Sending passive check results for hosts

Sending passive check results cannot be done via nrpe client as this is enabled and used for active checks from the Nagios server.

In the case of passive checks, the result needs to be submitted by the client itself to Nagios server hence, this is achieved by nsca (http://nagios.manubulon.com/traduction/docs25en/addons.html#nsca) addon.

This addon consists of a daemon that runs at the server-side i.e. Nagios host.

This daemon will listen to connections that are coming from Nagios clients.

Nagios clients send information to NSCA daemon which is then converted (into Nagios format) & submitted to Nagios for showing the state at the dashboard.