I am making a virtual network setup for my high school cybersecurity team to practice. I am connecting all the VMs together through a VPN and then people who are practicing will VPN in and ssh/remote desktop into the different VMs. The problem is that for practicing, they will need root access into the VMs and because the VMs are connecting to my personal network, the VMs pose a security risk to my personal network. Is there any way in either VMWare or VirtualBox or even making an unchangeable iptable (I can make all the windows VMs go thru a linux VM) to prevent people from connecting to my local network via the VM?