Datagram loss when you run a multicast receiver application in Windows 8 and in Windows Server 2012

Applies to: Windows Server 2012 DatacenterWindows Server 2012 DatacenterWindows Server 2012 Essentials More


Consider the following scenario:
  • You run a multicast receiver application on a Windows 8-based or a Windows Server 2012-based computer.
  • The application has to receive lots of multicast datagrams on multiple UDP ports. For example, the application receives financial markets pricing information.
  • Datagrams are received at a rate that exceeds the capacity at which the computer can process the datagrams.
In this scenario, the multicast receiver application experiences datagram loss.

Note The capacity of the computer to process multicast datagrams is influenced by many factors. These factors include processor speed, application software design, and network adapter settings.


After this update is installed, the administrator can specify and configure the UDP ports that handle multicast traffic to bypass the base filtering engine. This update also enables the administrator to configure associated processing costs that is specific to multicast datagram reception.

This hotfix is also available at Microsoft Update Catalog.

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 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.


To apply this update, you must be running Windows 8 or Windows Server 2012.

Registry information

After this update is installed, you can create a REG_MULTI_SZ type registry key named UdpExemptPortRange to configure the port ranges that are exempted from the base filtering engine. To do this, create the registry key in the following path:HKEY_LOCAL_MACHINE\System\CurrentControlSet\services\Tcpip\Parameters\
For example, you can configure the following value in the registry key:

The smallest port number to use is 1 and the highest is 65535.

  • Each exempted port range should be in a new line.
  • You must restart the computer after you changed the registry key.

Restart requirement

You must 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.

More Information

The BFE is a service that manages firewall and IPsec policies and implements user mode filtering. Stopping or disabling the BFE service significantly reduces the security of the system. It also results in unpredictable behavior in IPsec management and firewall applications.

The BFE is the core of the new WFP from Windows Vista and Windows Server 2008. And the BFE is required to start the following services appropriately:
  • Internet Key Exchange (IKE) and Authenticated Internet Protocol (AuthIP) IPsec Keying Modules
  • Internet Connection Sharing
  • IPsec Policy Agent
  • Routing and Remote Access
  • Windows Firewall
Note The default startup type of this service is Automatic, and the service should not be disabled.

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