This topic explains the support for Internet Protocol Version 6 (IPv6) addressing in Microsoft Exchange Server 2007 Service Pack 1 (SP1).
What is IPv6? IPv6 is a new version of the Internet Protocol. The current version of the Internet Protocol is known as Internet Protocol Version 4 (IPv4). IPv6 is intended to correct many of the shortcomings of IPv4, such as a decreasing pool of available addresses, lack of extensibility, and lack of autoconfiguration. For example, IPv6 addresses are 128-bits long. In contrast, IPv4 addresses are 32-bits long. There are enough IPv6 addresses for every person on earth to have trillions and trillions of IPv6 addresses assigned to them.
Because IPv4 and IPv6 are completely different protocols, an IPv4 network can't communicate directly with an IPv6 network, and vice versa. Network administrators deploy devices, such as routers, that can route information between IPv4 networks and IPv6.
Although IPv6 was officially defined in RFC 2460 in 1996, native IPv6 environments are rare. Most administrators deploy a dual environment where both IPv4 and IPv6 are configured and supported on the network.
For more information about IPv6, see IPv6.
Microsoft, Exchange Server 2007, Service Pack, Exchange 2007 SP1, IPv6, Guide, Knowledgebase, Article