Windows Server 2008 Active Directory Domain Services

4. Step 1: Determine the Number of Forests

Every Active Directory implementation will have at least one forest. The first step in Active Directory design is to determine whether one or multiple forests are required to meet the organization’s objectives. If multiple forests are required, then the total number of forests needs to be determined.

Getting this decision correct in the beginning is important. As planning progresses, the assumptions that are driven by this design decision will make changing the configuration more difficult. It is considerably more difficult to collapse forests once they have been established than it is to add additional forests later.