a device search module, configured to perform a search and read process by using simple network management protocol (SNMP) to discover and retrieve an image-forming apparatus and image-forming-apparatus information in a local area network, wherein the search and read process includes obtaining a local gateway address in the local area network according to a specified time interval;

an internal storage apparatus, configured to store the image-forming-apparatus information after search;

a display interface, configured to display the image-forming-apparatus information stored in the internal storage apparatus for a user to select image-forming-apparatus information to-be-monitored from the image-forming-apparatus information and to monitor an image-forming apparatus corresponding to the image-forming-apparatus information to-be-monitored; and

a determination unit, configured to determine whether the user selected image-forming-apparatus information matches at least a part of the image-forming-apparatus information of any monitored image-forming apparatus; and if a match is determined, configured to update the image-forming-apparatus information of the corresponding monitored image-forming apparatus, such that an image-forming-apparatus information change of the corresponding monitored image-forming apparatus is updated automatically,

wherein for the search and read process, the device search module is configured to calculate an IP address in the local area network according to the local gateway address.