For years it’s been simple to set up DNS on a Linux machine. Just add a couple of entries to /etc/resolv.conf and you’re done.
# Use Google's public DNS servers. nameserver 18.104.22.168 nameserver 22.214.171.124 But things change and now it’s not that simple. If you now edit /etc/resolv.conf on Ubuntu you’ll find that the edits are ephemeral. If you restart (or even hibernate) your machine then they’ll be overwritten by default content.