Familiarize yourself with Active Directory's five FSMO roles

In addition to these differences, it's also important to understand the various Flexible Single Master Operations (FSMO) roles in Active Directory that a domain controller can hold.

While Active Directory is a distributed system, some servers only carry out specific roles. If something happens to this server or you need a more substantial server to handle a particular role, you must know which servers are handling each role.

There are five FSMO roles:

• PDC emulator (one per domain): This role allows Windows Server 2003 to act as a Windows NT primary domain controller (PDC), and it provides replication support for Windows NT-based backup domain controllers (BDCs). In addition, this role assists with time and group policy synchronization.
• Infrastructure master (one per domain): This role is responsible for updating the group-to-user references whenever the members of groups change or receive new names.
• Relative ID (RID) master (one per domain): This role ensures that every object created has a unique identification number.
• Schema master (one per forest): This role is responsible for maintaining and modifying the Active Directory schema.
• Domain naming master (one per forest): This role is responsible for the addition and deletion of domains in a forest.

How can you determine which servers hold these roles in an Active Directory forest? To find the PDC emulator, the infrastructure master, and the RID master, follow these steps:

1. Go to Start | Administrative Tools | Active Directory Users And Computers.
2. Right-click the domain, and select Operations Master.

The resulting three tabs will show you which server holds each respective role.

To find the schema master, follow these steps:

1. Go to Start | Run.
2. Enter regsvr32 schmmgmt.dll in the Open text box, and click OK.
3. Go to Start | Run.
4. Enter mmc in the Open text box, and click OK.
5. Go to File | Add/Remove Snap-In, and click Add.
6. Click Active Directory Schema, click Add, click Close, and click OK.
7. Right-click Active Directory Schema, and select Operations Master from the shortcut menu.

To find the domain naming master, follow these steps:

1. Go to Start | Administrative Tools | Active Directory Domains And Trusts.
2. Right-click Active Directory Domains And Trusts, and select Operations Master from the list.

Each option features a Change button, which allows you to move the role to another domain controller.