Nagios Alternatives: Best Commercial & Open Source of 2023 (2023)

Nagios, one of our all time favorite network monitoring tools for Linux, can sometimes be a little overwhelming when setting up, maintaining and keeping up to date.

All configurations are done through config files and can be cumbersome and quite frankly, inconvenient.

Many admins and engineers who are not familiar with Linux/Unix commands and architecture prefer to work within Windows Server/Desktop instead, with a more Fully Automated approach.

On top of the Operating system constraints, there are a ton of plug-ins and add-ons that add to the headache of keeping Nagios up-to-date and functioning properly in a dynamic environment with the wave of BYOD in the workforce.

Some features we're looking for in a Replacement are:

  • Easy and Fully Automated Network Discovery and SNMP Scanning functionality (without the need for Add-ons or Plugins)
  • Commercial, Enterprise and Open-Source Alternatives (for those looking for Freeware alternatives)
  • GUI Based Web Interface and Configuration for Windows OS
  • Built-in Network Analyzer for Netflow and other flow protocols, including sFlow, IPfix, etc
  • Network Map and Topology
  • Alerts, Notifications, and Triggers with Email, SMS, and other communication channels

Here's a list of Nagios Alternatives/Replacements of 2023:

We'll first start off with a list of Commercial alternatives for those looking for a commercially supported software solution, as some are looking for 24/7/365 Support and Troubleshooting.

Most of these have a Free Trial period (30-60 Days) or Freeware version where you are only allowed a certain number of Nodes or Sensors.


is one of the Most well-supported monitoring solutions around, specifically when it comes to Migrating from Nagios.

SolarWinds has a built-in Nagios script importer that allows your to use your existing Nagios scripts that you've developed over the years and directly import them into SAM.

For many, the feeling of losing all your work and customization within Nagios is now saved due to this awesome feature.

We've seen very few monitoring solutions offer such streamlined support for migration from Nagios into their own platform.

SAM boasts support for over 200 and more applications that are directly built into the software that will allow you to get setup within hours, instead of days or weeks.

Their extensive community of IT pro's and engineers have also developed additional templates and support for custom solutions as well.

SAM scales up to any number of Nodes and sensors and allows you to monitor thousands upon thousands of systems, services, resources, hardware, and anything else you may want to keep track of.

Their AppInsight dashboard helps you visualize and pinpoint issues quickly and efficiently to help you determine the root cause of the problem or issue.

SAM supports agent-less and agent-based monitoring, as well as an intuitive network mapping and discovery feature for quickly mapping out your topology quickly and automatically.

The feature set goes far and beyond what Nagios has to offer, we really suggest downloading a Free Trial and configuring it quickly in your environment.

With their 200+ built-in monitoring templates, you'll be up in a couple hours.


  • Designed with large and enterprise networks in mind
  • Has some of the best alerting features that balance effectiveness with ease of use
  • Supports both SNMP monitoring as well as packet analysis, giving you more control over monitoring than similar tools
  • Uses drag and drop widgets to customize the look and feel of the dashboard
  • Robust reporting system with pre-configured compliance templates


(Video) Best Open-Source Network Monitoring Tools 2022 - 2023

  • This is a feature-rich enterprise tool, small networks may find it overwhelming

Price: To figure out your network requirements and pricing, start of with a 30-day free trial.


2. Paessler PRTG – FREE TRIAL

Paessler PRTG is another great alternative to Nagios, in terms of a commercial replacement.

They even have a Free Version that allows you to monitor up to 100 Nodes at No additional cost.

Anything over those initial 100 nodes of monitoring will incur licensing fee's but their prices seem to be on par with the rest of the commercial offerings here.

PRTG is known for its high-level overview of your infrastructure and monitors it in a way that gives you complete control and oversight into all systems, IP Interfaces, bandwidth and bottlenecks on your network. With their intuitive network maps, alerting and trigger systems, and automatic network discovery, this makes for a great replacement.


