[systemd-devel] systemd.network vs. ifupdown vs. netplan?

[Ansgar]

John Ioannidis writes:
> Is there a document somewhere that details what the
> interactions/conflicts/etc are between systemd.{link,netdev,network} and
> the ifupdown mechanisms? I have read the manual pages, of course, but I
> feel I'm missing something fundamental. I finally got around to moving to
> Debian 10, and in the process modernizing some of my configurations.

I don't think there are any interactions between systemd-networkd and
Debian's ifupdown mechanism.  They are just alternatives you can use to
configure network interfaces; there are other alternatives like
NetworkManager.

You can also use them in parallel as long as only one system manages a
given interface.  I find that mostly useful to have VPN connections in
NetworkManager which has nicer desktop integration.

> Then there is netplan, which Canonical is pushing with Ubuntu; it does not
> have feature parity with ifupdown, so it is not under consideration right
> now, but if the comparison includes that, so much the better.

As far as I understand Canonical's netplan.io is an abstraction layer
that allows choosing between systemd-networkd and NetworkManager to
manage interfaces (maybe also others?).  Personally I would just use
either system directly.

Ansgar