In my case(my machine is ubuntu 16), I append /etc/resolvconf/resolv.conf.d/base
file by adding below ns lines.
nameserver 8.8.8.8
nameserver 4.2.2.1
nameserver 2001:4860:4860::8844
nameserver 2001:4860:4860::8888
then run the update script,
resolvconf -u