8. Appendix A. Background

   In May 2003, the University of Wisconsin discovered that a network
   product vendor named NetGear had manufactured and shipped over
   700,000 routers with firmware containing a hard-coded reference to
   the IP address of one of the University's  NTP servers:
   128.105.39.11, which was also known as "ntp1.cs.wisc.edu", a public
   stratum-2 NTP server.

   Due to that embedded fixed configuration and an unrelated bug in the
   SNTP client, the affected products occasionally exhibit a failure
   mode in which each flawed router produces one query per second
   destined for the IP address 128.105.39.11, and hence produces a large
   scale flood of Internet traffic from hundreds of thousands of source
   addresses, destined for the University's network, resulting in
   significant operational problems.

   These flawed routers are widely deployed throughout the global
   Internet and are likely to remain in use for years to come.  As such,
   the University of Wisconsin, with the cooperation of NetGear, will
   build a new anycast time service that aims to mitigate the damage
   caused by the misbehavior of these flawed routers.

   A technical report regarding the details of this situation is
   available on the world wide web: Flawed Routers Flood University of
   Wisconsin Internet Time Server [11].