When playing around with Virtual Box guests running Linux, the network connection my get lost on Debian Etch when the virtual interface's MAC changes. This is due to the fact that this version of linux is using udev and fortunately udev detects changes to MAC address. So basically, each new network interface with new MAC address gets its new ethx network interface device name. In my case, I got 3 ethx's already so I need to get rid of the unnecessary interfaces. As a root do this: $: su #: cd /etc/udev/rules.d #: mkdir ~/bak #: cp zxx_persistent-net-generator.rules ~/bak #: rm zxx_persistent-net-generator.rules #: /etc/init.d/udev stop #: /etc/init.d/udev start Note that we make a backup of the file just in case we need to go back. Also, for zxx_persistent-net-generator.rules, xx is any two digit number. So just go check the directory for a file that resembels *_persistent-net-generator.rules. Now to prevent udev to generate new interface for every new MAC address for Virtu