What is Active Directory Domain Services 2008? Active Directory Domain Services (AD DS), formerly known as Active Directory Directory Services, is the central location for configuration information, authentication requests, and information about all of the objects that are stored within your forest. Using Active Directory, you can efficiently manage users, computers, groups, printers, applications, and other directory-enabled objects from one secure, centralized location. What is the SYSVOL folder? The Sysvol folder on a Windows domain controller is used to replicate file-based data among domain controllers. Because junctions are used within the Sysvol folder structure, Windows NT file system (NTFS) version 5.0 is required on domain controllers throughout a Windows distributed file system (DFS) forest. This is a quote from microsoft themselves, basically the domain controller info stored in files like your group policy stuff is replicated through this folder structure What’s New in Windows Server 2008 Active Directory Domain Services? Active Directory Domain Services in Windows Server 2008 provides a number of enhancements over previous versions, including these: Auditing—AD DS auditing has been enhanced significantly in Windows Server 2008. The enhancements provide more granular auditing capabilities through four new auditing categories: Directory Services Access, Directory Services Changes, Directory Services Replication, and Detailed Directory Services Replication. Additionally, auditing now provides the capability to log old and new values of an attribute when a successful change is made to that attribute. Fine-Grained Password Policies—AD DS in Windows Server 2008 now provides the capability to create different password and account lockout policies for different sets of users in a domain. User and group password and account lockout policies are defined and applied via a Password Setting Object (PSO). A PSO has attributes for all the settings that can be defined in the Default Domain Policy, except Kerberos settings. PSOs can be applied to both users and groups. Read-Only Domain Controllers—AD DS in Windows Server 2008 introduces a new type of domain controller called a read-only domain controller (RODC). RODCs contain a read-only copy of the AD DS database. RODCs are covered in more detail in Chapter 6, “Manage Sites and Replication.” Restartable Active Directory Domain Services—AD DS in Windows Server 2008 can now be stopped and restarted through MMC snap-ins and the command line. The restartable AD DS service reduces the time required to perform certain maintenance and restore operations. Additionally, other services running on the server remain available to satisfy client requests while AD DS is stopped. AD DS Database Mounting Tool—AD DS in Windows Server 2008 comes with a AD DS database mounting tool, which provides a means to compare data as it exists in snapshots or backups taken at different times. The AD DS database mounting eliminates the need to restore multiple backups to compare the AD data that they contain and provides the capability to examine any change made to data stored in AD DS.
What is the Global Catalog? A global catalog server is a domain controller. It is a master searchable database that contains information about every object in every domain in a forest. The global catalog contains a complete replica of all objects in Active Directory for its host domain, and contains a partial replica of all objects in Active Directory for every other domain in the forest. It has two important functions: Provides group membership information during logon and authentication Helps users locate resources in Active Directory What are RODCs? And what are the major benefits of using RODCs? A read-only domain controller (RODC) is a new type of domain controller in the Windows Server® 2008 operating system. With an RODC, organizations can easily deploy a domain controller in locations where physical security cannot be guaranteed. An RODC hosts read-only partitions of the Active Directory® Domain Services (AD DS) database. Before the release of Windows Server 2008, if users had to authenticate with a domain controller over a wide area network (WAN), there was no real alternative. In many cases, this was not an efficient solution. Branch offices often cannot provide the adequate physical security that is required for a writable domain controller. Furthermore, branch offices often have poor network bandwidth when they are connected to a hub site. This can increase the amount of time that is required to log on. It can also hamper access to network resources. Beginning with Windows Server 2008, an organization can deploy an RODC to address these problems. As a result, users in this situation can receive the following benefits: * Improved security * Faster logon times * More efficient access to resources on the network What does an RODC do? Inadequate physical security is the most common reason to consider deploying an RODC. An RODC provides a way to deploy a domain controller more securely in locations that require fast and reliable authentication services but cannot ensure physical security for a writable domain controller. However, your organization may also choose to deploy an RODC for special administrative requirements. For example, a line-of-business (LOB) application may run successfully only if it is installed on a domain controller. Or, the domain controller might be the only server in the branch office, and it may have to host server applications. In such cases, the LOB application owner must often log on to the domain controller interactively or use Terminal Services to configure and manage the application. This situation creates a security risk that may be unacceptable on a writable domain controller.
