v5 how to block Internet?

Hi I am testing some software in a Virtual Machine and every time it starts up it needs to check home (I am writing the software) and I need to see how it handles no Internet.

If I set “Block All” then the VM will not run as it needs the network to load the VM-Guest.

At the moment I am pulling the RJ-45 (DSL-Modem) plug after the VM looks like it is underway but sometimes it works and sometimes it does not so I need to be able to just block all Internet.

Thanks