Planning Domain Upgrade

After you have considered the issues involving your domain migration and created a plan for resolving any problems that arise, you are ready to begin planning for the actual upgrade process.

Note

You must complete the design of your Windows 2000 forest before you plan your upgrade. For information about designing this forest, see "Designing the Active Directory Structure" in this book.

Domain upgrade is the process of upgrading the PDC and the BDCs in a Windows NT domain from Windows NT Server to Windows 2000 Server. Upgrading is the easiest and lowest risk migration route because it retains most of your system settings, preferences, and program installations.

Because Windows 2000 Server is designed to support mixed networks with full interoperability, you do not have to upgrade all servers in a domain to take advantage of Windows 2000 features. Consider the upgrade to your PDC as simply the first stage in the process; you will gain additional, incremental benefits by upgrading your BDCs, and then your member servers.

Because migration involves an operating system upgrade rather than a new installation, the existing domain structure, users, and groups are maintained, though Windows 2000 features are enabled in the process. When you have completed your upgrade and have access to advanced Windows 2000 management tools and features, you might want to consider restructuring your domains. Be aware, however, that domain restructure is not a trivial task. If structural change is one of your goals, consider performing a domain restructure during the initial migration phase rather than after an upgrade. But consider both options carefully before you move forward.

A domain upgrade accomplishes the following:

• Maintains access to Windows NT domains through existing Windows NT trust relationships

• Maintains access to Windows NT servers and to Windows 95 and Windows 98 clients. This access is transparent to users at client computers.

• Maintains user account passwords so that users log on to the same account domain using the same password.

When planning an upgrade, you need to do the following:

• Determine which upgrade paths are supported.

• Examine your existing domain structure.

• Develop a recovery plan.

• Determine the order for upgrading domains.

• Determine your strategy for upgrading domain controllers.

• Determine when to switch to native mode.

Note

You do not need to upgrade your server infrastructure to Windows 2000 Server before upgrading clients. You can even upgrade clients and member servers before upgrading domain controllers, but you will not be able to access the features of Active Directory until you upgrade your domain controllers.