About Naemon

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Naemon Overview

More information about Naemon - including features and technical specifications can be found online at naemon.io.

What Is Naemon?

Naemon is an Open Source system and network monitoring application. It watches hosts and services that you specify, alerts you when things go bad and notifies you when they get better.

Naemon is based on Nagios 4.0.2 and aims to be a drop in replacement for Nagios.

Nagios used to refer to the community project, but when Nagios Enterprises was created, Nagios in all official communication started referring to Nagios-the-product (XI). As Nagios Enterprises had an open core model, they started to refer to their open core as Nagios Core. Naemon Suite is currently roughly equivalent to Nagios Core, which makes Naemon Core the equivalent of “Nagios Core Core”.

Naemon is the general term of the entire “Naemon Suite” that consists of two different parts, Naemon Core and the Thruk Monitoring Webinterface. We will generally refer to Naemon Suite as just Naemon.

Some of the many features of Naemon include:

  • Monitoring of network services (SMTP, POP3, HTTP, NNTP, PING, etc.)
  • Monitoring of host resources (processor load, disk usage, etc.)
  • Simple plugin design that allows users to easily develop their own service checks
  • Parallelized service checks
  • Thruk Monitoring Webinterface to edit settings and view current network status, problem history, log files, sla reports, dashboards, business processes, etc.
  • Ability to define network host hierarchy using “parent” hosts, allowing detection of and distinction between hosts that are down and those that are unreachable
  • Contact notifications when service or host problems occur and get resolved (via email, pager, or user-defined method)
  • Ability to define event handlers to be run during service or host events for proactive problem resolution
  • Automatic log file rotation
  • Support for implementing redundant monitoring hosts


Naemon core

The naemon core is the process that does the actual monitoring of your system.


Livestatus is an interface that your tools can use to query the Naemon core like a database. Read more about Livestatus.


Thruk is the UI shipped with the Naemon Suite.

The Thruk documentation is at its own page.


The monitoring application itself is quite useless without plugins to actually checks things for you. Check out monitoring plugins for a large, well maintained collection of core plugins.

The more esoteric your needs are, the higher the probability that your needs wont be covered by the monitoring plugins package. You can find a large body of plugins - maintained by their individual authors - at monitoring exchange. You can also easily write your own - see the monitoring plugins project.

Read more about the Plugin API.

System Requirements

The only requirement of running Naemon is a machine running Linux (or UNIX variant) that has network access and a C compiler installed (if installing from source code).

You are not required to use the CGIs included with Naemon. However, if you do decide to use them, you will need to have the following software installed…

  • A web server (preferrably Apache)
  • Perl


Naemon Core is licensed under the terms of the GNU General Public License Version 2 as published by the Free Software Foundation. This gives you legal permission to copy, distribute and/or modify Naemon under certain conditions. Read the ‘LICENSE’ file in the Naemon distribution or read the online version of the license for more details.



Several people have contributed to Naemon by either reporting bugs, suggesting improvements, writing plugins, etc. A list of some of the many contributors to the development of Naemon Core can be found in the THANKS file in the root of the Naemon Core distribution.

Downloading The Latest Version

You can check for new versions of Naemon at https://www.naemon.io/download.