Denial-of-Service Attacks: A Special Case

Denial-of-service (DoS), or flooding attacks, have been used for many years by hackers. They
are launched by capturing a large number of terminals and using them to transmit meaningless
messages that flood the public network affected beyond its carrying capacity.
DoS attacks are different from viruses and worms. They do not introduce malicious
code into network elements or management software, and they are transitory in their effects.
And yet they can shut down a network effectively for hours. Recently several vendors have developed software to detect the presence of DoS attacks and to prevent network elements
from continuing to pass the bogus transmissions that characterize such attacks.