A lot of people coming to NSClient++ has a background in NRPE since it is a common transport mechanism for check results on Linux.

And while NSClient++ is fully NRPE compatible it allows for more control and has more features which can make it seem difficult to get started with. This is a guide for getting started with NSClient++ from a NRPE perspective.

The biggest reason for Nagios success is the ability to extend it with custom scripts which makes it one of the most powerful monitoring systems. Now Nagios is not the only place where you can extend your monitoring! NSClient++ provides many ways to extend it with scripts and since I have gotten many questions about how to use scripts with NSClient++ lately I have decided to write this tutorial to help sort out the concepts.

NSClient++ despite its name is most often used in server mode responding to remote calls via either NRPE or check_nt. The closest thing to a client we get in normal mode of operation is NSCA where we submit data back. But NSClient++ can act as a client as well which is not just something I use for unit testing but something which can actually be useful in your monitoring environment.