Creating the First Domain in Active Directory

The first domain created in Active Directory becomes the forest root domain. This is the domain that represents the entire business. It is important to plan which domain will become the forest root domain because, after it is established, it cannot be renamed or deleted without reinstalling Active Directory.

In Chapter 2, "Overview of Active Directory Design Elements," you learned that the forest root domain stores common information that is shared between all domains in the forest. Shared information includes the following:

• Schema

• Configuration container

• Schema Admin

• Enterprise Admin

For a more in-depth discussion of forests, refer to Chapter 2.

Careful planning is required when choosing a name for the forest root domain. The first thing to note is that the forest root domain cannot be renamed. So, if it's decided after the fact that the name chosen is no longer suitable, be ready to spend a lot of time and effort re-creating the Active Directory structure. Second, choosing an appropriate name for the forest root domain is important because all other domains created under the forest root (child domains) will derive a portion of their namespaces from it.

When deciding what to name the first domain in Active Directory, keep the following points in mind:

• Choose a name that will not change in the near future, meaning a name that is static. Changing the name of the forest root domain is not easy, so select a name that will not change in the next 3 “5 years .

• Choose a name that is meaningful to the business, its employees , and its clients . When naming the forest root, consider using the name of the business.

• Be sure the name is available for use on the Internet. Even if the business has no intention of using its name on the Internet, make sure the name is registered in case the business changes its mind in the future.

When creating the forest root domain, the design team might determine that the business's name would be an appropriate choice (as long as the business has no intention of changing the company name in the near future). The name can provide a general representation of the business and an appropriate namespace for child domains in the forest. The company name is also meaningful to employees and clients and makes the domain easily identifiable. For example, the XYZ Corporation shown in Figure 7.1 uses xyz.corp as its forest root domain. The root domain namespace has been passed on to the Training and Consulting child domains.

Figure 7.1. The first domain created is the forest root domain. Its namespace is inherited by all child domains and should therefore be a good representation of the business.