Nested Hyper-V under VMWare Esxi 6 U2 Guest Internet Access

Recently we started working with a small client that had a HP ML30 server installed by their previous IT provider. The OS, Win 2019 Essentials, was installed on the physical hardware rather than under a hypervisor like VMWare or Hyper-V.

We wanted to install a few CentOS virtual machines with some unusual configurations, so we decided to run a test environment here in our office before rolling it out to the client. We run VMWare Esxi 6 U2 here, so decided to download the trial version of Win 2019 Essentials and install it as a guest under Esxi.

So what is the problem? Because we wanted to nest a Hyper-V hypervisor under VMWare there are a number of issues that you need to address to ensure it runs and we've documented those here so you don't have to waste the time we did researching the issue. The main problem being that the CentOS VM, or any VM for that matter, that was installed within the nested Hyper-V instance could not access the internet.

To outlined the setup again, we have:

  1. VMWare Esxi 6 U2 as the host
  2. Win 2019 Essentials as the guest
  3. Win 2019 guest will have a nested Hyper-V instance configured

Lets start...

Create your Win 2019 virtual machine with your preferred settings but do not start the machine because we have some additional configuration to do. We're using the vSphere client here in this example, but you can use the Web UI is you wish as well. Once your VM is created, edit the machine's settings and follow the screenshot below:

We're now going to edit the virtual machine's vmx file and add a few entries to ensure it allows a hosted hypervisor. Download the vmx file onto your computer and edit it with notepad or your favourite text editor and add the following 2 lines at the end of the file:

hypervisor.cpuid.v0 = "FALSE"
vhv.enable= "TRUE"

Save the file and upload and overwrite your existing vmx file in your VMWare machine.

Now we need to change the Promiscuous Mode on the vSwitch that your machine is connected to. From your vSphere Client go to Configuration > Networking and click on the Properties link associated with the vSwitch your VM is connected to. In my case it was vSwitch0, but yours may be different. Now follow the screenshots below:

Now you can can start your Win 2019 Essentials VM and you will be able to install the Hyper-V role and have internet connectivity for the the guest OS instance your install on your Hyper-V nested hypervisor.

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2 Responses

  1. Thank you so much! I have ESXi hosting a Windows Server 2019 VM. The latter VM has the Hyper-V role which is hosting a Windows 10 guest VM. Enabling the 'CPU virtualisation exposure' option on the HyperV server was something I was aware of. However, the nested networking was a concern. Microsoft recommend enabling MAC address spoofing on the HyperV guest OS, so I did so on the Win10 VM. However, still no network connectivity. It was only after days of troubleshooting that I can across your blog post recommending ESXi host network security configuration to enable promiscuous mode, etc. I tried this and voila! my troubles solved! Thank you again for sharing as this makes life easier for IT support folks.
    • Matrix7
      It took me ages to get this to work as well, so I'm glad it's helped someone else out...

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