IPv6 has been “the next generation of TCP/IP protocols” for so long that you can be forgiven for thinking that it will never be useful. However, with Windows 7, Microsoft has finally given network administrators a reason to consider using IPv6.

First, some background. The reason why IPv6, a.k.a. RFC 2460, was created back in 1998 was to give network administrators more network addresses than they could possibly use. It was widely predicted that the Internet would soon run out of IPv4 32-bit addresses. IPv6, with its 128-bit addresses and the resulting astronautical address range seemed the perfect answer.

It wasn’t. Both the Internet and the vast majority of American and European business users elected to stay with the legacy IPv4 network. To get around the much-predicted Internet IPv4 address famine, people turned to network address translation (NAT) and Dynamic Host Configuration Protocol (DHCP). With this combination, thousands of corporate PCs can have their own internal IPv4 addresses while using up only a single IP address, as far as the Internet is concerned.

While Internet administrators were working out this (and other) ways to deal with the shortage of IPv4 addresses, Microsoft was tinkering with IPv6 in Windows. The protocol was available as a little-used test protocol in Windows 2000. By the time Windows XP and Windows 2003 rolled out, IPv6 was built into the operating systems.

More >