Dual monitors using a laptop as a second display. This guide assumes that you are using a Debian based distro (X11 only). Both devices must be connected to the same network. 1. Define an output to be a used as a dummy monitor a. The simple method: select an unused existing graphics port # find an unused output find -L /sys/class/drm -maxdepth 1 -type d -name 'card0-*' -exec sh -c 'if [ $(cat $0/