Lack of Automatic Device Discovery
In a simple network with not many devices and services, generating configuration files would
not be difficult to do manually or with configuration tools discussed above. However, if the network
consists of many devices (hundreds or thousands hosts), this becomes a difficult and tedious task.
Automatic discovery of servers and routers in the network would be a welcome option. Examples of
plugins that can do this are NACE [26], check_find_new_hosts [27], Nmap2Nagios [28],
Nmap2Nagios-ng [29]. NACE queries information from network and automatically creates host and
service definitions for hosts on the network. check_find_new_hosts can scan a subnet to find hosts that
Nagios is not monitoring and add them to Nagios. Nmap2Nagios and Nmap2Nagios-ng are perl-scripts
that convert Nmap’s host scan output into Nagios configuration files. These tools allow Nagios to scale
well in terms of automatic configuration.