DSCP value is missing in the SYN-ACK packet during a TCP connection in Windows 7 SP1 or Windows Server 2008 R2 SP1

Consider the following scenario:

• You have a computer that is running Windows 7 Service Pack 1 (SP1) or Windows Server 2008 R2 SP1.
• You create a policy to mark specific traffic with the differentiated services code point (DSCP) value on the computer.
• You configure the DSCP marking on the computer.
• You open a transmission control protocol (TCP) connection to the computer.

In this scenario, the SYN-ACK packet from the computer does not have the DSCP value set.

To resolve this issue, we have released a hotfix package for Windows 7 or Windows Server 2008 R2.

Before you install the hotfix, check the Prerequisites section in this article.

Hotfix information for Windows 7 and Windows Server 2008 R2

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, go to the following Microsoft website: 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 Service Pack 1 for Windows 7 or for Windows Server 2008 R2.

Registry information

To apply this hotfix, you do not have to make any changes to the registry.

Restart requirement

You may have to restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

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, see the standard terminology that is used to describe Microsoft software updates.

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 7 and 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, milestone (RTM, SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table:

  Version	Product	Milestone	Service branch
  6.1.760 1.17xxx	Windows Server 2008 R2	SP1	GDR
  6.1.760 1.22xxx	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 7 and Windows Server 2008 R2" section. MUM, MANIFEST, and the associated security catalog (.cat) files, are very 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 x86-based versions of Windows 7

For all supported x64-based versions of Windows 7 and Windows Server 2008 R2

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

Additional file information for Windows 7 and Windows Server 2008 R2

Additional files for all supported x86-based versions of Windows 7

Additional files for all supported x64-based versions of Windows 7 and Windows Server 2008 R2

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