Check_mk is not a nagios/icinga fork, it's an addon that works with them. It's a host agent (like NRPE) that bundles all the local checks in a single run and su

Check_mk is not a nagios/icinga fork, it's an addon that works with them. It's a host agent (like NRPE) that bundles all the local checks in a single run and submits them on Nagios as a passive check.