DNS Tools
[ 1 Resolv.conf ] [ 2 Monitoring ]
Resolv.conf
Confguration is updated by various programs in /etc/resolv.conf
. This is managed by systemd-resolved
and will get cached & overwritten when pursuing activities like vpn.
Monitoring
One problem-to-solve is ‘Who has last written to that file?’
# The following command lists the most recent activity and monitors (-f, follow) it for incoming activity
$ sudo journalctl -u systemd-resolved -f
To get additional verbosity (debug) information on the channel, you’ll need to reconfigure and restart the resolved
daemon:
[Service]
Environment=SYSTEMD_LOG_LEVEL=debug
into the override.conf
of systemd-resolved
via
sudo systemctl edit systemd-resolved
Restart to take effect:
See also: unix.stackexchange:how-to-troubleshoot-dns-with-systemd-resolved.