After installing nagios, you may face some issues
Some hosts are not able to be ping due to firewall. By default, Nagios use the check_host_alive by default at /etc/nagios/objects/template.cfg. check_host_alive uses ping to check whether the host is alive. So your nagios web admin will see a host down status.
To use another commands to replace the check_host_alive with check_http which is more useful as a "check-alive-status", change it at the /etc/nagios/objects/hosts.cfg file. This will override the default at /etc/nagios/objects/templates.cfg
We assume that check_http is already define in the /etc/nagios/objects/command.cfg
define host{
use windows-server
host_name xxxx
alias xxxx web server
check_command check_http
address xxx.com.sg
contact_groups admin
}
