Sometimes, if the Vagrant machine does not start and shows the message ” Error: Connection timeout. Retrying…”
vboxmanage list runningvms # get the machine name (eg: project_default_1425638498633_14295) and run # this will send an "Enter" to the machine in case is stuck in boot screen vboxmanage controlvm project_default_1425638498633_14295 keyboardputscancode 1c