Once configured NSClient++ in windows server if you have received an error, could not fetch information from the server.

Assume that, If you have installed MRTG for monitoring network device on Linux system, also you would like to monitoring MRTG on Nagios.

You may get encounter error “CHECK_NRPE: Error - Could not complete SSL handshake” from Nagios monitoring you need to check SSL or nrpe file configuration

You may get CRITICAL error "Connection refused by host" on Nagios monitoring tool after installed and configured Nagios in client system.