DNS on Windows Server 2003, 3rd Edition

Domain Models

Two Active Directory domain models are commonly used. Your choice of domain model is important because it dictates DNS requirements, as we discuss later. One model consists of an empty root domain with geographic or organizational subdomains. We recommend that you do not create organizational-based subdomains if you can help it since they are very likely to change at some point.^[3]

Some of the benefits of the multidomain model include the ability to delegate administration for management of portions of a forest, greater control over how data is replicated within the forest, and decreased exposure to problems that can impact a single domain. For example, if an application went out of control and mistakenly started creating tons of objects in a domain, at some point the hard disk on the domain controllers in that domain would fill up. The domain would then enter an unstable and possibly unusable state. However, the domain controllers in other domains would continue to function without much impact. This example is admittedly contrived, but it shows you the benefits of autonomy in the multidomain model.

The downsides of this model include the increased support costs of setting up additional domain controllers—remember that each domain must have its own set of domain controllers—and additional domain configuration (configuring security, group policy objects, organizational units, etc.). Also, finding data in a multidomain forest is not always easy. Since data can be spread ...