DNS Server service randomly cannot resolve external names and returns a "Server Failure" error if IPv6 is disabled in Windows Server 2008 R2

Consider the following scenario:

• You install the DNS Server role on a computer that is running Windows Server 2008 R2.
• You disable IP version 6 (IPv6) on the computer.
• You configure the DNS server to use root hints to resolve external name resolution.
• The DNS Server service receives some external name resolution requests.
  

In this scenario, the DNS Server service randomly returns the following error message:
Additionally, users cannot access some Internet network resource if they use the DNS server to resolve external names.

For example, users cannot access some websites.

Note If you collect a network trace when this issue occurs, the trace contains the following network packets:

This issue occurs because the DNS Server service does not check whether IPv6 is disabled when the service selects an IP address to send the next DNS query.

When the DNS Server service queries the name server for an external name resolution request, the Internet DNS server returns an IP address list that contains IP version 4 (IPv4) and IPv6 addresses. However, the DNS Server service does not check whether IPv6 is disabled when the service selects an IP address to send the next DNS query. The service may select an IPv6 address when IPv6 is disabled. Therefore, the DNS Server service does not send the next DNS query, and this issue occurs.

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

To apply this hotfix, you must be running one of the following operating systems:

• Windows Server 2008 R2
• Windows Server 2008 R2 Service Pack 1 (SP1)

Additionally, the DNS Server role must be installed.

For more information about how to obtain a Windows Server 2008 R2 service pack, click the following article number to view the article in the Microsoft Knowledge Base:

Registry information

To use the hotfix in this package, you do not have to make any changes to the registry.

Restart requirement

You do not have to restart the computer after you apply this hotfix.

You must stop the DNS Server service before you apply this hotfix to avoid restarting.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

File information

The global version of this hotfix installs files that have the attributes that are listed in the following tables. The dates and the times for these files are listed in Coordinated Universal Time (UTC). The dates and the times for these files on your local computer are displayed in your local time together with your current daylight saving time (DST) bias. Additionally, the dates and the times may change when you perform certain operations on the files.

Windows Server 2008 R2 file information notes

Important Windows 7 hotfixes and Windows Server 2008 R2 hotfixes are included in the same packages. However, hotfixes on the Hotfix Request page are listed under both operating systems. To request the hotfix package that applies to one or both operating systems, select the hotfix that is listed under "Windows 7/Windows Server 2008 R2" on the page. Always refer to the "Applies To" section in articles to determine the actual operating system that each hotfix applies to.

• The files that apply to a specific product, SR_Level (RTM, SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table.
  Collapse this tableExpand this table

  Version	Product	SR_Level	Service branch
  6.1.760 0 . 20xxx	Windows Server 2008 R2	RTM	LDR
  6.1.760 1 . 21xxx	Windows Server 2008 R2	SP1	LDR

• The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separately in the "Additional file information for Windows Server 2008 R2" section. MUM and MANIFEST files, and the associated security catalog (.cat) files, are extremely important to maintain the state of the updated components. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.

For all supported x64-based versions of Windows Server 2008 R2

To work around this issue, enable IPv6 on the DNS Server service.

For more information about how to enable IPv6, click the following article number to view the article in the Microsoft Knowledge Base:

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base: For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Additional file information

Additional file information for Windows Server 2008 R2

Additional files for all supported x64-based versions of Windows Server 2008 R2