ABSTRACT In May 2003, the University of Wisconsin - Madison found that it was the recipient of a continuous large scale flood of inbound Internet traffic destined for one of the campus' public Network Time Protocol (NTP) servers. The flood traffic rate was hundreds-of-thousands of packets-per-second, and hundreds of megabits-per-second. Subsequently, we have determined the sources of this flooding to be literally hundreds of thousands of real Internet hosts throughout the world. However, rather than having originated as a malicious distributed denial-of-service (DDoS) attack, the root cause is actually a serious flaw in the design of hundreds of thousands of one vendor's low-cost Internet products targeted for residential use. The unexpected behavior of these products presents a significant operational problem for UW-Madison for years to come. This document includes the initial public disclosure of details of these products' serious design flaw.…