A virtual machine that is configured to use the DLC protocol does not connect to an SNA host on Hyper-V Server 2012 or Hyper-V Server 2012 R2

Applies to: Hyper-V Server 2012Windows Server 2012 DatacenterWindows Server 2012 Datacenter More


You use Microsoft Hyper-V Server 2012 or Microsoft Hyper-V Server 2012 R2 to host a virtual machine such as for Microsoft Host Integration Server 2009. If the virtual machine is configured to use the Data Link Control (DLC) protocol to connect to a Systems Network Architecture (SNA) host such as an IBM Mainframe z/OS system, the connection fails.


This problem occurs because Hyper-V Server 2012 and Hyper-V Server 2012 R2 do not support 802.3 frame types that do not have a Sub-Network Access Protocol (SNAP) header.


Hotfix information

A supported hotfix is available from Microsoft Support. 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.


To apply this hotfix, you must have the following installed:
  • Microsoft Hyper-V Server 2012 or Microsoft Hyper-V Server 2012 R2
  • Windows Server 2012 or Windows Server 2012 R2

Restart requirement

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

Hotfix replacement information

This hotfix does not replace any previously released hotfix.


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


See the terminology  that Microsoft uses to describe software updates for more information.