Cooking with Active Directory

by Robbie Allen
09/22/2003

Related Reading Active Directory Cookbook By Robbie Allen

Editor's note: Active Directory Cookbook contains hundreds of step-by-step solutions for common and uncommon problems system administrators encounter with Active Directory. To provide a sense of the kind of examples you'll find in the book, we present two sample recipes: the first from Chapter 3, "Domain Controllers, Global Catalogs, and FSMOs" and the second from Chapter 6, "Users."

Recipe 3.25: Finding the FSMO Role Holders

Problem

You want to find the domain controllers that are acting as one of the FSMO roles.

Solution

Using a graphical user interface

For the Schema Master:

1. Open the Active Directory Schema snap-in.
2. Right-click on Active Directory Schema in the left pane and select Operations Master.

For the Domain Naming Master:

1. Open the Active Directory Domains and Trusts snap-in.
2. Right-click on Active Directory Domains and Trusts in the left pane and select Operations Master.

For the PDC Emulator, RID Master, and Infrastructure Master:

1. Open the Active Directory Users and Computers snap-in.
2. Make sure you've targeted the correct domain.
3. Right-click on Active Directory Users and Computers in the left pane and select Operations Master.
4. There are individual tabs for the PDC, RID, and Infrastructure roles.

Using a command-line interface

In the following command, you can leave out the /Domain <DomainDNSName> option to query the domain you are currently logged on.

> netdom query fsmo /Domain:<DomainDNSName>

For some reason, this command returns a "The parameter is incorrect" error on Windows Server 2003. Until that is resolved, you can use the dsquery server command shown here, where <Role> can be schema, name, infr, pdc, or rid:

> dsquery server -hasfsmo <Role>

Using VBScript

' This code prints the FSMO role owners for the specified domain.
' ------ SCRIPT CONFIGURATION ------
strDomain = "<DomainDNSName>"  ' e.g. emea.rallencorp.com
' ------ END CONFIGURATION ---------
 
set objRootDSE = GetObject("LDAP://" & strDomain & "/RootDSE")
strDomainDN  = objRootDSE.Get("defaultNamingContext")
strSchemaDN = objRootDSE.Get("schemaNamingContext")
strConfigDN = objRootDSE.Get("configurationNamingContext")
 
' PDC Emulator
set objPDCFsmo = GetObject("LDAP://" & strDomainDN)
Wscript.Echo "PDC Emulator: " & objPDCFsmo.fsmoroleowner
 
' RID Master
set objRIDFsmo = GetObject("LDAP://cn=RID Manager$,cn=system," _
                           & strDomainDN)
Wscript.Echo "RID Master: " & objRIDFsmo.fsmoroleowner
 
' Schema Master
set objSchemaFsmo = GetObject("LDAP://" & strSchemaDN)
Wscript.Echo "Schema Master: " & objSchemaFsmo.fsmoroleowner
 
' Infrastructure Master
set objInfraFsmo = GetObject("LDAP://cn=Infrastructure," _ 
                             & strDomainDN)
Wscript.Echo "Infrastructure Master: " & objInfraFsmo.fsmoroleowner
 
' Domain Naming Master
set objDNFsmo = GetObject("LDAP://cn=Partitions," & strConfigDN)
Wscript.Echo "Domain Naming Master: " & objDNFsmo.fsmoroleowner 

Discussion

Several Active Directory operations are sensitive, such as updating the schema, and therefore, need to be done on a single domain controller. Active Directory cannot guarantee the proper evaluation of these functions in a situation where they may be invoked from more than one DC. The FSMO mechanism is used to limit these functions to a single DC.

There are five designated FSMO roles that correspond to these sensitive functions. A FSMO role can apply either to an entire forest or to a specific domain. Each role is stored in the fSMORoleOwner attribute on various objects in Active Directory depending on the role. Table 3-4 contains a list of FSMO roles.

Table 3-4: FSMO roles

Role	Description	fSMORoleOwner Location	Domain or Forest-wide?
Schema	Processes schema updates	CN=Schema,CN=Configuration,<ForestDN>	Forest
Domain Naming	Processes the addition, removal, and renaming of domains	CN=Partitions,CN=Configuration,<ForestDN>	Forest
Infrastructure	Maintains references to objects in other domains	CN=Infrastructure,<ForestDN>	Domain
RID	Handles RID pool allocation for the domain controllers in a domain	CN=Rid Manager$, CN=System,<DomainDN>	Domain
PDC Emulator	Acts as the Windows NT master browser and also as the PDC for downlevel clients and Backup Domain Controllers (BDCs)	<DomainDN>	Domain

Using VBScript

If you want to get the DNS name for each FSMO, you'll need to get the parent object of the nTDSDSA object and use the dNSHostName attribute, similar to "Finding the Domain Controllers for a Domain." The code for getting the Schema Master could be changed to the following to retrieve the DNS name of the DC:

set objSchemaFsmo = GetObject("LDAP://cn=Schema,cn=Configuration," _
                                         & strForestDN)
set objSchemaFsmoNTDS = GetObject("LDAP://" & objSchemaFsmo.fsmoroleowner)
set objSchemaFsmoServer = GetObject(objSchemaFsmoNTDS.Parent)
Wscript.Echo "Schema Master: " & objSchemaFsmoServer.Get("dNSHostName")

See Also

MS KB 197132 (Windows 2000 Active Directory FSMO Roles), MS KB 223346 (FSMO Placement and Optimization on Windows 2000 Domain Controllers), MS KB 234790 (HOW TO: Find Servers That Hold Flexible Single Master Operations Roles), and MS KB 324801 (HOW TO: View and Transfer FSMO Roles in Windows Server 2003)

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