Jul 12

Windows 10: Internal Virtual Switch with NAT

Reading time: 2 – 4 minutes

When you are playing with Windows Hyper-V and you want to create a completely virtual internal network with private virtual machines inside your Windows 10 machine virtual switch are mandatory.

Then it’s the time to connect that virtual switch with the host machine using a virtual network interface. All those steps can be done using Hyper-V manager user interface, but you cannot control 100% of parameters like enable, or not, the NAT of the virtual internal network.

Using PowerShell the steps are:

New-VMSwitch -SwitchName NATSwitch -SwitchType Internal
New-NetIPAddress -IPAddress 10.46.1.1 -PrefixLength 24 -InterfaceAlias "vEthernet (NATSwitch)"
New-NetNAT -Name NATNetwork -InternalIPInterfaceAddressPrefix 10.46.1.0/24

Of course, change “NATSwitch” for your switch name and “10.46.1.1” for the IP address of the host virtual network card. Finally “NATNetwork” is another arbitrary name for referring to the NAT rule, and “10.46.1.0/24” is the network address of the virtual internal host network.

Running the commands looks like:

For removing what you did:

Remove-VMSwitch -Name "NATSwitch"
Remove-NetIPAddress -InterfaceAlias "vEthernet (NATSwitch)"
Remove-NetNAT -Name NATNetwork

In Windows 10 IP forwarding is not enabled and packets between interfaces are not routed. According to the Microsoft forums, you can enable IP forwarding (routing) using the following steps:

Go to Start and search on cmd or command. Right click on either cmd or command then select Run as administrator. At the command prompt type regedit. Navigate to the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\ Services\Tcpip\Parameters\IPEnableRouter setting, right click and select Modify. Change 0 to 1 and exit the editor.

When your back at the command prompt type services.msc and navigate to the Routing and Remote Access service. Right click and select Properties. Change to Automatic and click on Start to start the service.

I had to research a long time until I found all this information, but in my case leverage my proofs of concepts to another level.

Jan 19

DHCP server for Windows 10

Reading time: 1 – 2 minutes

This is a super useful and simple tool, first of all, let me say thanks to Dani because I found the tool thanks to him. Very often I have the requirement to set up small virtual, real or hybrid networks using my laptop as a server and I had to boot a VM for getting a DHCP server simple to manage and powerful. Now, this is not required anymore because thanks to this tool I found a super small and flexible tool, I can set up all that I need using an INI file or just a wizard. It’s a pleasure and I don’t have to install anything if I don’t want, just a tray icon application is running for allowing me to give the service to my experimental networks.

Those projects that gain my commitment in a second: DHCP Server for Windows