This invention provides a technique for safely and readily managing a network device. To achieve this object, an authentication server (105) performs an authentication process by using a set of a login ID and password transmitted from a manager server apparatus (103), and transmits the authentication result to a multi-functional peripheral (102). The authentication server (105) also specifies a VLAN name corresponding to this set, and transmits the VLAN name to a DHCP server (106). The DHCP server (106) determines connection setting information corresponding to the VLAN name, and transmits the determined connection setting information to the multi-functional peripheral (102). The multi-functional peripheral (102) connects to VLAN 2 by using the obtained connection setting information.