Nagios, 2nd Edition

2.2 Objects—an Overview

A Nagios object describes a specific unit: a host, a service, a contact, or the groups to which each belongs. Even commands are defined as objects. This definition has not come about by chance. Nagios is also able to inherit characteristics (2.11 Templates from page 75).

Object definitions follow the following pattern:

define object-type {
   parameter value
   parameter value
   ...
}

Nagios has the following values for the object-type:

host

The host object describes one of the network nodes that are to be monitored. Nagios expects the IP address as a parameter here (or the Fully Qualified Domain Name) and the command that should define whether the host is alive (see 2.3 Defining the Machines to Be Monitored, with host, page 62). ...