Cisco® Secure Internet Security Solutions

Denial of Service (DoS) Attacks

A DoS attack is designed to overwhelm the victim's network to the point that the victim cannot use the network for legitimate business purposes. A Distributed DoS (DDoS) is simply a DoS that is launched simultaneously from more than one source. Sometimes these attacks are used in an attempt to confuse the equipment to a point where unauthorized access is able to penetrate inside the network. At other times, the attacks are launched merely because the perpetrator wishes to bring down the victim's network connections. In either case, there are some common methods used in DoS attacks that are explored in this chapter, in addition to ways to avoid becoming a victim of these attacks.

SYN Flood Attacks

To understand ...