Abstract
As the dependency on web technology increases every day, there is on the other side an increase in destructive attempts to disrupt an essential web technology, which yields an improper service. Denial of Service (DoS) attack and its large counterpart Distributed Denial of Service (DDoS) and Flash Crowd attacks are among the most dangerous internet attacks, which overwhelm the web server, thereby slow it down, and eventually take it down completely. This review paper evaluates and describes the effectiveness of different existing Frameworks and Schemes for Detecting and Preventing High Rate DoS/DDoS and Flash Crowd Attacks. Firstly, the review paper describes them according to the similar category, and then it compares them based on the predefined metrics. Finally, advantages and disadvantages for each category are described.