Oddly, none of those options are in a Sandbox, and require an actual Azure subscription for learners, like some other segments. Ah well, let's briefly talk about Azure VPNs.
Azure VNs provide the same network capabilities as regular VNs, or even VLANs that are spread out physically, and you may need to jump onto Layer 3 to access your virtual neighbor in another cubicle.
- Internet communications
- Route and Filter Network Traffic
My guess is that you go to the Dashboard, see the list on the left, hit Virtual Machines and poke around for an option to turn it off.
Or, you could make an Access Control List and set it to deny all for incoming traffic.
Or set it to a private IPv4 address that can't be routed over the internet.
When you create a virtual network, remember to consider the location of the users and the machine hosting it.
When you've made them all, go to the Virtual Networks tab and connect them together.
You can even do it in Powershell first by making the network and then making the machines and delegating the network they should be within.
Gosh, that is so much easier that fiddling around in the VirtualBox settings. What a time to be alive.