none
How to add a Hyper-V Virtual Switch on Server 2012 R2 w/ already-teamed NICs

    Question

  • Can someone help me understand how to add an external Virtual Switch?

    I have a single server domain using Server 2012 R2 and the server is already configured with dual NICs, teamed using Aggregation. I just added Hyper-V, but when I add an external Virtual Switch using the already-teamed NIC (with Allow management OS to share this network adapter checked), the host server loses LAN connectivity. When I remove the new Virtual Switch, connectivity is restored. Evidently, there's an incompatibility that I'm not understanding.

    I'm wondering if the problem is that my dual NICs were teamed prior to adding Hyper-V and the Virtual Switch?

    Perhaps I need to un-Team the dual NICs and then configure Teaming from w/in the Hyper-V Manager wizard?

    Note: I don't want 1 NIC dedicated to the host and the 2nd NIC dedicated to VMs. I prefer having the 2 physical NICs teamed for aggregation and then shared between the host and the VMs. Unless that won't work?

    Friday, January 27, 2017 3:51 AM

All replies

  • Hi,

    What are the symptoms of 'loses LAN connectivity'?

    Does the 'shared' vSwitch created by the wizard get the same IP as the team has?

    When created, what happens if you disable one of the NIC's in the team?

    /\


    Best Regards,

    Jesper Vindum, Denmark

    Systems Administrator

    Help the forum: Monitor(alert) your threads and vote helpful replies or mark them as answer, if it helps solving your problem.

    Friday, January 27, 2017 4:38 AM
  • Hi Silicon,

    >>I'm wondering if the problem is that my dual NICs were teamed prior to adding Hyper-V and the Virtual Switch?

    Perhaps I need to un-Team the dual NICs and then configure Teaming from w/in the Hyper-V Manager wizard?

    Your steps are correct, create nic team and then add virtual switch.

    >>when I add an external Virtual Switch using the already-teamed NIC (with Allow management OS to share this network adapter checked), the host server loses LAN connectivity.

    When the virtual switch was created, check the virtual nic on host to see if it has the correct IP settings.

    Besides, update the NIC drivers.

    Best Regards,

    Leo


    Please remember to mark the replies as answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Friday, January 27, 2017 5:24 AM
    Moderator
  • when I add an external Virtual Switch using the already-teamed NIC (with Allow management OS to share this network adapter checked), the host server loses LAN connectivity.

    Exactly what is expected to happen.  In fact, you had to click a message box telling you that it was likely going to happen.  When you create a virtual switch on a physical NIC (or team), all IP protocols are removed, which means you lose LAN connectivity.  Hyper-V then installs its own switching protocol onto the NIC.  If you have check the box to allow the management OS to share, Hyper-V creates a virtual NIC in the parent partition to be used by the parent partition.  That is where you would configure your IP settings.


    . : | : . : | : . tim

    Friday, January 27, 2017 1:46 PM
  • when I add an external Virtual Switch using the already-teamed NIC (with Allow management OS to share this network adapter checked), the host server loses LAN connectivity.

    Exactly what is expected to happen.  In fact, you had to click a message box telling you that it was likely going to happen.  When you create a virtual switch on a physical NIC (or team), all IP protocols are removed, which means you lose LAN connectivity.  Hyper-V then installs its own switching protocol onto the NIC.  If you have check the box to allow the management OS to share, Hyper-V creates a virtual NIC in the parent partition to be used by the parent partition.  That is where you would configure your IP settings.


    . : | : . : | : . tim


    It will take the IP belonging to that nic

    Best Regards,

    Jesper Vindum, Denmark

    Systems Administrator

    Help the forum: Monitor(alert) your threads and vote helpful replies or mark them as answer, if it helps solving your problem.


    Friday, January 27, 2017 1:58 PM
  • You should be attaching your Virtual Switch to the Team, not a NIC of the team.


    Brian Ehlert
    http://ITProctology.blogspot.com
    Learn. Apply. Repeat.

    Friday, January 27, 2017 3:55 PM
    Moderator
  • I bring up a cmd prompt, ping a workstation, "destination host unreachable", same response when trying to ping the server from a workstation.

    I checked ipconfig settings, all looks exactly as it was prior to creating the vswitch. I can even ping localhost including the IP4 address. But the server can't ping anything else on the network, nor can it get to the gateway router; workstations can't

    I opened networking and checked the new vswitch's settings (manually set prior to the vswitch creation because the server is a domain controller) and everything looks correct there as well. However, no internet connectivity, of course. Looking at the vswitch's properties, everything is checked exceptHyper-V Extensible Virtual Switch and Microsoft Network Adapter Multiplexor Protocol. I assume those are correct? (I didn't muck with them.)

    Saturday, January 28, 2017 12:39 AM
  • I created the nic team a long time ago, i.e. before installing Hper-V. All the documentation on the web I've seen shows creating the team from w/in the Hyper-V Manager. Is there a difference? If so, the only thing I can think of is to delete the vswitch, unteam the nics, then team the nics from w/in Hyper-V Manager.

    Perhaps a setting on the teamed nic is interfering somehow
    Team Mode: switch independent
    Load Balancing Mode: dynamic
    Standby Adapater: none (I only have the 2 physical NICs.)

    Perhaps the firewall's an issue? (I can't see how, but...)

    Saturday, January 28, 2017 12:50 AM
  • Aye, that's what I thought, and everything appears correct. If I go into Networking and view properties on the vswitch NIC, it shows all the correct IP4 settings. Like I stated in an a prior reply above, I can even ping localhost and the IP4 address, I just can't ping a workstation or vice-versa. In fact, since my server is the domain controller and has DNS and DHCP, the workstation can't even resolve the server name any more...ping resolves, of course, but nslookup doesn't.
    Saturday, January 28, 2017 12:53 AM
  • Aye, that's what I did, and everything looks correct except network traffic won't flow. When I open networking and look at the new vswitch's properties, I can see packets going out, nothing receiving, zilch.
    Saturday, January 28, 2017 12:57 AM
  • Hi Silicon,

    >>Perhaps the firewall's an issue? (I can't see how, but...)

    Disable firewall temporarily.

    When creating the virtual switch, which NIC did you select?

    If possible, post the screenshot of the virtual switch properties in hyper-v manager.

    Have you tried to update the nic driver?

    Best Regards,

    Leo


    Please remember to mark the replies as answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Monday, January 30, 2017 5:58 AM
    Moderator