[systemd-devel] resolved: disabling automatic resolution of hostname and IP?

[Lennart Poettering]

On Do, 09.09.21 18:16, François Cami (fcami at redhat.com) wrote:

> Hi,
>
> Is there a way via the resolved configuration file to disable the automatic
> resolution of the hostname and the IP of the host?

There is no way to do this globally or for the DNS stub,
currently. You could parse the upstream DNS servers from
/run/systemd/resolve/resolv.conf and query those DNS servers
directly. That file always contains a valid resolv.conf with all known
upstream DNS servers and is updated instantly when DNS config changes.

You could also explicitly resolve via resolved (either via D-Bus, or
varlink), where in very recent versions you can set a flag to disable
such "synthetic" RRs. This is also exposed via "resolvectl query
--synthesize=no …".

> The reverse DNS resolution like:
>
> # dig +short -x 192.168.115.40
> ipa0.ipa.test
> ipa0.
> ipa0.local.
>
> is problematic when FreeIPA needs to detect whether the IP of the host
> already belongs to a reverse zone. I'd expect NXDOMAIN there instead.
>
> Any input will be much appreciated.
>
> Thank you,
> François
>
>

Lennart

--
Lennart Poettering, Berlin