Editing config file for the network interfaces in a breeze – unless you make all the necessary edits, save then quit editing, restart your networking and get utterly mortified by the horror of the fact that the interface you’ve just edited would not allow itself to be brought up to an online state again.
RTNETLINK answers: File exists
More often then not, the situation can be remedied by flushing the address associated with the interface thru command line like this:
ip addr flush dev eth0
As always make sure to issue this for the proper eth interface!