The attacks caused users either to lose connection altogether to the LAN and, consequently, to the Internet, or to experience delays when connecting to the network. Distributed denial of service attacks emanate from multiple directions and are more difficult to detect and defend against than simple denial of service attacks, says John Hanks, UCIS manager of network engineering. Like time bombs, the tools may then be set to unleash an attack at any given time. Because the master computer is not communicating with the machines at the time of the attack, identifying the machine orchestrating the attacks can be quite difficult. It could be anywhere in the world.
Hanks believes one of the master computers involved in the recent attacks is located in Brazil.
Because Hanks was working late on the evening of July 26, he noticed the first attack. The network control center contains several computers that monitor data traffic flow on the university s networks. This can be a telltale sign of a denial of service attack. What s happening, he explains, is that the attacking computers suddenly unleash a volley of garbage, which overloads the system, using up the network s resources and making it impossible for the network to do its regular thing. On the first night, the attack ended before Hanks was able to determine its source, but the next evening he was ready.