Link Local ISATAP addresses are not generated for the virtual IP used by the NLB feature on a computer that is running Windows Server 2008 R2

Symptoms

Link Local ISATAP addresses are not created for the virtual IP address used by the Network Load Balancing (NLB) feature on a computer that is running Windows Server 2008 R2. This hinders the usage of NLB nodes as a ISATAP router.

Cause

This problem occurs because the IP Helper service does not let virtual IP address interfaces generate ISATAP tunneled addresses or 6to4 tunneled addresses as designed.

For the DIP address ( Dedicated IP ) you will have an ISATAP address available but for the VIP ( Virtual IP ) there is no possibility of having Global Addresses support for the NLB VIP address ( Virtual IP) and no ISATAP addresses can be configured for a VIP.

Resolution

After you apply this hotfix, Link Local ISATAP addresses (FE80::5EFE:'IPv4 address') are generated for the virtual IP addresses and therefore the NLB cluster can act as a ISATAP router. A Link Local ISATAP address is sufficient to act as a ISATAP router because the default route on ISATAP hosts always points to the Link Local ISATAP address of the ISATAP router.

There are no global routable ISATAP addresses (200x::5EFE:'IPv4 address') generated for the virtual IP addresses. This is expected.

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:

http://support.microsoft.com/contactus/?ws=supportNote 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.

Status

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

More Information

For more information about ISATAP tunneled addresses, visit the following Microsoft Web site:

http://www.microsoft.com/download/details.aspx?FamilyId=B8F50E07-17BF-4B5C-A1F9-5A09E2AF698B&displaylang=enFor more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates