KVM is Kernel-based Virtual Machine. It's a module built directly into the Linux kernel that allows the operating system to act as a hypervisor. Although some people may prefer a third-party solution like VirtualBox, there's no need to install extra software since the Linux kernel already gives us the necessary tools we need to make virtual machines.
Followed the instructions to create the /etc/network/interfaces file and after rebooting had no network at all. Renamed the file, rebooted again and my network came back. Continued with the instructions and everything works fine. My VMs have full Internet connectivity and work great.
YMMV but this step was not needed for me and despite the statement “Doing this won’t negatively impact your connection at all.” it did just that to me.
This is an half cooked guide, useful just if you already know how to do this. the suggestion would be not to publish a guide at all if you have to leave people WHO ARE NOT SUPPOSED TO KNOW THE TOPIC ALREADY out in the cold. The part on the network setup of a bridge interface, for example, is atrocious, it makes your current network interface way stop working and the bridge interface is never used in the rest of the “guide”. Let’s use this as an example on how NOT to write a guide at all if one does not have the stamina to do it the proper way.
After configuring /etc/network/interface and rebooting - no internet connection - checking other pages this seems to be doing more than is necessary and actually not working.