I have a Virtualbox VM which, over time, has been opened on 9 different host operating systems. I reinstall my main OS move than the average person without a doubt. Every time the guest VM is opened from a new host, it adds a new device. So I ended up with 9 ethernet devices. Every time I opened the VM on a new machine I’d also have to reconfigure my static IP. Removing these devices isn’t as difficult as you may think. It’s simply a matter of editing the /etc/udev/rules.d/??-persistent-net.rules file and committing out all the lines that begin with SUBSYSTEM. Then reboot and you should have a fresh eth0.