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While setting up nrpe monitoring on a new dev machine, I've run into a bit of a snag. I've followed all of the recommend steps I could find, and still to no avail.

Executing /usr/lib/nagios/plugins/check_nrpe -H localhost -n results in a socket timeout, regardless of the the time specified with -t.

netstat -latnp | grep 5666 results in:

tcp        0      0  *               LISTEN      26718/nrpe  

I'm using 12.04 LTS. Any thoughts would be appreciated.

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Does the same happen when you substitute localhost with – zhenech Mar 10 '14 at 21:13
Why are you disabling SSL? – Keith Mar 11 '14 at 14:11
I flushed the iptables to see if this was at all an issue. /usr/lib/nagios/plugins/check_nrpe -H localhost returns version of NRPE as expected. However, still having an SSL error when trying connection to remote monitoring machine. Trying the same check from the monitoring machine works as expected, returning the version of nrpe running on the client. I have the same setup configuration-wise on a production machine, and I am able to run all of my monitoring checks that rely on nrpe just fine. – dprog Mar 11 '14 at 15:18
the SSL-ness of each end has to match. That is, if you compile NRPE with SSL, check_nrpe has to use SSL. If you don't, you have to use -n. Using packaged versions should eliminate this inconsistency though. – Keith Mar 13 '14 at 14:58


# /usr/lib64/nagios/plugins/check_nrpe -H localhost 
NRPE v2.14
# /usr/lib64/nagios/plugins/check_nrpe -H localhost -n
CHECK_NRPE: Error receiving data from daemon.


# grep -E 'nrpe.*Error' /var/log/all.log | tail -1
Mar 11 12:08:00 XXXXX nrpe[4941]: Error: Could not complete SSL handshake. 1

I'm not sure why it's complaining about -n could be something related to SSL, however it's not recommended way anyway.

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