For example if you have 2 network cards.
NIC #1 = Host Network/Management Network
- Give this a static IP address which will be the hosts primary IP and what you will use to connect using remote desktop and so on.
NIC #2 = VM Network, used only for virtual machine traffic:
- Setup in the way i explain above
- Do not set a static IP on this interface
- After you have created a Virtual Switch in Hyper-v bound to this adapter look under Network Connections on the host, right click the adapter and select properties. You will notice that the only box checked is Hyper-V Extensible Virtual Switch. TCP/IP and the rest are unchecked - This is how it is meant to be. No IP will be set on this interface.
Now the only thing you have to remember to do when creating a VM which will have direct WAN access is to make sure it's connected to the virtual switch you created which is in turn bound to the 2nd Network card attached to the WAN.
Now forget about the host. Forget about the host network cards. You will setup every new VM as if it was a physical machine. As long as it's connected to the WAN network switch you can give the guest any of your WAN IPs and it will have connectivity.