A Survey on Various DDoS Attacks on Websites

Distributed Denial of Service (DDoS) attacks constitutes one of the most important threats and among the hardest security problems in today's Internet of particular concern are Distributed Denial of Service (DDoS) attacks, whose collision can be proportionally severe. A distributed denial of service (DDoS) attack is designed to overpower victims with traffic and put off their network resources from working correctly for their legitimate clients. Recently, there have been an increasing numbers of DDoS attacks against online services and Web applications.  The most common form of DDoS attacks is a packet-flooding attack, in which a large number of apparently legitimate TCP, User Datagram Protocol (UDP) or Internet Control Message Protocol (ICMP) packets are directed to a specific destination. With small or no prior warning, a DDoS attack can easily fatigue the computing and communication resources of its victim within a short period of time. Because of the seriousness of the problem many defense mechanisms have been proposed to conflict these attacks. This paper presents a survey of various DDoS attacks enforced on web applications as well as online services. Moreover, the paper also provides an outline of various defense mechanisms proposed earlier to counter the DDoS attacks. This paper also presents some fundamental ideas to design and develop a system that better handles the DDoS attacks.