[Nut-upsuser] NUT unable to resolve host despite DNS working.

[Roger Price]

On Sat, 17 Sep 2016, Yevgeniy Kuksenko wrote:

> Hello all, I have been having a problem with upsmon on Fedora 24 on boot. NUT is configured as a netclient to a Raspbian NUT server. After boot up upsmon
> repeatedly says "connect failed: No such host". It is not able to connect at all until the service is bounced. This seems to indicate a name resolution
> problem but shouldn't this auto correct once name resolution is working properly regardless? upsmon on the Raspbian NUT server works fine and is attached
> to localhost:3493.
> 
> If I use an ip instead of a DNS name this config works correctly on boot.

Do commands on the client such as:

  echo "GET VAR ups01 battery.charge" | netcat ups.server.lan 3493
  echo "GET VAR ups01 battery.charge" | netcat 11.22.33.44 3493

reproduce the problem?  If so, the problem may be with the DNS rather than 
NUT.  What does command dig ups.server.lan on the client report?

Roger