  • Drag and drop editor makes it easy to build custom views and reports
  • Supports a wide range of alert mediums such as SMS, email, and third-party integrations into platforms like Slack
  • Supports a freeware version


  • Is a very comprehensive platform with many features and moving parts that require time to learn

Pricing: You can start with a 30-day free trial.


Related post: We've compared PRTG vs Nagios here.

3. ManageEngine OpManager – FREE TRIAL

ManageEngine is consistently redefining the way we look at network management and monitoring, with their OpManager offering which has a full array of features that really make this a great all-in-one tool for any Network Engineer.

Some features that stuck out to us was monitoring up to 1,000,000 interfaces or 50,000 devices from a single server, as well as 3D DataCenter layout and configuration for Visualisation. This includes Network Topology Maps, Auto-discovery, WiFi monitoring, heat maps and other functions.


  • Can monitor bandwidth consumption as well as alert to configuration changes that could impact network performance
  • Can monitor bandwidth and resource consumption on the application level, and even drill down to identify specific users consuming the most resources
  • Supports email, SMS, and webhook for numerous alerting channels
  • Integrates well in the ManageEngine ecosystem with their other products


  • Takes time to full explore the all the options available in the ManageEngine software suite
(Video) DevOps Monitoring Tools | Top 5 Free Monitoring Tools for DevOps

Price: Work out your network requirements with a 30-day free trial.


Open-Source Replacements

Next, we'll go over some alternatives that are Open-Source and have smaller support communities, but also perform as well as the others listed above.

More often than not, many of the below open-source solutions require greater knowledge and know-how when initially configuring and setting up the software.

On top of that, many of the software solutions below might also need 3rd party plugins or Add-ons to complete certain tasks or perform monitoring on certain brands or manufacturers of hardware, as well as other basic functions that we've mentioned in the list above.

4. Zabbix

Zabbix is one of the top open-source competitors to Nagios due to its scalable design and light overhead, claiming that it can operate with just 256MB of Ram.

Fine tuning Zabbix is a little cumbersome, as many have stated, but once your've figured out all the quirks and details, you'll be chugging along nicely.

Once again, Zabbix, like most Open-source network monitoring software, can monitor Windows based machines with agents, but will not run on them as a central server. Zabbix can be installed on the following OSes:

  • Linux
  • FreeBSD
  • NetBSD
  • OpenBSD
  • HP-UX
  • Mac OS X
  • Solaris


  • Open-source transparent tool
  • Uses both SNMP and ICMP for broader monitoring ranges
  • Offers useful templates for quick insights


  • No paid support option – not ideal for large enterprise environments

Download information:

5. OP5

OP5 has close relations to Nagios and their development team, in specifically, 2 of their developers were on the Nagios development teams.

Having a close relationship to Nagios has helped them developed OP5 into a easier and more streamlined program than Nagios is.

As many have seen and dealt with, Nagios is very time-consuming to setup and config (via config files) and many times there is only 1 or 2 admins who are familiar with the change process of monitoring systems and nodes.

Op5 took additional steps to make adding nodes and servers very easy and streamlined to save time when adding new Systems to monitor.

All of this is done through their Web Interface and this process has proved time and time again to save Sys Admins and engineers on setup time and configurations.

(Video) Top 10 | Best Network Monitoring Tools | 2022

They've also added a lot of nifty features including “undo” functionality that will allow you to roll-back changes in-case of mis-configuration.

OP5 put out a great video on how they stack up against Nagios, its definitely worth a watch if your considering moving over to OP5 from Nagios.


  • Focuses primarily on offering their services to large enterprises
  • All features and interfaces are designed to scale and handle large amounts of data well
  • Simple widget customizations can be added or removed
  • Offers geolocation mapping, and dependency mapping to help visualize complicated network services


  • Must contact sales for accurate pricing information
  • The interface could be made more user-friendly with fewer menu options

Download Information:

6. Zenoss Core

Zenoss Core offers 3 version of their Open-source solution, including a Free Versions that monitors up to 1000 Devices.

