Ubuntu changed networking. Embrace the YAML.
If I'm being completely honest, I still dislike the switch from
eth1, eth2 to names like,
enp3s0, enp4s0, enp5s0. I've learned to accept
it and mutter to myself while I type in unfamiliar interface names. Then I
installed the new LTS version of Ubuntu and typed
/etc/network/interfaces. Yikes. After a technological lifetime of entering
my server's IP information in a simple text file, that's no longer how
things are done. Sigh. The good news is that while figuring out Netplan for
both desktop and server environments, I fixed a nagging DNS issue I've had
for years (more on that later).