From approximately on April 6th - April 8th, the University of Minnesota experienced intermittent and spotty network latency on the East Bank north of Washington Avenue.
OIT engineers have determined that the problems were caused by a multicast-related hardware malfunction. The symptoms were very slow network connectivity, and in most cases, it would horribly slow down the Windows PC by tying up system resources.
A printer on the East bank was sending out unsolicited service announcements via the Windows Plug and Play mechanism at a very high rate, effectively a flood. The owners of this printer have several of this variety and have engaged their vendor’s technical support to ultimately fix this hardware problem.
Because Plug and Play is a Windows facility, only Windows boxes were affected by this problem. Even though Windows boxes were vulnerable, people who had suitable software Firewalls (such as the Symantec Firewall) were unaffected. It appears at this time that the Windows Firewall that is native to XP Service Pack 2 was unable to stop it.
OIT is working on ways to mitigate this kind of problem in the future. This problem would have been limited by limiting how far Plug and Play were allowed to propagate.
If you have additional questions about this outage, please call (612) 301-4357 (1-HELP on campus).