Outlining Windows Server 2008 R2 IPv6 Support

When the original structure of the Internet was taking shape, an addressing scheme was formulated to scale to a large number of hosts. From this thinking came the original design of the Internet Protocol, which included theoretical support for around 4 billion addresses, or 2³². The thinking at the time was that this would be more than enough addresses for all hosts on the Internet. This original design gave birth to the IP address structure that is common today, known as dotted-decimal format (such as 12.155.166.151). At the time, this address space filled the addressing needs of the Internet. However, it was quickly discovered that the range of addresses was inadequate, and stopgap measures such as Network Address Translation (NAT) were required to make more efficient use of the available addresses.

In addition to an inadequate supply of available addresses, the Internet Protocol version 4 (IPv4), as it is known, did not handle routing, IPSec, and QoS support very efficiently. The need for a replacement to IPv4 was evident.