I recently had my computer crash hard while my bitnami Ruby on Rails stack was running in VirtualBox. When I tried to start up the virtual machine again it said "waiting for network configuration" and hung for about a minute. Then it said "Continuing to wait for network configuration for another 60 seconds." Once the system started I noticed it didn't have a ip address assigned and if I typed ifconfig I only got the loopback interface (no network interface to speak of). Luckily, there was a simple fix for this, but it took me a little while to figure out so I figured I'd share it here in hopes others with the same problem will wind up here and I can save you some time.