Hyper-V VM's cannot access Host resources, and vice-versa

Question

I have several Hyper-V vm's running on this Win2008 R2 Server box, and up until a reboot of the host server, all the VM's were able to access shared folders on the host. Now, they can't even ping the host server.

From what I've seen, I need to setup an Internal only network through Virtual Network Manager in Hyper-V. I set this up, then tried to enable the Microsoft Virtual Network Switch Protocol option in this Internal Only NIC, but I get popups saying:

Your current selection will also disable the following features: Microsoft virtual network switch protocol

Which is absolutely stupid, considering the protocol is what I'm ticking the checkbox to Enable!

As of now, on the host, I have 2 NICs: Physical - This NIC on the host machine does have the MVNS protocol enabled Virtual Network Adapter - Created through Hyper-V Virtual Network Manager as an External type of network. Trying to enable MVNS on this NIC also produces the error above.

I've tried enabling Client for Microsoft Networks on the physical NIC for IPv6, but everytime I do that, all the VMs lose Internet connectivity and I cannot RDP into them.

Anything else I can try?

Solution

What you're saying doesn't really make sense. The "correct" way to setup networking with Hyper-V is to:

• Connect the one Physical NIC to the MVNS only, nothing else, Hyper-V will configure this for you and there's no reason to mess with it.
• Create a virtual NIC that's connected to one of the virtual switches (or virtual networks as the Hyper-V Manager calls them).

There are three types of Virtual Networks you can create:

• External: connected to the Physical NIC, the Virtual NIC on the Host, and any VMs you assign to it.
• Internal: connected to the Virual NIC on the Host and any VMs you assign it to.
• Private: connected to any VMs you assign it to and nothing else.

The Virtual NIC will always have access to the Physical NIC when configure properly.

If you just want the VMs to have access to just the Hyper-V Host, you can use an Internal. You can also use an External Network and they will have access to the Physical NIC's network.

Comments

[tony roth]

so when you look at the virtual switches you should see only 1 network and "do not let the managment network share this adapter" should be unchecked. is that what you see

[Dmitrij Kultasev]

I know that some time passed already, but did you solve that problem? :)

[ArslanW]

Chris - the correct setup you mention above is exactly how the environment is setup right now, nothing has changed. The only difference is that everything was fine before the reboot, but now communications between host and guests is not going though.

[learnningprogramming]

I would delete your existing switch and start over following Chris' advice, especially his point about not messing with things (like in your original post you mention enabling MVNS in the physical NIC, etc). Hyper-V networking is painfully simple. I think you're overthinking it and messing with stuff that you should leave alone. You might also want to read up Microsoft's site about how 3 Hyper-V networks work and how they are implemented - it is really straightforward and doesn't require you futzing with details.