On Fri, Sep 01, 2023 at 04:16:46PM -0600, D. R. Evans wrote: > Greg Wooledge wrote on 9/1/23 15:38: > > > In particular, when using /etc/network/interfaces, only interfaces that > > are marked as "auto" need to be up, to satisfy this criterion. An > > I don't think that debian has used used /etc/network/interfaces for a while, > at least not by default. Certainly there's nothing useful there on the > machine that I just upgraded and whose networking is failing to configure > itself correctly. > > Network Manager -- I think -- uses some completely different mechanism for > managing networking (although I have no idea what that mechanism is.)
Debian *absolutely* uses /etc/network/interfaces. By default, in a Standard installation. But as you noted, it's optional. Debian *also* allows the use of Network Manager, systemd-networkd, and probably several other systems for configuring one's network(s). I haven't installed Debian 12 yet (upgraded to it, but haven't installed it), but I did a Debian 11 install yesterday. And I can assure you, that system uses /etc/network/interfaces just like every other Debian system I've ever run. I used a Standard install, then booted it to confirm that all the necessary firmware was present, and then installed KDE (among other things). I don't know whether N-M is installed on that system -- I didn't check -- but it doesn't matter, because the machine's sole ethernet interface is configured in /e/n/i and therefore N-M would skip it. Returning to the previous topic, I have no idea how After=network-online.target interacts with N-M. I have experience with network-online.target vs. /e/n/i and its absurd "allow-hotplug" default setting, but I don't use N-M so I don't know how that works.
