Distributed Denial Of Service Ddos Attacks Core Technology Research

Though attack in internet is so much and power is so strong, distributed denial of service (DDoS) attack is still number one for threat of internet security, especially along with more and more method of DDoS developed. Certainly, defense for DDoS is studied by step and step and more skills are put forward, for instance, Random Drop arithmetic and SYN Cookie arithmetic are set in firewall and IDS.The new software named "D-Gun" for DDoS is carried out, which completed in Windows 2000 and RetHat Linux. Three characteristics of D-Gun are lied out. First, it can complete all steps of attack automatically; Secondly, it support a lot of method of DDoS, especially support echo attack method and pulsant attack method . Thirdly, it can round firewall in a certain extent. In the process, the attack on router is attempted . In addition, hide port is open for making use of the agent again.In a word, D-Gun is a tool for information war. on the other hand , it results in a litter idea of defense DDoS.In this paper, technology of DDoS and design of D-Gun are introduced. Totally it is divided into six parts, the first of part is introduction . The second part is interrelated technology about D-Gun, including DDoS principium, ports-scan, buffer overflow attack , backdoor and raw socket. The third part is design of D-Gun as a whole, which is thinking in D-Gun. The four- part is module design and implementation in detail , the flows of every module are made out .The fifth part is test and the last part is summary.