Security

Denial of Service

Denial-of-service attacks have become one of the most common forms of attack on the Internet today because many can be started remotely.

There are two types:

• The first occurs when a system is so utterly consumed that it cannot spare any further resources for other users.
• The second occurs when a system is made to crash and hence it cannot service other users.

An example of the first type of denial of service is a program that swamps all the printers in an organization with massive high-priority print jobs. This will prevent all other users from printing any documents and, in the case of a company that relies on printing to perform its core business function, could result in a loss of earnings.

An example of the second type of denial of service is a program that sends a large block of data to a remote program, knowing that the server will fail when it attempts to process the data. This is often referred to as a “buffer overflow” attack.

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