The Windows Server 2003 Active Directory Domain Rename Tools provide a secure and supported methodology to rename one or more domains in a deployed Active Directory forest. The DNS name and/or the NetBIOS name of a domain can be changed using the domain rename procedure.
This functionality is not available in Microsoft Windows 2000 Server family.
Note: Windows Server 2000 AD Domains CAN be renamed if they are still in Mixed mode
Microsoft Windows Server 2003 family provides the capability to rename domains in an Active Directory forest after the forest structure is in place. The structure of an Active Directory forest is the result of the order in which you create domains and the hierarchical names of those domains. Beginning with the forest root domain, all child domains derive their distinguished names and default DNS names from the forest root domain name. The same is true of every additional tree in the forest. The way to change the hierarchical structure of an existing domain tree is to rename the domains.
For example, you can rename a child domain to have a different parent, or rename a child domain to be a new tree-root domain. In each case, you reposition an existing domain to create a different domain-tree structure. Alternatively, you can rename domains without affecting the structure. For example, if you rename a root domain, the names of all child domains below it are also changed, but you have not created a different domain-tree structure.
In Windows Server 2003, the goal of the domain rename functionality is to ensure a supported method to rename domains when necessary; it is not intended to make domain rename a routine operation. Thus, although renaming domains is possible in Windows Server 2003, the process is complex and should not be undertaken lightly.
Constraints to Restructuring Domains in a Windows 2000 Forest
The restructuring capabilities in a Windows Server 2003 forest provide solutions to problems that are not addressed in Windows 2000 Server family. In a Windows 2000 forest, renaming domains is essentially not possible after the forest structure is in place without moving domain contents or recreating them. The constraints associated with making domain name changes or domain-tree restructuring in Windows 2000 Active Directory are prohibitive.
In a Windows 2000 forest, you cannot:
Change the DNS name or the NetBIOS name of a domain. Although you cannot rename a domain, you can achieve the same results by moving its contents into a new domain that has the name you want the existing domain to have. (Active Directory Object Manager (MoveTree) in the Windows 2000 Server family Support Tools can be used to move directory objects between domains.)
Move a domain within a forest in a single operation. As above, you can clone items in and move items from a domain, but you cannot move the entire domain itself within a forest.
Split a domain into two domains in a single operation. To split a domain, you must create a new domain and then move appropriate users and resources from the existing domain into the new domain.
Merge two domains into a single domain in a single operation. To merge domains, you must move all the contents from one of the domains into the other and then demote all domain controllers in the empty domain and decommission it.
Thus, in a Windows 2000 forest, significant administrative overhead is associated with performing such manual move operations to achieve the domain-tree restructuring or renaming one or more domains.
Constraints to Restructuring Domains in a Windows Server 2003 Forest:
Windows Server 2003 family provides tools with which you can safely rename domains to restructure a Windows 2003 forest. When making a decision about whether to restructure an existing Windows Server 2003 forest, be sure to consider what you cannot do with forest restructuring. Although a Windows 2003 forest has forest restructuring capability, certain types of structural changes are not supported.
In a Windows Server 2003 forest, you cannot:
Change which domain is the forest root domain. Changing the DNS or the NetBIOS name of the forest root domain, or both, is supported.
Drop domains from the forest or add domains to the forest. The number of domains in the forest before and after the rename/restructure operation must remain the same.
Rename a domain with the same name that another domain gave up in a single forest restructure operation.