I have had NSclient++ working with Nagios for a while now. Recently I started testing Nagwin just to see how it would work, out of pure curiosity. I stopped checking a test server with my main Nagios config, set NSclient++ to NRPE mode, and pointed Nagwin at it. It worked great for a few hours then suddenly I started seeing "UNKNOWN: No Handler for that command." I figured it has to be Nagwin's fault since it's so new, I'll just unload NRPElistner.dll and return my server to being monitored by check_NT. However now check_NT doesn't work my main Nagios server returns timeout errors and is unable to connect at all. My Nagwin server can connect to it, the server just doesn't know how to handle the check_NRPE commands even though it did with no changes a few hours earlier.
I have been working on this for a day now and am fairly certain it is NSclient++ who is to blame here. My nagwin box has successfully stayed connected to a similar server throughout the night, without any issues. And my main Nagios config is not having any problems at all. I have been able to successfully switch another server between being monitored by nagios and nagwin without any problems by simply loading and unloading the NRPE.dll. I have tried uninstalling NSclient++ and reinstalling with fresh configuration but still receive the errors. As of now the firewall is off on the server, NSclient++ is setup to accept connection from any server, there is no password, I have also turned ssl off, and the NRPE module is loaded. Any Ideas would be appreciated, I am not an advanced Nagios user but I do know my way around it and can easily break it down and set it up again.
I also want to add that while in test mode NSclient++ is unable to handle check_NRPE commands there either.