Chapter 8. Designing the DNS Namespace

Active Directory is only as reliable and efficient as the domain name system (DNS) service. Today DNS is the foundation for name resolution for the Internet and many corporate resources. Web browsers use DNS to translate Transmission Control Protocol/Internet Protocol (TCP/IP) fully qualified domain names to IP addresses. Mail systems use DNS to resolve mail address domains to specific host names and IP addresses. All over the world, Internet and enterprise applications are dependent on correctly-configured DNS entries for their applications to work properly—now add Microsoft's Active Directory.

DNS is the name master for the world. As one of the services that helps to maintain peace and order in the Internet, Microsoft has made the decision to resolve names by using DNS. Microsoft's Active Directory is dependent on DNS for name resolution in finding resources.

There are several reasons for using the reliance on DNS for Active Directory. The first and most obvious reason is the need to use a service that has demonstrated scalability. Although Microsoft has used the Windows Internet Naming Service (WINS) not only as a NetBIOS name resolver but also as a hostname resolver for many of today's needs, it can be difficult to administer in large environments. DNS has demonstrated its scalability with its widespread use on the Internet as well as in corporate America.

A second reason for using DNS is that it has the capability to integrate with other existing namespaces, namely existing DNS environments. Rather than building a new and improved naming service, Microsoft has embraced the Internet standard and is working to expand its functionality through the standards bodies. Embracing the preexisting DNS infrastructure leverages the current investment of organizations. This provides total cost of ownership (TCO) benefits.

Finally, DNS has a ready place in the computer community. Although DNS might seem outdated in its early forms, you likely already have a trained staff that knows how to create, modify, and administer DNS.