This KB article describes a hotfix that enables Windows Deployment Services in Windows Server 2008 R2 to support the Source Specific Multicast (SSM) protocol. The hotfix must be integrated into Windows 7 or Windows Server 2008 R2 image files (.wim). After the integration, the Source Specific Multicast (SSM) protocol is supported when you use Windows Deployment Services to deploy a Windows 7 or Windows Server 2008 R2 image.
Consider the following scenario in a domain environment:
The network infrastructure supports SSM.
You create a Windows Deployment Services multicast transmission to deploy a Windows 7 or Windows Server 2008 R2 image.
In this scenario, the deployment fails.
This failure occurs because of the multicast packets that client computers send out during the deployment. The packets contain a multicast source address that has a value of "any source" instead of the IP address of the Windows Deployment Services server. This causes the deployment to fail.
After you integrate the hotfix into a Windows 7 or Windows Server 2008 R2 image file, the value of multicast source address is set correctly to the IP address of the Windows Deployment Services server.
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 website:
How to integrate this hotfix into the Boot.wim file
Extract the Windows6.1-KB2495879-x64.cab file from the hotfix package. Assume that you save the Windows6.1-KB2495879-x64.cab file to the C:\Test\Updates folder.
Copy the Boot.wim file to a folder for update. Assume that the folder is C:\Test\Images. Note If you want to use the Out-of-box Boot.wim file, that file is located in the Sources folder of the Windows 7 or Windows Server 2008 R2 installation media.
Create a folder to mount images. Assume that the folder is C:\Test\Offline.
Open a Command Prompt window by using the Run as administrator option.
Run the following command to mount the second image of the Boot.wim file:
Important The value of the AllowSSM registry entry is necessary to make Windows Deployment Services support SSM. To verify that this value is set correctly, follow these steps:
Start a client computer by using this updated Boot.wim file.
Use SHIFT+F10 to open a Command Prompt window.
Type regedit, and then press ENTER.
In Registry Editor, verify that the value of the AllowSSM registry entry is set to 1.
You do not have to restart the computer after you apply this hotfix.
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 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, SR_Level (RTM, SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table.
6.1.760 0. 20xxx
Windows 7 and Windows Server 2008 R2
6.1.760 1. 21xxx
Windows 7 and Windows Server 2008 R2
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 the x86-based version of Windows 7 boot images
For the x64-based version of Windows 7 boot images and of Windows Server 2008 R2 boot images
For the IA-64-based version of Windows Server 2008 R2 boot images
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:
824684 Description of the standard terminology that is used to describe Microsoft software updates
Additional file information
Additional file information for Windows 7 and for Windows Server 2008 R2
Additional files for the x86-based version of Windows 7 boot images