Activating Changes

Finally, you need to activate the changes by clicking on the highlighted field with the yellow ! at the top right corner that counts the number of changes. After that, click on Activate on selected sites, and you will have successfully added the first host to your monitoring.

The activation of changes is a safety mechanism. All changes made will be listed under Pending changes (Figure 7). You can review any listed changes before they affect your monitoring. Checkmk differentiates between the Setup menu as a configuration environment, in which you manage the hosts, services and settings, and the Monitor menu, in which the actual operational monitoring takes place. New hosts and other changes in the configuration initially have no effect on the monitoring. You need to activate these before they can go into production.

Figure 7: You'll have a chance to review pending changes before you activate them.

You find your host now under Monitor | Overview | All hosts. Click on a host, and you will see an overview of all the monitoring services of that host. Figure 8 shows the overview of my router. You can click on each service to see more details.

Figure 8: Viewing all the monitoring services on a host.

Conclusion

This article is intended as a proof of concept. I used the SNMP monitoring agent in the example because SNMP is supported on most home routers. However, be aware that there are some security concerns with SNMP. The US government Cybersecurity and Infrastructure Security Agency recommends that you only use SNMPv3 and has outlined additional precautions [6].

This tutorial ends here, but your real experience with monitoring has only just begun. If you want to continue, you should add your host server to the monitoring as well. Checkmk provides some lightweight, but powerful monitoring agents for server monitoring. You will find the agents for various operating systems, such as Windows and a number of Linux distributions, via the sidebar by clicking on Setup | Agents | Linux.

After you install, the procedure is similar: Add the host that you want to monitor, but you can leave the box Checkmk agent/API integrations unchecked and should not switch that to SNMP. By default, Checkmk assumes you are using Checkmk agents to monitor systems.

The Checkmk documentation [7], as well as in the official Checkmk forum [8], will provide answers for all your Checkmk questions.