| 摘要 |
<P>PROBLEM TO BE SOLVED: To easily detect and invalidate a connection of a terminal which is not permitted. <P>SOLUTION: A network control unit 40 is interposed between an authentication server 20 and an authentication switch 30 for authenticating a terminal device 10, and configured to intercept communication contents, based upon an authentication protocol, communicated between the authentication server 20 and terminal device 10. The network control unit 40 stores an identification address of the terminal device 10 approved by the authentication server 20 from the intercepted communication contents. Therefore, when an arbitrary terminal device tries to connect with the LAN and transmits an identification address, the identification address is compared with an identification address of an approved terminal device to check whether they are different, thereby easily detecting whether the connection is illegal. <P>COPYRIGHT: (C)2009,JPO&INPIT |
