DEFENSIVE SYSTEM, DEVICE AND PROGRAM

摘要

PROBLEM TO BE SOLVED: To prevent the depletion of resources at a server side with respect to a large amount of request packets transmitted through a network to the server. SOLUTION: A defensive device 30 inspects the header information of each of a request packet P1 related with a server 6 and a corresponding reply packet P2, and suppresses the passage of the request packet P1 in a boundary router 10 based on the delay of a reply time until the replay packet P2 is returned from the server 6.