Dear Maintainer,
After reconfiguring 1 network interface to a new range, but forgetting to remove the last line, then one with 192.168.123.9 from /etc/nut/upsd.conf
LISTEN 127.0.0.1 3493
LISTEN 192.168.119.253 3493
LISTEN 192.168.123.9 3493
The nut daemon refused to run after it at a later date was restarted. Syslog just reported:
Apr 2 20:54:11 dkfitlet upsd[16941]: Network UPS Tools upsd 2.7.4
Apr 2 20:54:11 dkfitlet upsd[16941]: not listening on 192.168.123.9 port 3493
Apr 2 20:54:11 dkfitlet upsd[16941]: listening on 192.168.119.253 port 3493
Apr 2 20:54:11 dkfitlet upsd[16941]: listening on 127.0.0.1 port 3493
Apr 2 20:54:11 dkfitlet upsd[16941]: no listening interface available
Notice the last line message: "no listening interface available" which is not true, as 2 out of 3 configured LISTEN addresses was available. Notice also that syslog does not say that upsd exitted.
After removing the bad line from upsd.conf "LISTEN 192.168.123.9 3493" everything started working fine.
I would expect that upsd listens to the addresses it can find and not just exit.