| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent unauthorized access by the use of a forged IP address in an image processor having the function of printing an image in accordance with print data received via a network communication. <P>SOLUTION: A host PC_1 103 forges a sender IP address and transmits a packet to an image forming apparatus 101. The forged sender IP address is an IP address of a host PC_2 104. The image forming apparatus 101 receives the packet and transmits a packet for confirming presence or absence of the access to a device (the host PC_2 104) having the sender IP address which is set in the packet. Even when the host PC_2 104 receives an access confirmation packet, it does not respond to the image forming apparatus 101. Since the image forming apparatus 101 is not able to receive a response packet, it does not perform the communication. <P>COPYRIGHT: (C)2009,JPO&INPIT |
