Nagios – network/device configuration

If you don’t have working Nagios installation fell free to follow Nagios – New installation on Debian 9 link.

We will need to add folder structure (for better organization) to nagios config file:

# edit nagios.cfg
mcedit /usr/local/nagios/etc/nagios.cfg

# lets add out root dir that will store our config files for device/network
# this way we don't need to type cfg_file for each .cfg file out there
cfg_dir=/usr/local/nagios/etc/devices

# save file and create proper directory
mkdir /usr/local/nagios/etc/devices
cd /usr/local/nagios/etc/devices

Not everyone have luxury to always use smart switches around network – those make live a lot easier, but life is not a dream 🙂

Let us make a template for non-smart aka no-ping switches:

define host{
        name                            noping-host    ; The name of this host template
        notifications_enabled           1       
        event_handler_enabled           1       
        flap_detection_enabled          1      
        process_perf_data               1      
        retain_status_information       1       
        retain_nonstatus_information    1       
        notification_interval           0
        notification_period             24x7
        notification_options            d,u,r
        contact_groups                  admins
        max_check_attempts              5
        address                         127.0.0.1      ; Just so we don't have to write it all the time
        register                        0      
        }

Now we can define few switches like this:

define host{
            use noping-host
            host_name switch-number-1
            alias Switch Number 1
            icon_image switch40.png
            statusmap_image switch40.gd2
            parent name_of_parent_host_name  ; use this to make tree on map
            initial_status u
}

You can most variables put to template file so there will be even less writing

Most common type of templete is: linux-server (you can check others in /usr/local/nagios/etc/objects/templates.cfg )

After making few .cfg files inside our directory remamber to chown nagios:nagios -R /usr/local/nagios/etc/devices/ to avoid erros and restart nagios