Tomas Krizek <tomas.krizek(a)nic.cz>cz>, 2019-03-18 11:35:17 (+0100):
`systemctl mask kresd.socket` is the correct approach.
I tested this
with a clean installation of Knot Resolver 3.2.1 and the service works
as expected (it is in 'active' state, not 'degraded').
I'd suggest to remove any drop-ins to restore the service and sockets to
its pristine state, do `systemctl daemon-reload` and try masking the
kresd.socket again. If you're still able to reproduce the degraded
state, please tell us which OS distribution you use and its systemd
version to debug this further.
Thanks, and I would have found out about masking had I read kresd.systemd
more carefully than I did.
I had to do `systemctl reset-failed kresd.socket` to get back to `running`
state.