With the explosion of the World Wide Web and email the 32-bit addresses Internet Protocol version 4 used would run out in the not-so-distant future. In 1994, the Internet Engineering Task Force (IETF) established a working group to define the successor to IPv4, IPv6. In March 2008 the US government issued a memorandum requiring that by June 2008 "all agencies" infrastructure must be using IPv6. This article provides the rationale for the US government's edict, along with the technical features that distinguish IPv6 from its predecessor, IPv4.