All IP addresses are registered on the DNS servers when the IP addresses are assigned to one network adapter on a computer that is running Windows Server 2008 SP2 or Windows Vista SP2

Consider the following scenario:

• Lots of IP addresses are assigned to one network adapter on a computer that is running Windows Server 2008 Service Pack 2 (SP2) or Windows Vista Service Pack 2 (SP2).
• Only the primary IP address is used for outgoing traffic.

In this scenario, only the primary IP address should be registered on the DNS servers for outgoing communication purpose. However, all IP addresses are registered on the DNS servers.

The issue causes the following symptoms:

• The communication to the computer is blocked by a firewall. Because all IP addresses are registered on the DNS servers, all these IP addresses seem to be valid IP addresses that can be used to communicate with the computer. However, if only the primary IP address can pass through a firewall, communication that uses all other IP addresses is block by the firewall.
• A large amount of DNS registration traffic and a large amount of update traffic is generated. However, this traffic is unnecessary because these IP addresses are not used for outgoing traffic.

This problem occurs because all assigned IP addresses are registered on the DNS servers. This is by default. Additionally, there is no option made available to change this default behavior.

After you install this hotfix, you can create IP version 4 (IPv4) addresses or IP version 6 (IPv6) addresses by using the netsh command together with the new "skipassource" flag. By using this flag, the added new addresses are not used for outgoing packets unless explicitly set for use by outgoing packets. Therefore, these IP addresses will not be registered on the DNS servers.

For example, the following is a netsh command together with the new "skipassource" flag for an IPv4 address:

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, the computer must be running one of the following operating systems:

• Windows Vista Service Pack 2 (SP2)
• Windows Server 2008 Service Pack 2 (SP2)

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfix.

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 item in Control Panel.

For all supported x86-based versions of Windows Server 2008 SP2 and of Windows Vista SP2

For all supported x64-based versions of Windows Server 2008 SP2 and of Windows Vista SP2

For all supported Itanium-based versions of Windows Server 2008 SP2

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

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

Additional file information for Windows Server 2008 and for Windows Vista

Additional files for all supported x86-based versions of Windows Server 2008 and of Windows Vista

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

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