Sometimes renaming a domain is an essential business requirement. There are many situations, such as mergers, change of company name or migration from a test environment to a production environment, that require you to change the existing domain name.
However, changing a domain name in Windows Server 2000 is not a simple or straightforward process. It is a time consuming and complex procedure, which requires extensive work.
The renaming of a Windows 2000 domain may impact other server applications that are running in the domain, such as Exchange Server and other custom applications that are closely integrated with Active Directory and use hard coded NETBIOS names.
The major task in renaming a domain is to revert the Windows Server 2000 to Windows NT and then upgrade it to Windows Server 2000 with a new DNS (FQDN) name. If there is more than one domain controller in the domain then all the Windows 2000 domain controllers must be demoted to member servers before renaming the desired domain controller.
Renaming the Windows 2000 domain is only possible if the default functional level of the domain is set to mixed mode. The Windows 2000 mixed mode function level means that there is at least one NT 4.0 BDC in the domain/Forest. The functional level of the domain must be in mixed mode because you need use NT 4.0 BDC to complete the renaming procedure.
Note: If the default functional level of the domain is set to native mode, you cannot revert to mixed mode and cannot rename the domain.
If you have one or more child domains then you have to downgrade all the child domains to Windows NT before downgrading the parent domain. You need to then upgrade the parent domain with new FQDN and then upgrade the child domain/s.
Steps To Be Taken
To rename a Windows 2000 domain, you need to follow these steps:
1. Verify that at least one Windows NT 4.0 BDC, having Service Pack 6 or 6a installed on it, exists in the domain.
2. Backup all the domain controllers in the domain.
3. If required, install another Windows NT 4.0 BDC in the domain and force replication to ensure that the backup of all the security information, domain user accounts and SAM database exists. You can use net accounts /sync command on the Windows NT 4.0 BDC to force replication.
4. If you have just one domain controller, simply isolate it from the network by removing all the cables.
If you have more than one domain controller, you need to demote all the Windows 2000 domain controllers to member servers, leaving just one Windows 2000 domain controller, by using dcpromo command.
Then isolate the last Windows 2000 domain controller after ensuring that a Windows NT 4.0 BDC is present on the network.
5. Demote the last Windows 2000 domain controller by using dcpromo command ensuring that the last domain controller option is selected as the domain option.
Note: To run dcpromo command on the last Windows 2000 domain controller, connect it to an isolated active hub because dcpromo command requires an active connection.
6. Promote Windows NT BDC to a PDC and then upgrade it to Windows 2000.
7. Provide the desired domain name at the time of Active Directory installation.
8. Promote all the demoted member servers back to Windows 2000 domain controllers by running dcpromo on them.
In this article we have seen the different scenarios and methods of renaming a Windows 2000 domain. We have learnt that renaming a Windows 2000 domain is a fairly complex process. We must keep in mind that changing domain name in Windows 2000 should not be performed unless it is absolutely necessary.
Careful planning while deciding on the FQDN/DNS name of the Windows 2000 domain at the time of installation can avoid the trouble of renaming a Windows 2000 domain.
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About the writers
GFI Software provides the single best source of network security, content security and messaging software for small to medium sized businesses.
Alan Drury is member of the Firewall.cx team and senior engineer at a large multinational company, supporting complex large Windows networks.
Chris Partsenidis is a CCNA certified Engineer, MCP, LCP, Founder & Senior Editor of Firewall.cx