If you get the following error (“CHECK_NRPE: Error – Could not complete SSL handshake.“) when trying to connect to a remote NRPE (nagios) setup you should check on the NRPE machine that check_nrpe client IP is in the list.

ie. allowed_hosts=127.0.0.1,YOUR_OTHER_IP

In the /etc/nagios/nrpe.cfg configuration file.

CHECK_NRPE: Error - Could not complete SSL handshake.