METHOD AND APPARATUS FOR RESPONDING DDoS OFFENSIVE

Disclosed are a method and an apparatus for preventing a DDoS attack. The method for preventing the DDoS attack comprises the steps of: extracting a path value of a router, a source IP address, and the period of the survival from an input packet; comparing the extracted path value of the router with the preset path value of the router and determining whether or not the spoofing of the input packet exists; calculating a hop number of the input packet if the input packet is the spoofed packet; and blocking a non-spoofed input packet if the calculated hop number does not meet a preset criteria. Therefore the DDoS attack can be effectively prevented.