Denial of Service

Denial-of-service attacks are designed to shut down or render inoperable a system or network. The goal of the denial-of-service attack is not to gain access or information but to make a network or system unavailable for use by other users. It is called a denial-of-service attack, because the end result is to deny legitimate users access to network services. Such attacks are often used to exact revenge or to punish some individual or entity for some perceived slight or injustice. Unlike real hacking, denial-of-service attacks do not require a great deal of experience, skill, or intelligence to succeed. As a result, they are usually launched by nerdy, young programmers who fancy themselves to be master hackers.

There are many different types of denial-of-service attacks. The following sections present four examples: ping of death, "synchronize sequence number" (SYN) flooding, spamming, and smurfing. These are examples only and are not necessarily the most frequently used forms of denial-of-service attacks.