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The Top 5 Free and Open Source Network Monitoring Software

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UPDATE 5/24/2017: This post has been updated with new options and additional information based on comments and feedback from readers since the original version went live. We’ve also included summaries of user reviews to better reflect actual users’ experience with different systems.

Love network monitoring software but need some that’s a bit more within your price range? How about something that’s not only free, but customizable to meet the needs of your company and its growing network?

top 5 network monitoring software

This is where free and open source network monitoring software comes in. Not only are there free and open source network monitoring solutions available, but the options are diverse and plentiful.

I understands your hesitation, though. Nothing’s really free. . . is it? I mean, if it’s free there must be something lacking, something wrong with it, right?

Not this time!

Below, I’ve outlined some of the most popular free network monitoring software, listing their pros and cons (no cost here, people), so that you can make the right decision for your business, regardless of its size.

Icinga 2


This 100% free and open source network monitoring option uses both MySQL and PostgreSQL (two free and OS database management systems), and is even Nagios backwards compatible.


The great thing about Icinga is that it’s always updating, and with Icinga 2, users can expect “a new configuration format that is intuitive to write, efficient to execute and even adjusts to the changing conditions of your environment at run-time.” In other words, it’s a bit more user-friendly than its earlier versions.

Icinga offers three command types (check, notification, and event command), which can be given default values, custom attributes, runtime macros, and conditional behaviours. Icinga 2 also hosts improved notification settings to tackle network issues and problem faster.

As with many free and open source options, there’s a committed team dedicated to addressing issues and fixing patches within the software. You can even join the team here.


Because updates to Icinga depend largely on team service and support, you may have to wait until the problem comes to the attention of the support team to be fixed.

What users say

Leave a review for Icinga here.

Nagios Core


Nagios Core boasts comprehensive monitoring as well as problem remediation and proactive planning to keep your network and devices in check.


Nagios Core can monitor system metrics, network protocols, applications, services, servers, and network infrastructure within a centralized location, complete with detailed status information on all devices. Alerting is another major benefit to Nagios Core and has the potential to save you from  critical infrastructure incidents that can debilitate your system. These alerts can be delivered through email, SMS, or custom script. Nagios Core also offers users the ability to plan for future upgrades and even integrate with in-house or third-party applications and community-developed add-ons due to its multiple APIs. Users can also schedule network downtime during maintenance and upgrades.


Nagios Core is free, but only for a single license.

What users say

Leave another review for Nagios here.


If you’ve been in IT for the last decade, there’s no way you haven’t heard of Spiceworks, which offers many free IT management tools, including network monitoring, and boasts over six million IT professionals in its network.


There are no limits to the number of devices you can monitor with Spiceworks Network Monitor, nor is there a limit to the number of users with access to the tool. Plus, unlike lots of free tools, phone and help desk support is free, in addition to access to the large Spiceworks community forums.

You can use the tool to monitor servers, switches, SNMP devices, and services, as well as connect to other free tools like Connectivity Dashboard, Blacklist Checker, and IP Lookup for increased functionality. You can also set up customizable notifications and restart services from within the app.


Spiceworks only runs on Windows servers, so you’ll have to check into another tool if you have a different server type. Also, Spiceworks is free because most of its revenue comes from the sale of ad displays in its network. It’s a small price to pay for a free solution, but it’s something to think about before you install.

What users say

Leave another review for Spiceworks here.

Observium Community


Observium Community is another great option for those looking for a low-maintenance, free, and OS network monitoring software, designed and built by its users.


Features of Observium Community include six-month software updates to fix patches and potential problems as well as full auto-discovery of your devices and metrics. User will also be able to map their network through discovery protocols, which should be painless considering Observium Community can automatically recognize hundreds of devices. This solution is best used for small non-critical deployments, home use, evaluation, or even lab environments. The most recent version was updated October 26, 2016.


