How to Add and Monitor Network Switches and Routers in Nagios

This guide will walk you through the steps to add and monitor network switch, router and it’s active ports in Nagios.

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Enable switch.cfg in nagios.cfg

Uncomment the switch.cfg line in /usr/local/nagios/etc/nagios.cfg as shown below.

grep switch.cfg /usr/local/nagios/etc/nagios.cfg
cfg_file=/usr/local/nagios/etc/objects/switch.cfg

 

Add new hostgroup for switches in switch.cfg

Add the following switches hostgroup to the /usr/local/nagios/etc/objects/switch.cfg file.

define hostgroup{ hostgroup_name switches alias Network Switches }

 

Add a new host for the switch to be monitored

In the following example, I’ve defined a host to monitor the core switch in the /usr/local/nagios/etc/objects/switch.cfg file. Change the address directive to your switch ip-address accordingly.

define host{
use             generic-switch
host_name       core-switch
alias           Cisco Core Switch
address         192.168.1.10
hostgroups      switches
}

 

Add common services for all switches

Displaying the uptime of the switch and verifying whether switch is alive are common services for all switches. So, define these services under the switches hostgroup_name as shown below.

# Service definition to ping the switch using check_ping
define service{
use                     generic-service
hostgroup_name          switches
service_description     PING
check_command           check_ping!200.0,20%!600.0,60%
normal_check_interval   5
retry_check_interval    1
}

# Service definition to monitor switch uptime using check_snmp
define service{
use                     generic-service
hostgroup_name          switches
service_description     Uptime
check_command           check_snmp!-C public -o sysUpTime.0
}

 

Validate configuration and restart nagios

Now, verify the Nagios configuration to make sure there are no warnings and errors.

# /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg

Total Warnings: 0
Total Errors:   0
Things look okay - No serious problems were detected during the pre-flight check

Restart the nagios server to start monitoring the VPN device.

# /etc/rc.d/init.d/nagios stop
Stopping nagios: .done.

# /etc/rc.d/init.d/nagios start
Starting nagios: done.

Verify the status of the switch from the Nagios web interface: http://nagios-server/nagios as shown below:

 

That's all for now.