Even though few companies in the United States have switched to IPv6, other countries have been faster to adopt it. The leaders are Japan, China, South Korea, and Australia. To make things easier, Microsoft developed IPv6 support many years ago, and starting with Windows Vista, it was enabled by default.
On older operating systems, IPv6 was available as an extra add-on. In Windows XP, for example, all you have to do to add it is open a command prompt on the client and run the command netshint ipv6 install
. On Windows 2000 computers, you can add IPv6 by installing an add-on pack from http://www.microsoft.com/enus/download/details.aspx?id=21676.
On other operating systems such as MacOS, Linux, and others, IPv6 is supported as well. Macintosh computers have had IPv6 support since Mac OS v10.3 (also known as Panther, released in late 2003). Linux kernels have supported IPv6 since the year 2000, with some code implemented in version 2.1.8 of the kernel, and any distribution using version 2.6 or later should support it fully.
To be clear, the preceding paragraph doesn't mean that these systems can become URA clients; we are only talking about the ability of the operating system to use IPv6, which impacts how it will integrate into the network.