| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to surely place a limit on communications apparatuses whose communication with an external network is permitted among the communications apparatuses connected to an intranet and to prevent the limitation from being found out. SOLUTION: When a gateway apparatus installed at a border between the intranet and the external network receives an ARP request from a communications apparatus accommodated in the intranet, the gateway apparatus discriminates whether or not a sender of the ARP request is a predetermined communications apparatus on the basis of a MAC address written in the ARP request. When the result of the discrimination is affirmative or number of communications apparatuses, to which an ARP acknowledgement is returned from the gateway apparatus does not reach a prescribed upper limit, even if a result of the discrimination is negative, the gateway apparatus returns the ARP acknowledgement to the sender of the ARP request. COPYRIGHT: (C)2007,JPO&INPIT
|
