Resarch On Defence Of DDoS Attack In P2P Network

Along with the vigorous development of Internet society becomes colorful, and people become greatly dependent on the network. Meanwhile, the network security faces unprecedented challenge. The threats of Internet mainly include the hacker's invasion and computer virus. Distributed Denial of Service (DDoS) is one of the attacks which is popular and causes large economic loss in recent years. DDoS is a distributed and large scale attack based on DoS (Denial of Service). Attacker transmits massive garbage package which can cause the CPU resource and network bandwidth of target exhausted. The establishment of effective defense mechanism is an important thing for protecting the network security.Peer to Peer (P2P) network technology develops rapidly in recent years. P2P network including Tapestry, Pastry, Chord, CAN has the characteristic of easy to extension and locating the resource in limited hops. P2P has become the hot research topic. But the P2P network architecture is loose, the node can join and withdraw dynamicly. The system has high uncertainty and randomness. The node is unable to confirm the status and credible degree of opposite. And then the DDoS attack is easy to happen. The security problem is important to the further development and application.In this article the DDoS attack principle and several defensive methods are analyzed, and a defensive system based on the defense of target-end DDoS attack is proposed. The system is established on the target-end router. The system can realize the examination adaptively and is a response system. The system divides the current through the target-end router in capacity and connect. The system can suppress the DDoS attack current, and then protect the legitimate current capacity. Finally an experiment of the system's practical application is carried on. The defensive system is proved that can protect the legitimate current, suppress the attack current effectively, and defense the DDoS.