[Nut-upsuser] Poll UPS / Driver not connected with UPS MGE Evolution 850VA USB

Charles Lepple clepple at gmail.com
Mon Mar 2 22:10:30 UTC 2009

On Mon, Mar 2, 2009 at 4:47 PM, Vianney Lejeune <via.lej at free.fr> wrote:
> Thank you it works very well. By the way, I noticed something weird. nut is
> configured to listen only on localhost:
> ACL all
> ACL localhost
> ACCEPT localhost
> REJECT all
> But nut keeps listening on the TCP 3493 port. Is it normal ?

upsd will always listen on at least one TCP port. The
ACCEPT/REJECT-style ACLs (which, by the way, are deprecated in favor
of the more standard tcp-wrappers library) only affect how connections
are handled once clients are accepted.

If you only want NUT to listen on the loopback network interface, you
need to use "LISTEN", which is not available in 2.0.5. In
any event, binding to an interface with LISTEN, or using your OS
firewall facilities, will filter packets at a much lower level than an
application-layer ACCEPT/REJECT or a tcp-wrapper ACL.

- Charles Lepple

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