The agencies involved include the departments of Agriculture, Commerce, Defense, Education, Energy, Health and Human Services, Homeland Security, Housing and Urban Development, the Interior, Justice, Labor, State, Transportation, Treasury and Veterans Affairs. The GAO also studied IPv6 efforts by the Environmental Protection Agency, the General Services Administration, NASA, the National Science Foundation, the Nuclear Regulatory Commission, the Office of Personnel Management, the Small Business Administration, the Social Security Administration and the U.S. Agency for International Development.

To help the various agencies in their efforts, a series of IPv6 Working Group subcommittees was established in May to address issues related to the transition, including security, testing and standards, according to the GAO.

To smooth the transition to IPv6, the GAO recommended that the head of the OMB direct federal agencies to work through the CIO Council Architecture and Infrastructure Committee and the IPv6 Working Group.

GAO spokesman David Powner said Tuesday that several of the agencies, including the Social Security Administration and the Department of Education, fared better in the analysis by having completed more of the work than other agencies. "I think it is safe to say, though, [that] all agencies have a fair amount of work ahead," he said.

IPv6 is in various stages of testing and use around the world. IPv6 has more than 10 years of development behind it and is already deployed in some production networks.