An RODC provides a more secure mechanism for deploying a domain controller in this scenario. You can grant a nonadministrative domain user the right to log on to an RODC while minimizing the security risk to the Active Directory forest. You might also deploy an RODC in other scenarios where local storage of all domain user passwords is a primary threat, for example, in an extranet or application-facing role. What is REPADMIN? Repadmin.exe: Replication Diagnostics Tool This command-line tool assists administrators in diagnosing replication problems between Windows domain controllers. Administrators can use Repadmin to view the replication topology (sometimes referred to as RepsFrom and RepsTo) as seen from the perspective of each domain controller. In addition, Repadmin can be used to manually create the replication topology (although in normal practice this should not be necessary), to force replication events between domain controllers, and to view both the replication metadata and up-to-dateness vectors. Repadmin.exe can also be used for monitoring the relative health of an Active Directory forest. The operations replsummary, showrepl, showrepl /csv, and showvector /latency can be used to check for replication problems. What is NETDOM? NETDOM is a command-line tool that allows management of Windows domains and trust relationships. It is used for batch management of trusts, joining computers to domains, verifying trusts, and secure channels What is the difference between transferring a fsmo role and seizing one which one should you not seize why? Seizing an FSMO can be a destructive process and should only be attempted if the existing server with the FSMO is no longer available. If the domain controller that is the Schema Master FSMO role holder is temporarily unavailable, DO NOT seize the Schema Master role. If you are going to seize the Schema Master, you must permanently disconnect the current Schema Master from the network. If you seize the Schema Master role, the boot drive on the original Schema Master must be completely reformatted and the operating system must be cleanly installed, if you intend to return this computer to the network. NOTE: The Boot Partition contains the system files (\System32). The System Partition is the partition that contains the startup files, NTDetect.com, NTLDR, Boot.ini, and possibly Ntbootdd.sys.
The Active Directory Installation Wizard (Dcpromo.exe) assigns all 5 FSMO roles to the first domain controller in the forest root domain. The first domain controller in each new child or tree domain is assigned the three domain-wide roles. Domain controllers continue to own FSMO roles until they are reassigned by using one of the following methods: • • • An administrator reassigns the role by using a GUI administrative tool. An administrator reassigns the role by using the ntdsutil /roles command. An administrator gracefully demotes a role-holding domain controller by using the Active Directory Installation Wizard. This wizard reassigns any locally-held roles to an existing domain controller in the forest. Demotions that are performed by using the dcpromo /forceremoval command leave FSMO roles in an invalid state until they are reassigned by an administrator.
We recommend that you transfer FSMO roles in the following scenarios: • • • The current role holder is operational and can be accessed on the network by the new FSMO owner. You are gracefully demoting a domain controller that currently owns FSMO roles that you want to assign to a specific domain controller in your Active Directory forest. The domain controller that currently owns FSMO roles is being taken offline for scheduled maintenance and you need specific FSMO roles to be assigned to a "live" domain controller. This may be required to perform operations that connect to the FSMO owner. This would be especially true for the PDC Emulator role but less true for the RID master role, the Domain naming master role and the Schema master roles.
We recommend that you seize FSMO roles in the following scenarios: • • • The current role holder is experiencing an operational error that prevents an FSMO-dependent operation from completing successfully and that role cannot be transferred. A domain controller that owns an FSMO role is force-demoted by using the dcpromo /forceremoval command. The operating system on the computer that originally owned a specific role no longer exists or has been reinstalled.
As replication occurs, non-FSMO domain controllers in the domain or forest gain full knowledge of changes that are made by FSMO-holding domain controllers. If you must transfer a role, the best candidate domain controller is one that is in the appropriate domain that last inbound-replicated, or recently inboundreplicated a writable copy of the "FSMO partition" from the existing role holder. For example, the Schema master role-holder has a distinguished name path of CN=schema,CN=configuration,dc=<forest root domain>, and this mean that roles reside in and are replicated as part of the CN=schema partition. If the domain controller that holds the Schema master role experiences a hardware or software failure, a good candidate role-holder would be a domain controller in the root domain and in the same Active Directory site as the current owner. Domain controllers in the same Active Directory site perform inbound replication every 5 minutes or 15 seconds. The partition for each FSMO role is in the following list:
Collapse this tableExpand this table FSMO role Partition Schema CN=Schema,CN=configuration,DC=<forest root domain> Domain Naming Master CN=configuration,DC=<forest root domain> PDC DC=<domain> RID DC=<domain> Infrastructure DC=<domain> A domain controller whose FSMO roles have been seized should not be permitted to communicate with existing domain controllers in the forest. In this scenario, you should either format the hard disk and reinstall the operating system on such domain controllers or forcibly demote such domain controllers on a private network and then remove their metadata on a surviving domain controller in the forest by using the ntdsutil /metadata cleanup command. The risk of introducing a former FSMO role holder whose role has been seized into the forest is that the original role holder may continue to operate as before until it inboundreplicates knowledge of the role seizure. Known risks of two domain controllers owning the same FSMO roles include creating security principals that have overlapping RID pools, and other problems. Back to the top Transfer FSMO roles To transfer the FSMO roles by using the Ntdsutil utility, follow these steps: 1. Log on to a Windows 2000 Server-based or Windows Server 2003-based member computer or domain controller that is located in the forest where FSMO roles are being transferred. We recommend that you log on to the domain controller that you are assigning FSMO roles to. The logged-on user should be a member of the Enterprise Administrators group to transfer Schema master or Domain naming master roles, or a member of the Domain Administrators group of the domain where the PDC emulator, RID master and the Infrastructure master roles are being transferred. Click Start, click Run, type ntdsutil in the Open box, and then click OK. Type roles, and then press ENTER. Note To see a list of available commands at any one of the prompts in the Ntdsutil utility, type ?, and then press ENTER. Type connections, and then press ENTER. Type connect to server servername, and then press ENTER, where servername is the name of the domain controller you want to assign the FSMO role to. At the server connections prompt, type q, and then press ENTER. Type transfer role, where role is the role that you want to transfer. For a list of roles that you can transfer, type ? at the fsmo maintenance prompt, and then press ENTER, or see the list of roles at the start of this article. For example, to transfer the RID master role, type transfer rid master. The one exception is for the PDC emulator role, whose syntax is transfer pdc, not transfer pdc emulator. At the fsmo maintenance prompt, type q, and then press ENTER to gain access to the ntdsutil prompt. Type q, and then press ENTER to quit the Ntdsutil utility.
