Disruption of service caused by distributed denial of services (DDoS) attacks is an increasing problem in the Internet world. At the present time, to attack the victim's system, the attacker uses sophisticated automated attacking tools for DDoS attack, but earlier it was performed either by manually or by semi automated attacking tools. These attack tools are used to attack various Internet sites. In this paper, we present a literature on classification of available mechanisms for DDoS defense. These defense mechanisms are used to prevent, detect, response and tolerate the DDoS attacks. It is well known that it is very difficult to stop the DDoS attack; therefore, it would be better to maximize the fault tolerance and quality of services under variety of intrusions and attacks. In our analysis, we will discuss the merits and demerits of each mechanism over others. In addition, this paper provides better understanding of the DDoS attack problem and enables a security administrator to cope up against the DDoS threat.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.