How To Create Stable Private Network On Hyper-V
If you find yourself stuck in a situation where you have to use Hyper-V and you hate how it doesn't come with the ability to keep the same static IP range for your private VLAN after a reboot, this gist might be for you. It shows the powershell commands to create a new private VLAN, configure it to NAT all outbound traffic, and assign the interface a static IP that doesn't change when your computer reboots. It also shows how to create and configure a very simple VM running dnsmasq that will always start at boot and handle all your DHCP needs on the private interface.
The example below uses the 172.26.48.0/22 subnet. Please be sure to update the code as needed to reflect whatever subnet you want to use.
Create Private Network
New-VMSwitch -SwitchName "internal-172.26.48.0-22" -SwitchType Internal -Verbose