I teach an after-school program where we're using MIT App Inventor, which requires a connection between the mobile device and laptop. The network at the facility uses isolation, which prevents devices from communicating with each other.
My idea was to set up a basic VPN server that the devices could connect to and then communicate on virtual LAN. I thought I might just spin up a cloud Linux server, but obviously I can't allow connected VPN clients to access anything outside of the server.
Is there a way to create a "virtual LAN" on the server with its own set of 192.168.0.* addresses, but are "jailed" to the sever (and of course still be able to access the internet)?
You can create a private network that only your VPN server has access to. OpenVPN will create a TUN or TAP interface, and you can configure whatever address range you'd like for that interface to use. There is also a setting in OpenVPN that allows clients to communicate with one another.
However, I agree with EEAA that this is likely to become very messy very quickly, and I'd recommend trying to overcome the issues on the local network first.