As with most of the other software packages here, support for the free version can be obtained through their community forum, which isn't always guaranteed to give you a proper solution or answer to any issues you are dealing with.

Their 2 paid options, Zaas and Zenoss Service Dynamics, allow you to monitor not only On-premises hardware and software, but Cloud based resources as well.

The benefit of using a paid-option of Zenoss Core is the level of service you get from their Support team, along with access to Full Analytics reports and Unlimited Device monitoring. Zenoss Core can install natively on Redhat Linux and CentOS, although Ubuntu and Debian are also options as well.


  • Offers Fortinet monitoring through a simple plugin
  • Uses network discovery to automatically pull in new devices that enter the network
  • Supports Cisco Layer 2-4 devices


  • Support is only for paid tiers

Download Information:

7. OpenNMS

OpenNMS now comes into two distinct versions, or “flavors” as they call it: Horizon and Meridian.

Horizon is the free offering that you can download, install and get monitoring without much effort and support, other than their community boards/forums.

It is the latest and the greatest with all the updates added to the distribution as they come out.

Meridian on the other hand is their Enterprise Grade Subscription service that comes with Pre-Configured reports, layouts, alerts, workflows, and more.

Meridian version has several added benefits compared to the free version, but nevertheless, their community forums and user generated templates really help in setting up the monitoring solution.

(Video) How to Monitor Entire Infrastructure using Open Source Enterprise Solution - 2023

OpenNMS gives you the option to use either RRDTOOL, JRobin, or NewTS for maximum flexibilty within your environment.

Surprising, OpenNMS has a Windows Server installation, but they do recommend installing and running on LINUX.

Full Feature Set can be found here


  • Open source projects, lots of room for customization, and personalized add-ons
  • Has a large amount of documentation available
  • Features two versions, a stable version and a beta test version for new features
  • Offers a wide range of monitoring options and flexible alert notifications


  • Users rely on help documents and forums for support, which isn’t always the quickest way to resolve issues

Download Information:

8. Munin

Munin is a not-so-popular monitoring solution, but nonetheless gives you a good replacement if you would like to stick to an open-source solution. Munin is based on Perl and has RRDTOOL integrated into it for graphing functionality.

As many other monitoring solutions function, Munin operates as a master/node configuration and poles nodes continuously for new information and metrics and maps them out as needed using RRD files.

Munin has the “what's different today” mindset to ensure that you can see whats different than the prior day and what resources are being used on what machine/system.


  • Completely free tool
  • Easy to use
  • Offers live performance graphs
  • Uses lightweight graphics that get the job done


  • Only available on Unix and Linux platforms

Download Info:

Related Posts:

Nagios vs Cacti Comparison

Nagios vs Icinga Comparison


1. Best Server & Application Monitor for free with Checkmk
2. Best Docker Container Monitoring Tools - Free and open source
3. 👉 Which is Better GRAFANA or ZABBIX? | Watch This BEFORE You Choose Your Monitoring Tools 📈📈 👈
(Angel Berniz)
4. Top 20 Best Open Source Monitoring Tools for Servers, Networks & Apps
(Cloud Infrastructure Services)
5. How to monitor your network for free with Zabbix
6. 💥 How to Monitor Windows Machines with Nagios for FREE
(SkillsBuild Training)
Top Articles
Latest Posts
Article information

Author: Merrill Bechtelar CPA

Last Updated: 05/27/2023

Views: 6083

Rating: 5 / 5 (70 voted)

Reviews: 85% of readers found this page helpful

Author information

Name: Merrill Bechtelar CPA

Birthday: 1996-05-19

Address: Apt. 114 873 White Lodge, Libbyfurt, CA 93006

Phone: +5983010455207

Job: Legacy Representative

Hobby: Blacksmithing, Urban exploration, Sudoku, Slacklining, Creative writing, Community, Letterboxing

Introduction: My name is Merrill Bechtelar CPA, I am a clean, agreeable, glorious, magnificent, witty, enchanting, comfortable person who loves writing and wants to share my knowledge and understanding with you.