An update for Windows Server makes it possible to put the logon server at the top of the DFS referrals list

This article describes an update to Microsoft Windows Server 2003 and Microsoft Windows 2000 Server. The functionality is built into newer versions of Windows Server. This update makes it possible to configure the order of domain controllers that are displayed in the list of Microsoft Distributed File System (DFS) referrals. These referrals are returned to a client computer for the system volume. This update makes it possible to put the logon server at the top of the list.�

Windows Server Active Directory group policies are stored in the system volume network share. The system volume is a domain-based DFS root, and each domain controller in the domain hosts a link replica of the share. To locate the system volume, a client computer queries the logon server for a list of DFS link replicas. The logon server returns a list of all servers in DFS that host the system volume. This list is in random order. Servers that are located in the same site that the client computer is located in are put at the top of the list. A user can be authenticated by one domain controller, and can download policies from another domain controller in the site.

The update that is described in this article modifies the default behavior. After you apply this update, the logon server is added to the top of the list of DFS referrals for the system volume that is returned to the client computer. To use the feature that is included in the update, you must edit the registry. To do this, see the "Edit the registry to use this feature" section.

After you enable the PreferLogonDC registry setting, a domain controller always sorts its own entry to the top of the DFS referral list for the SYSVOL and NETLOGON shares. This can be verified by using the dfsutil /pktinfo command and by using the Netlogon debug log. To generate the Netlogon debug log, at a command prompt, type the following command, and then press ENTER: For more information about the "DsGetDCName" API and about how domain controllers are located, click the following article number to view the article in the Microsoft Knowledge Base: For more information about DFS referral ordering, visit the following Microsoft Web site: Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:

Windows Server 2003 hotfix information

A supported feature that modifies the default behavior of the product is available from Microsoft. However, this feature is intended to modify only the behavior that this article describes. Apply this feature only to systems that specifically require it. This feature might receive additional testing. Therefore, if the system is not severely affected by the lack of this feature, we recommend that you wait for the next software update that contains this feature.

If the feature is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the feature.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific feature. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the feature is available. If you do not see your language, it is because the feature is not available for that language.

Prerequisites

This hotfix should be installed on domain controllers with high priority SRV records.

Restart requirement

You must restart your computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.

Windows Server 2003, 32-bit editions

Windows Server 2003, Enterprise Edition for Itanium-based Systems

Windows 2000 hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, submit a request to Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Prerequisites

This hotfix requires Windows 2000 Service Pack 4 (SP4). This hotfix should be installed on domain controllers with high priority SRV records.

Restart requirement

You must restart your computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.

Edit the registry to use this feature

To use the feature that is described in this article, add the PreferLogonDC registry entry to the registry subkey on each domain controller that you plan to update, set the value of the PreferLogonDC registry entry to 1, and then restart the domain controller. We recommend that you modify the registry before you install the hotfix so that you only have to restart your computer one time.

To add the PreferLogonDC registry entry and set the PreferLogonDC registry entry to 1, follow these steps:

1. Click Start, click Run, type regedit in the Open box, and then click OK.
2. Locate and then click the following registry subkey:
   HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Dfs
3. On the Edit menu, point to New, and then click DWORD Value..
4. Type PreferLogonDC, and then press ENTER.
5. On the Edit menu, click Modify.
6. In the Value data box, type 1, and then click OK
7. Quit Registry Editor.

For more information about how hotfix packages are named, click the following article number to view the article in the Microsoft Knowledge Base: For more information about the standard terminology that is used to describe Microsoft software updates, click the following article number to view the article in the Microsoft Knowledge Base: