DEVICE FOR DEFENDING DNS CACHE POISONING ATTACK

摘要

PROBLEM TO BE SOLVED: To simply defend a DNS (domain name system) cache poisoning attack.;SOLUTION: An attack defense device 14 is arranged between a DNS server 11 and a DNS cache server 12. An inquiry receiving part receives an inquiry packet transmitted from the DNS cache server 12 addressed to the DNS cache server 12. The inquiry transmitting part transfers the inquiry packet to the DNS server 11. A response receiving part receives a response packet corresponding to the inquiry packet arriving at the attack defense device 14 during a fixed period from an IP address inquiry time by the inquiry packet. A response determining part determines that a response packet is a normal response packet when finding a combination of the inquiry packet and the response packet corresponding to the inquiry packet received during the fixed period is set to 1 to 1.;COPYRIGHT: (C)2011,JPO&INPIT