Forces the route to be associated with the specified device, as the
kernel will otherwise try to determine the device on its own (by
checking already existing routes and device specifications, and where
the route is added to). In most normal networks you won't need this.
is the last option on the command line, the word
may be omitted, as it's the default. Otherwise the order of the route
modifiers (metric - netmask - gw - dev) doesn't matter.