Unfortunately, because this is a free version of Observium, users miss out on options that come with the paid edition, like realtime software updates and fixes or a threshold and state alerting system. Also, the wait time between updates (six months) may be inconvenient to those experiencing software problems.

What users say


Leave a review for Observium here.



First released in 2001 and formed as an official company in 2005, Zabbix is a free enterprise-class monitoring solution for those looking to get a handle on their network.


This free and open source network monitoring software touches on multiple agentless monitoring, VMware (virtual machine) monitoring, as well as database and hardware monitoring. While Zabbix targets enterprise-level businesses, this solutions does offer scalability and can “process more than 3,000,000 checks per minute using mid-range hardware and collecting gigabytes of historical data daily.”

There’s no vendor lock-in or limitations on the number of monitored devices, meaning you can use Zabbix to keep tabs on thousands of devices. Built-in Java Application Server Monitoring and support for both IPv4 and IPv6 is also available as well as encryption support and a secure SSL connection for users and servers.

A new version of Zabbix, Zabbix 3.2, boasts a new web interface, encryption, and authentication.


Zabbix only works on these supported platforms: Linux, IBM AIX, IBM Power8, FreeBSD, NetBSD, OpenBSD, HP-UX, MAC OS X, and Solaris. Windows (since 2000) only operates on Zabbix Agent. Those with other platforms will have to find another solution. Furthermore, because this software is aimed at enterprise-level businesses, smaller companies may have to look elsewhere for a smaller scale solution.

What users say

Leave another review for Zabbix here.

Zenoss Core


While more limited, Zenoss Core still includes many of the features of its enterprise counterpart, Zenoss Service Dynamics.


In addition to a customizable web-based console and dashboards, Zenoss Core includes device discovery, modeling, and classification with agentless data collection and event monitoring to prevent network incidents. Many of Zenoss Core features are limited in comparison to Zenoss Enterprise, though it still offers unified monitoring, event management, reports, and a support community, which you can access here.

Community members have also created more than 200 “ZenPacks,” many of which are open source, so you can expand some of Zenoss Core’s functionality.


Zenoss Core only works for up to 1,000 devices. Those needing more can opt in for their paid solution or search for another free and OS offering.

What users say

Leave another review for Zenoss here.


But what are your thoughts on  free or open source network monitoring software? Has it really saved your team money or is the cost in time and maintenance more trouble than it’s worth? Let me (and other readers!) know in the comments.

And of course, if there are any other open source network monitoring software solutions that you think should be included on this list, let me know about them in the comments below.

Looking for Network Monitoring software? Check out Capterra's list of the best Network Monitoring software solutions.

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About the Author

Jennifer Champagne

Jennifer Champagne is a writer for Capterra, specializing in IT, hospitality, and real estate management. In her spare time, she enjoys reading and spending time with friends and family.


Thanks For Sharing a Such a Nice Post, Blog Post is informative and Useful, Network Motioning software Important Software , You have Mention Each software Pros & cons, so that we can make the right decision for your business, regardless of its size.

Glad I could help, Paula!

What about ones that monitor workstations? OS updates, Antivirus updates, backups working, etc… That kind of stuff?

AuditQi (google it), is targeted at updates and the status of windows PCs and and also provides limited user monitoring to assist admin staff, its open source, GPL3. It logs information to a central MySQL database and the current users and their machine’s status are displayed via your browser. Its also fairly easy to select the sources of tracked information and extend by writing your own custom reports if you have an MS access license.

[…] crashes. When team members are located in different location , it’s a good idea to use virtual incident management software . This software helps in exchanging information in real-time among the team […]

This is a nice list of options, Jennifer. Hyperic HQ, VMWare’s solution for monitoring and managing physical, virtual, and cloud server environments, and Groundwork are both worth checking out as well.

What users say – This is one of the best website which i have been using always whenever i need to buy something from the providers

I had a question about your list of open source NMSes. Can you tell why you did not include OpenNMS?
Thank you
Dr. Larry McMahan

NMIS is a great opensource network monitoring tool, surprised it’s not listed.

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