Patent ID: 7853642

Claim:
A network system, comprising: at least one network unit having a variable Internet protocol (IP) address and unique identification information; a dynamic host configuration protocol (DHCP) server responsive to a request from said at least one network unit for assigning said variable IP address to said at least one network unit for a predetermined period of time; and an agent server comprising: a communication unit for receiving said unique identification information and said variable IP address from said at least one network unit, for transferring said unique identification information and said variable IP address, and for receiving from a user unique identification information of a network unit selected by the user; a database connected to said communication unit for receiving and storing said variable IP address and said unique identification information transferred from said communication unit; and a control unit connected to said communication unit and to said database for receiving from the user via said communication unit said unique identification information of said network unit selected by the user, for searching said database for said variable IP address of said at least one network unit on the basis of the unique identification information received from the user, and for enabling the user to gain access to said selected network unit in accordance with results of the searching of said database, wherein said unique identification information received from the user comprises at least one of an Ethernet address of said at least one network unit and a search keyword for said variable IP address of said at least one network unit, wherein the Ethernet address comprises an address which corresponds to and is not the same as said unique identification information received from said at least one network unit, and wherein the search keyword comprises a keyword which corresponds to and is not the same as said unique identification information received from said at least one network unit.