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Back to the top Seize FSMO roles To seize the FSMO roles by using the Ntdsutil utility, follow these steps: 1. Log on to a Windows 2000 Server-based or Windows Server 2003-based member computer or domain controller that is located in the forest where FSMO roles are being seized. We recommend that you log on to the domain controller that you are assigning FSMO roles to. The logged-on user should be a member of the Enterprise Administrators group to transfer schema or domain naming
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master roles, or a member of the Domain Administrators group of the domain where the PDC emulator, RID master and the Infrastructure master roles are being transferred. Click Start, click Run, type ntdsutil in the Open box, and then click OK. Type roles, and then press ENTER. Type connections, and then press ENTER. Type connect to server servername, and then press ENTER, where servername is the name of the domain controller that you want to assign the FSMO role to. At the server connections prompt, type q, and then press ENTER. Type seize role, where role is the role that you want to seize. For a list of roles that you can seize, type ? at the fsmo maintenance prompt, and then press ENTER, or see the list of roles at the start of this article. For example, to seize the RID master role, type seize rid master. The one exception is for the PDC emulator role, whose syntax is seize pdc, not seize pdc emulator. At the fsmo maintenance prompt, type q, and then press ENTER to gain access to the ntdsutil prompt. Type q, and then press ENTER to quit the Ntdsutil utility. Notes o Under typical conditions, all five roles must be assigned to "live" domain controllers in the forest. If a domain controller that owns a FSMO role is taken out of service before its roles are transferred, you must seize all roles to an appropriate and healthy domain controller. We recommend that you only seize all roles when the other domain controller is not returning to the domain. If it is possible, fix the broken domain controller that is assigned the FSMO roles. You should determine which roles are to be on which remaining domain controllers so that all five roles are assigned to a single domain controller. For more information about FSMO role placement, click the following article number to view the article in the Microsoft Knowledge Base: 223346 (http://support.microsoft.com/kb/223346/ ) FSMO placement and optimization on Windows 2000 domain controllers If the domain controller that formerly held any FSMO role is not present in the domain and if it has had its roles seized by using the steps in this article, remove it from the Active Directory by following the procedure that is outlined in the following Microsoft Knowledge Base article: 216498 (http://support.microsoft.com/kb/216498/ ) How to remove data in active directory after an unsuccessful domain controller demotion Removing domain controller metadata with the Windows 2000 version or the Windows Server 2003 build 3790 version of the ntdsutil /metadata cleanup command does not relocate FSMO roles that are assigned to live domain controllers. The Windows Server 2003 Service Pack 1 (SP1) version of the Ntdsutil utility automates this task and removes additional elements of domain controller metadata. Some customers prefer not to restore system state backups of FSMO role-holders in case the role has been reassigned since the backup was made. Do not put the Infrastructure master role on the same domain controller as the global catalog server. If the Infrastructure master runs on a global catalog server it stops updating object information because it does not contain any references to objects that it does not hold. This is because a global catalog server holds a partial replica of every object in the forest.
To test whether a domain controller is also a global catalog server: 1. 2. 3. 4. Click Start, point to Programs, point to Administrative Tools, and then click Active Directory Sites and Services. Double-click Sites in the left pane, and then locate the appropriate site or click Default-first-sitename if no other sites are available. Open the Servers folder, and then click the domain controller. In the domain controller's folder, double-click NTDS Settings.
On the Action menu, click Properties. On the General tab, view the Global Catalog check box to see if it is selected.