802.1xhyper-vnetworkingvirtual machine
We are using 802.1x authentication inside the corporate network. When I installed HyperV Virtual Switch on my machine to let the VM into the network, the host lost its network connectivity.
I came upon a post on an MS support forum that 802.1x with Hyper-V is officially not supported by Windows 8.1. Apparently, the same problem exists on Windows 10.
How can one use Hyper-V VM and have connectivity for both host and VM in case of 802.1x authentication policy in the network?
Well, I figured it out. I had to create an Internal Virtual Switch and then go to the External Virtual switch and share its connection with the Internal Virtual Switch.
So you have . . .
The VM Mikrotik machine configured with two NIC's with one connected to the "internal" Hyper-V switch (inside) that has the DHCP service running on it, and the other is connected to an "external" Hyper-V switch (outside), etc.
The lUbuntu VM has one NIC and you connect that to the "internal" Hyper-V switch which has a DHCP server service listening on it from the Mikrotik machine to process requests accordingly.
1. Configuring VM Networking on a Hyper-V NAT Switch
Virtual machines that are connected to a NAT virtual switch are in an isolated broadcast domain, a different one to the LAN. The NAT switch does not have flat, 2-way routing to the LAN that the host is connected to. The virtual switch is an internal virtual switch that the host NATs to the LAN. This means that, by default, the virtual machines can connect to the LAN, but the LAN cannot connect to the virtual machines. And even if we do create NAT rules, the virtual switch remains a separate broadcast domain from the LAN.
The virtual switch is somewhat isolated from the LAN, especially from broadcast-based services such as DHCP. You can deploy your own DHCP server(s) as virtual machines that are connected to the virtual switch. The scope of these servers is limited to the virtual switch, so there is no impact on the LAN, and network administrators should not have a problem with your DHCP servers being deployed on the NAT virtual switch.
2. Internal Hyper-V switch configuration
Internal: Allows communication between virtual machines on the same Hyper-V server, and between the virtual machines and the management host operating system.
3. Visualization of all switch modes
The way I've handled this is to ensure the VMs connected to the internal switch have IP addresses assigned, and then from the host Hyper-V management server, I then can access those machines from the host OS that way via their IP addresses.
You could probably look over the Set up a NAT network, and be sure to have a full understanding of it and then Create a NAT virtual network and configure it accordingly to see if it'll do what you want using the "internal" Hyper-V switch functionality.
Since the VMs can talk with the Mikrotik machine, perhaps you can setup routing in it and then tell the VMs to use it's accessible internal Hyper-V switch IP address as the default gateway on all those devices, and just let it do the routing when things need accessed that's not connected to the internal Hyper-V switch.
Check your VLAN configuration and see Configure virtual local area networks for Hyper-V in the event something at this level is needed or causing trouble.
Check any OS level firewall rules for the blocking of the traffic coming from the internal Hyper-V switch to the host Hyper-V or any of the connected VMs.
Best Answer
According to Jeff Woolsey on windowsserver.uservoice.com, 802.1x support has been added:
Further write-up by Didier Van Hoye on WorkingHardInIt.work blog.