I recently purchased a Dell precision 7720. With 32 GB of ram, I had enough resources to build a small VM lab. I installed 5 Virtual machines. It worked really well. I noticed a new feature as well. There is a Default Vswitch created in Hyper-V. This network gets assigned a default network and subnet. This is special because this vswitch is NAT enabled and cannot be deleted!
This turns out to be a good thing. You are able to give your Virtual machines internet connectivity to the outside world without consuming a shared External Network Adapter. It turns out this particular Vswitch is not special. You don’t even have to use it.
In fact, I outline below how to create a NAT network below, that has a subnet I am more comfortable with. Three steps is all you need. If you need to fix your “default switch”, just skip step one with the command Get-NetIPAddress | fl interfacealias,interfaceindex. Use your interface index to begin with Step 2. If you try to remove the default switch from Hyper-V, the Vswitch should reset. You can remove the switch from Device Manager, but you will still see the switch in Hyper-V. this is working as designed. I think a restart may be required to restore functionality after you remove the network.
This is step 1
- Create Internal Hyper-V network V-Switch (take note of InterfaceIndex. You need to use it in step 2)
New-VMSwitch -Switchname “myswitch” -switchtype internal -verbose
Now Step 2
- Associate IP to Vswitch to serve as gateway and IP address to adapter
New-netipaddress -ipaddress 172.24.66.145 -prefixlegnth 24 -interfaceindex 27 -verbose
Then Step 3
- Define network and subnet for NAT
New-netnat -name NatNetwork -InternalIPInterfaceAddressPrefix 172.24.66.0/24 -verbose
- Get VM connected to VM switch in step 1
Get-VM | Get-VmNetworkAdapter | Connect-VmNetworkAdapter -switchname “myswitch”
To remove the network simply run Remove -NetNat -name “Natnetwork”
Just a quick Note on steps I used to fix my box for a situation i was setting up.
I hope this helps