[systemd-devel] F30->F31 systemd-networkd no IPv6 autoconfiguration

[Anthony Joseph Messina]

On Saturday, November 9, 2019 1:49:04 PM CST Thomas Haller wrote:
> On Fri, 2019-11-08 at 20:30 -0600, Anthony Joseph Messina wrote:
> > Thank you for responding Ryan.  AFAIK, I don't have both systemd-
> > networkd and
> > NetworkManager "running" or enabled. In fact, I have had
> > NetworkManager
> > disabled on these systems for some time (back through F27, I
> > believe).  Post
> > upgrade (or fresh install) I ensure that NetworkManager is not re-
> > enabled, and
> > that systemd-networkd is enabled.
> > 
> > 
> > 
> > Unforuntately, trying to remove
> > NetworkManager completely seems like a heavy hammer based on the `dnf
> > remove`
> > output below.
> 
> Seems dnf wants to also unstall packages that were installed due to
> NetworkManager. For exapmle, "libndp" obvoiusly has no dependency on
> NetworkManager (but the other way around). You probable should use the
> right argument to dnf to not remove unrelated packages.

Thanks again Thomas.

After `rpm -evh --nodeps NetworkManager` and `dracut -fv` followed by a reboot, systemd-networkd properly sets the IPv6LL and works with IPv6 autoconfiguration.

> > Also, these identical systemd-networkd configurations do work on F30,
> > just not
> > on systems upgraded to F31.
> > 
> > The only recent change I notice in F31, is that NetworkManager is
> > initialized
> > during early boot even when the service is disabled and masked.
> 
> NM indeed may now run in early boot. That has no relation to whether
> you enable the systemd service ("enabling" a service in systemd anyway
> only means to hook it up accroding to the [Install] section, and that
> does not cover what runs in initrd).
> 
> I would suspect that NetworkManager sets the interface to disable ipv6
> address generation (e.g. `ip -d link` would report "addrgenmode none").
> It probably shouldn't do so, if there is not configuration for the
> device. This is probably a bug.
> 
> Another question is what causes NM to run in initrd in the first place.
> Usually that would be caused by setting "rd.neednet=1" on the kernel
> command line. But dracut may also artificially add such a command line,
> according to its configuration. You probably don't want to setup
> networking in initrd in the first place. That is, check your dracut
> configuration...