Monitoring through SNMP using Check_MK

Many devices like Routers, Switches, Sensors or Operating Systems could be monitored via SNMP (Simple Network Management Protocol). Before you continue, make sure you already have read Monitoring through Check_MK.

Try to fetch SNMP data from the target device

Before you start make sure your monitoring server is able to query data from the target device via SNMP. You can use the program snmpwalk to test if you can reach the target device.

In this example we query a Ubuntu Linux running snmpd using SNMP Version 2c with the community public.

snmpwalk -v2c -c public

You should get an output similar to this:

If not check if your firewall blocks the connection or if you are using a wrong version of SNMP.

Monitor a Linux host through SNMP via Check_MK

After you created the host in the openITCOCKPIT interface click on " Check_MK discovery"

Select "Execute SNMP discovery" from the list and click on "Execute discovery".

The system will ask you for the required SNMP parameters. The SNMP configuration will be saved per host so you don't have to type in this data again.

Click on "Save and run SNMP discovery" to continue.

Depending on which device you are going to discover it could happen that the Objects select box is empty and the information text Before you are able to monitor the following metrics, it is required that an appropriate service template has been created. followed by a table appears.

In this case you need to create the required service templates manually. We will do this in the next section.

Create missing service templates for Check_MK

As already mentioned sometimes it is required to create missing service templates.

Open a new Browser windows and navigate to Discovery MK Servicetemplates and press New.

Create service template for hr_fs

It is recommended to use the same name for the service template, as Check_MK uses (MK Check). In this case the MK Check is hr_fs so we use CHECK_MK_HR_FS as service template name. Also disable active checks and use check_none as check command. Set the value from Parameters out of the table as ARG1 and press Save.

Service template parameter overview:

Parameter Value
Template name CHECK_MK_HR_FS
Service name CHECK_MK_HR_FS
Enable graph Yes
Enable active checks No
Check command check_none
ARG1 {'levels_low': (50.0, 60.0), 'magic_normsize': 20, 'levels': (80.0, 90.0), 'trend_range': 24, 'trend_perfdata': True}
Check period 24x7
Max. number of check attempts 1
Check interval 60
Retry interval 60

Repeat this for all missing service templates.

Link service templates to MK Checks

Navigate to Discovery MK Checks and press New.

Now associate every MK Check to a service template.

Repeat this for new created service templates.

Create services

Now you are ready to create the services you like to monitor. Re-run the SNMP discovery and pick all services from the list.

To enable the new configuration, you need to "Refresh the monitoring configuration".

After a few seconds your services are monitored by the system.

Mix monitoring methods

You can also use SNMP and the Check_MK Agent at the same time. Just rescan the host, and select "Execute remote discovery" to also query the Check_MK Agent.

Pick all services you like to monitor - as you are used to from Check_MK and press "Save".

To enable the new configuration, you need to "Refresh the monitoring configuration".

Now some services are monitored through SNMP and others use the Check_MK Agent: