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mnemosyn
Asked: 2010-05-11 02:50:09 +0800 CST

"No active network adapters found" Hyper-V 2008 R2

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I fiddled around with the virtual network settings of my Hyper-V server, because Windows Update failed to run in the VMs. I set the flag that makes the NIC exclusively usable by the VM. Now, the host system tells me it has no active network adapters.

What does that even mean? According to netsh, there are three enabled network connections. I tried to restart the NICs using devcon.exe (the correct x64 version), but that doesn't make any difference - still, devcon reports the NICs are there and they are activated?!

Is there any way I can force the host (using the console) to re-enable the NICs?

hyper-v-server-2008-r2

4 Answers

  1. I locked myself out of the server by making the nic exclusively usable by the VM. To make the NIC also usable by the management OS you can use the following in PowerShell:

    Set-VMSwitch -Name "YourName" -AllowManagementOS 1

    If you do not know the names of your virtual switches, you can use:

    Get-VMSwitch
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  2. Since you already solved the problem by rebuilding this isn't helpful to solve it - but for future problems, most of Hyper-V is manageable through WMI and you could have solved the problem that way.

    Rather than getting into the details of that though, I will link you to the Powershell Management Library for Hyper-V, which is a sweet Powershell based wrapper around the WMI calls. You could have used it to remove the NIC from the VM and that should have given you your access back. Get it installed now before you have future problems...

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  3. This error can occur if you uncheck, "Allow management operation system to share this network adapter" from within 5Nine Manger. Get local console to the HyperV server and run the following powershell commands. Change "External" to match your switch name.

    GET-VM | GET-VMNetworkAdapter | Connect-VMNetworkAdapter –Switchname "External"
Set-VMSwitch -Name "External" -AllowManagementOS 1
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  4. Best Answer

    Undo your change.

    I set the flag that makes the NIC exclusively usable by the VM

    Logically - if the NIC is reserved exclusively for the VM, obviously the host can not use them anymore.

    Open the settings for the Hyper-V networks you created. you can turn them on there for the host, too (so that the host and the VM's can use them).

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