Analysis Of Distributed Denial Of Service(DDoS) And Implementation Of Its Tool Set

Since the 1980s, Internet has got rapidly development. The networkscale is expanding at the same time. With the prosperity of the Internet,network security problems occur frequently, various ways of attack appearceaselessly, as a consequence, the secrecy, integrality and availability ofcomputer network are under severe challenge. At present, the threats toInternet security mainly come from three aspects: Hacker invading attack,Computer Virus and Denial of Service attack.Initially, DoS was not a way of network attack, but appeared as a testtool of network, which could test the maximum bandwidth, the run ability ofnetwork equipment and the maximum load ability of servers etc. Later DoSwas misused as means of network attack, the main problem attackers facedwas network bandwidth. Distributed Denial of Service (DDoS) Attack is anewly developed attack type of galactic destroying power, which is theextension of Denial of service (DoS) Attack. Due to its distributioncharacteristic, DDoS attacks have more resources to attack than traditionalways of DoS attacks and have more destroying power. So, it is very difficultto prevent them. DDoS attacks bring much great threat to Internet security.And researching on them becomes a hotspot in network security fields.We shall begin the article with TCP/IP protocol relevant to DoS/DDoSand invading techniques, to make clear relevant principles of DDoS attacks,in order to acquire some basic knowledge for further studies on principles ofDoS/DDoS attacks. Then the classification of DoS attacks methods andfrondose fashions are analyzed and detailed analysis on DDoS attacks tools.With the development of automated DoS attack tools; DoS attacks make agreater threat against network security. At present, the majority researchersare focus on attack detection and respond mechanism, yet limited progresshas been made in the details of DoS attacks. We collect large amount ofrelated information, and take a deep research in the methodology of DoSattacks. Two typical DDoS attacks, including Smurf and chargen-echo loop,are simulated in CASL.We can go on further research due to Custom Audit Scripting Language(CASL), a powerful security tool. CASL is a high-level programminglanguage that provides various packet templates and powerful networkprogramming functionality, and can be easily used to write programs thatsimulate low-level attacks or information gathering checks on networks.CASL is similar to C in syntax, and easy to learn and used as shell-scriptlanguages. CASL programs are executed through interpretation and don't...