Distributed Denial-of-Service Attack

Denial-of-service attacks aim to disrupt a given service (e.g., a web server), thus hurting the business that offers the service. There are many ways [Page 251]to deny a service. The most common form of attacks send high-volume traffic to the service, which competes with legitimate clients’ traffic for a limited resource at the server. The targeted resource could be bandwidth, server memory, server CPU, or server sockets. Other attacks target related services such as the Domain Name System (DNS) or routing infrastructure, which clients need to reach many other services. Still other attacks exploit a vulnerability to make the service crash.

Distributed denial-of-service (DDoS) attacks send attack traffic from multiple locations. Usually an attacker recruits a botnet and uses it to generate DDoS attacks. Most denial-of-service ...