I have a frustrating issue: I have a Win10 system running Hyper-v with a single Ubuntu VM.

I set it up and it ran for several days perfectly connected to the network, network browsable by other network devices and host programs operating as expected. Thus was Ubuntu 18.xx and my first move into both Hyper-v and Ubuntu. I have broad, but somewhat rusty skills in networking, host/server and programming skills. I figured, “piece of cake!”

Two days in, I allowed Ubuntu to upgrade to 20.xx and needed to reboot the Win 10 machine. When it all came back, the Hyper-V VM running Ubuntu is now its own DHCP and DNS server thus no longer on my network as even the net mask is different. WHAT THE HELL HAPPENED?

Thanks bud.

Correct.

For this to be possible we need to create the virtual switch where connection type is external correct?

The second and all further virtual network adapters for the management OS must be added via PowerShell. Check the how-to links at the end. You can also use Windows Admin Center.

This is a great article. Question though. If you have 2 10Gb NIC’s teamed in the OS and set as the uplinks into a virtual switch as you show in the last example, where do your vNIC’s come from for live migration, etc? We can share the team with the OS and get one virtual NIC in one VLAN, but how do we create more for things like LiveMig? We’re not clustered, but we do want to take advantage of the 10Gb links for replication, moving shutdown vm’s between hosts, etc. Your last example seems to show this, but I’m lost on the vNIC’s after the mgmt one… Thanks!

I think you stopped reading far too early. Hyper-V VMs can perform off-host communications.

Thank you!

I have never seen a VM lose its VLAN due to a Live Migration. I would revisit that testing because having multiple virtual switches is hurting your build.

So I was using the multiple vSwitches with one per VLAN. so that I could transfer between hosts without problems. I can’t remember if that was before I had made identical Virtual Switches on the multiple hosts, or not, though.

Have you seen anything like that?

I recommend that you look through the links at the end of the article. They provide much more how-to and cover the possibilities.
You’ll probably want this one: https://www.altaro.com/hyper-v/complete-guide-hyper-v-networking/. The parts about adding virtual NICs is roughly halfway down for PowerShell. The GUI instructions start up a bit after that.
Once you have a vNIC created for the management OS, it shows up like a regular physical adapter and you assign IP information as normal.