN setting unit that, when VLAN information to be added to an output packet specified in control information received from a predetermined control apparatus is not set in an output port for the output packet, instructs the VLAN setting management unit to set VLAN information specified in the control information in a corresponding output port.