Active Directory Cookbook

2.3. Creating a Domain

Problem

You want to create a new domain that may be part of an existing domain tree or the root of a new domain tree.

Solution

Using a graphical user interface

Run dcpromo from a command line or Start → Run.

On a Windows 2000 domain controller, select “Domain controller for a new domain” and then you can select one of the following:

• Create a new domain tree → Place this new domain tree in an existing forest

• Create a new child domain in an existing domain tree

On a Windows Server 2003 domain controller, select “Domain controller for a new domain” and then you can select one of the following:

• Domain in a new forest

• Child domain in an existing domain tree

• Domain tree in an existing forest

Using a command-line interface

dcpromo can also be run in unattended mode. See Recipe 3.4 for more details.

Discussion

The two options dcpromo offers to create a new domain are adding the domain to an existing domain tree or starting a new domain tree. If you want to create a new domain that is a subdomain (contained within the same namespace) of a parent domain, you are creating a domain in an existing domain tree. If you are creating the first domain in a forest or a domain outside the namespace of the forest root, you are creating a domain in a new domain tree.

Each domain increases the support costs of Active Directory due to the need for maintaining additional domain controllers and time spent configuring and maintaining the domain. When designing an Active Directory forest, your goal ...