Authentication requests between nodes in the same failover cluster may be unable to use the Kerberos protocol if the Negotiate SSP is specified in Windows Server 2008 R2

Authentication requests that use the Negotiate SSP may be unable to use the Kerberos protocol to access resources. This occurs when the request is made from one node in a failover cluster to another node in the same failover cluster. In this situation, NTLM is used as the authentication protocol that cannot perform the delegation.

The following is an example scenario:

• You install an instance of Microsoft SQL server on a node.
• You install another instance of SQL Server on another node.
• In the first instance, you create a linked server that targets the second instance.
• The cluster resource group which includes the second instance is failed over to the first node. Then, the cluster resource group is moved to the second node.
• You access databases in the second instance on the first node by using a linked server configuration.

In this scenario, anonymous access is used to access the linked database unexpectedly. Therefore, inconsistent data results are returned.

This issue occurs because the target clustered resource DNS name is not removed from the local name table that is maintained by the Local Security Authority (LSA). This happens when the cluster resource is transitioned into an offline state.

When a cluster resource is transitioned into an online state on a node, the Cluster service registers its DNS name and NetBIOS name into a table that is maintained by LSA. This table contains the names of all the cluster resources that are hosted on the Cluster node locally.

The registration of the DNS names is a new functionality in Windows Server 2008. Previously, only the NetBIOS names were registered.

When an application on the cluster node calls the InitializeSecurityContext function to start authentication with a service and the Negotiate SSP is used, LSA checks the local names table for the target name. If the target name exists in the local names table, LSA uses optimization to service the request. The optimization is used because the target resource is local. Therefore, is not necessary to build Kerberos authentication data to send to a remote host.

When a cluster resource enters the offline state on the node, the DNS name is not removed from the table. In this situation, LSA considers the resource to be hosted on the local node. However, the resource is hosted on a remote node.

If LSA uses the optimization, and if the target service is not located on the local node, NTLM will be used to authenticate to the remote host. This results in a failure in the delegation and the impersonation on the remote host will be created under the anonymous context. Therefore, the access to the cluster resources may fail or there is insufficient access to return the expected results.

After you apply this hotfix, the NetBIOS and DNS names will be removed from the local names table when the resource transitions into an offline state.

This hotfix also removes a dependency upon DNS name registration that may stop the local names table being updated. After you apply this hotfix, the DNS and NetBIOS names will be added or removed from the local names table regardless of DNS name registration.

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 the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

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, contact 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 Windows Server 2008 R2. Additionally, you must have the "Failover Clustering" feature installed.

Restart requirement

You must restart the computer after you apply this hotfix.

Note To avoid restarting the computer, stop the Cluster service before you apply the hotfix.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

File information

The English (United States) 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

• 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 and for Windows 7" 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

For all supported IA-64-based versions of Windows Server 2008 R2

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 about a similar issue in Windows Server 2008 R2, 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

Additional files for all supported IA-64-based versions of Windows Server 2008 R2