Planning and Implementing Name Resolution When Migrating

During a migration or while maintaining coexistence during a domain consolidation, it is important to maintain effective and proper name resolution between the source Windows NT 4.0 domain and the destination Active Directory domain.

Planning and managing effective name resolution ensures that server-to-server communications and client server communication are not disrupted. Another area of importance is ensuring third-party applications that are dependent on server name resolution continue to function properly. Review the different name resolution options in the following section to meet your organization's migration requirements.

Understanding Name Resolution with Windows 2003

The solution for managing this task is best determined by understanding the different method in which each of the Microsoft Windows operating systems perform name resolution when querying a host name lookup.

The Windows NT Server 4.0 operating system along with many legacy applications rely primarily on the Windows Internet Naming Services (WINS) built into Windows NT 4.0. When a Windows NT Server requests a host name lookup, NetBIOS name resolution is used to query the domain's WINS. This is the primary means of resolving host names to network addresses with Windows NT 4.0 unless other methods of name resolution are configured to override this method. This method also works with Windows 95, Windows 98, and Windows NT client desktops.

Unlike Windows NT 4.0, Windows Server 2003 and Active Directory rely on the Domain Naming System (DNS) standard as their primary method of name resolutions . This functionality is mandatory and required for the installation of Active Directory. When implementing Windows Server 2003, this becomes the primary method of host name resolution for Windows Server 2003 and Active Directory.

To maintain effective server-to-server and client-server communications when migrating to Windows Server 2003, it is important to consider and design which domain will be responsible for providing name resolution and how name resolution will be affected when the source domain is decommissioned.

Implementing WINS in a Mixed Mode Environment

When integrating Windows Server 2003 and Windows NT Server environments, domain controllers must be able to communicate via their NetBIOS name as well as Fully Qualified Domain Name (FQDN). To implement effective name resolution, it is often a good decision to migrate the Windows NT 4.0 primary WINS services to the newly created destination Active Directory Domain. By migrating WINS services to the destination Active Directory domain, name resolution can be maintained during the migration as well as during the decommissioning of the source Windows NT domain and servers.

Implementing a New Installation of WINS Services in the Destination Domain

Implementing a new installation of WINS Services in the destination domain requires reconfiguring the TCP/IP WINS properties for all servers and clients in the source domain.

Disable the source domain's WINS Service using the services Control Panel. Maintain one installation of WINS as a means of redundancy in case a problem were to appear requiring a fallback to the original WINS server.

Installing WINS

To install WINS on the Windows 2003 Server platform, open the Control Panel and perform the following steps:

From the Windows 2003 Server, select Start, Control Panel, Add Remove Programs.
Select Add/Remove Windows Components.
Select Network Services and click the Details tab.
Select the Windows Internet Naming Services (WINS) and click OK. This installs WINS on the server. Management of the WINS can be completed through the Windows Administrative tools.

Incorporating the Installation and Configuration of Windows 2003 WINS into the Migration Project Plan

Incorporate the installation and configuration of Windows 2003 WINS into the migration project plan. Installing and configuring the service when building the domain controller to replicate information can allow the service to function properly for a period of time prior to beginning to migrate domain users and resources.

Decommissioning Windows 2003 Internet Naming Services

After all domain users and resources have been migrated to the destination Active Directory domain, you can begin to decommission unneeded WINS services previously required for coexistence with the Windows NT 4.0 source domain.

To begin, review the current state of the Windows Server 2003 domain controller's Domain Name Systems logs in the server event viewer to identify any potential DNS name resolution issues. Address and resolve any errors prior to removing the WINS service.

To decommission WINS in an Active Directory environment, changes must take place on the Windows clients as well as all servers in the domain. In every scenario, servers and workstations must be modified to remove old WINS entries from the TCP/IP properties of the system and optimize configuration.

Changing Windows 2003 Server WINS TCP/IP Properties

Best practice is to start with the modifications of network servers, choosing a server that has little to no impact on the network. Modify the TCP/IP properties of the server and test access to network resources. Then continue modifying WINS TCP/IP properties on the remaining servers in your network.

Best Practices for Modifying Workstation WINS Properties

Modifying workstation TCP/IP properties can be much more difficult if an organization has not implemented Dynamic Host Configuration Protocol (DHCP) to distribute network addresses to client workstations.

If your organization is using DHCP, you can modify and remove WINS server entries in the client TCP/IP configuration by modifying the DHCP scope at the server level. This modification can be made at any time with little to no impact on the end user community.

Removing Windows 2003 WINS Services

After all WINS-dependant areas have been addressed, it is now time to uninstall WINS service from the Windows 2003 Server. To complete this task, follow these steps:

Open the Control Panel of the server and open the Add/Remove Programs tool.
Select the Add/Remove Windows Components and choose Networking Services from the Selections dialog box.
Click the Details button to review the networking services options and deselect the WINS component.
Select Finish and close Add/Remove Programs to complete the removal of WINS services.

Testing Name Resolution

Modify a workstation's TCP/IP properties and test name resolution prior to implementing an enterprisewide DHCP configuration change.

Test all server-to-server communications and applications requiring name resolution to ensure that functionality will not be affected when decommissioning WINS services.

Use the Services Control Panel to stop the WINS Service and test name resolution functionality before removing the WINS service and database.