Denial-of-service attacks could come during Y2K weekend.

As the pre-Y2K hype enters its final phase, computer watchdogs have identified twonew techniques for bringing Internet sites down: One of the denial-of-service attacks is nicknamed TFN2K, the other is called the "Mac Flood Attack." Neither of them is directly related to the Year 2000 computer bug itself, but the failures they cause could be misinterpreted as New Year_s glitches. TFN2K is a variant of a previously reported denial-of-service attack known as TFN or Tribe FloodNet . The attacker can make it look like data requests are coming in from multiple sources - which makes it harder to track down the source of the attack.TFN2K adds another twist by intentionally sending data errors "designed to crash or introduce instabilities in systems," the center said. CERT advised system administrators to follow industry guidelines to guard against denial-of-service attacks, and to install filtering software that recognizes when Internet traffic is coming from bogus sources. The second attack strategy targets Apple Macintosh computers running the MacOS 9 operating system with full-time connections to the Internet (under some conditions, systems using MacOS 8.6 also may be vulnerable). John Copeland, a computer engineering professor at the Georgia Institute of Technology, reported that an attacker could send relatively small amounts of fake data in such a way that the Macs would be triggered to send larger transmissions in reply.