man mDNSResponder
suggests that sudo killall -USR1 mDNSResponder
will enable warning and notice logging, and that sudo syslog -c mDNSResponder -d
will enable log levels Emergency to Debug. Additionally sudo killall -INFO mDNSResponder
should dump current state to /var/log/system.log
.
None of these have any effect on macOS Sierra. None of the commands fail, but they don't actually log anything in /var/log/system.log
either.
Best Answer
In my opinion parts of the log system of macOS 10.12.0 are flawed.
The output (dump) of
sudo killall -INFO mDNSResponder
is visible in the Devices > $hostname "log" though.First launch Console and choose your host device in the left pane. Enter a filter like mDNS in the search field at the top.
Then enter
sudo killall -INFO mDNSResponder
in Terminal and watch the results fly past in Console.