I am on Precise. I used this command (with an alias), to close the network, dbus-send --system --print-reply --reply-timeout=120000 --type=method_call --dest=org.freedesktop.NetworkManager /org/freedesktop/NetworkManager org.freedesktop.NetworkManager stop it worked, now I have to use dbus-send --system --print-reply --reply-timeout=120000 --type=method_call --dest=org.freedesktop.NetworkManager /org/freedesktop/NetworkManager org.freedesktop.NetworkManager.Sleep boolean:true it work but not so well, sometimes I can't restart the network and NetworkManager is blocked too and strange errors even GUI freeze . What I need is a command line which close the network and don't mess with Network Manager, maybe with the routing table or what else.