Best open source network monitoring tools

As the demand for open source software continues to surge, the network management field has also seen a boost and the availability of tools that combine the two is high.

Instead of spending a small fortune paying for software that may or may not do what you need, look out for (mostly) free open source tools to monitor, configure and map your networked devices.

Here are some open source network monitoring tools to help IT admins in their job.

Read next: 13 best free and open source inventory management systems

security monitoring
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Graphite

Graphiteis a free open source network monitoring tool that is built to collect, store and display time-series data in real time.

The software is typically used by businesses to track the performance of websites, applications, business services and servers and is compatible with selected cheap hardware and new cloud infrastructure.

It was originally designed in 2006, however in 2008 Orbitz released Graphite under the open source Apache 2.0 licence.

Prometheus
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Prometheus

Prometheusis an open-source network monitoring system, originally built by SoundCloud in 2012.

It is hosted by the Cloud Native Computing Foundation (CNCF) and is designed to monitor time series data, while also offering features to alter and autoscale.

Prometheus is widely used to monitor Kubernetes clusters and offers a standalone server which enables it to be supported by other monitoring tools like Google Cloud.

Paessler PRTG
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Paessler PRTG

Paessler PRTGprovides all-in-one network monitoring software for users to locate and avoid network errors across all areas of their network. This is known as centralised monitoring.

The software tool is built to notify a user before the problem appears, saving users both time and energy. It is available for desktop and mobile, allowing devices in a data centre to be monitored using the mobile app.

Paessler PRTG is available in different languages including German and Spanish. It also offers unified monitoring for services other than network such as performance, hardware and cloud.

The software was originally developed out of the open source Multi Router Traffic Grapher project – so technically this product is proprietary but a freeware version is available.

The free plan supports 100 sensors and beyond that pricing is flexible, starting from €1200 (£1049.25) for 500 sensors.

security monitoring
Thinkstock

Graphite

Graphiteis a free open source network monitoring tool that is built to collect, store and display time-series data in real time.

The software is typically used by businesses to track the performance of websites, applications, business services and servers and is compatible with selected cheap hardware and new cloud infrastructure.

It was originally designed in 2006, however in 2008 Orbitz released Graphite under the open source Apache 2.0 licence.

security monitoring
Thinkstock

Graphite

Graphiteis a free open source network monitoring tool that is built to collect, store and display time-series data in real time.

The software is typically used by businesses to track the performance of websites, applications, business services and servers and is compatible with selected cheap hardware and new cloud infrastructure.

It was originally designed in 2006, however in 2008 Orbitz released Graphite under the open source Apache 2.0 licence.

security monitoring
Thinkstock

Graphite

Graphiteis a free open source network monitoring tool that is built to collect, store and display time-series data in real time.

The software is typically used by businesses to track the performance of websites, applications, business services and servers and is compatible with selected cheap hardware and new cloud infrastructure.

It was originally designed in 2006, however in 2008 Orbitz released Graphite under the open source Apache 2.0 licence.

Manage Engine

Manage Engine

Manage Engine offers a free network monitoring tool called OpManager. It provides network, server and virtualisation monitoring and also allows users to monitor 10 of the most critical devices like routers, firewalls, and switches for free.

The network monitoring capability enables users to monitor critical metrics such as errors, disk utilisation, and CPU to optimise network performance in real time.

OpManager also provides charts and reports to analyse the performance of devices over a period of time.

Zenoss Core

Zenoss Core

Zenoss Core is a free open source infrastructure monitoring platform that offers unified monitoring and correlation of networking events.

It also provides performance and availability monitoring for metrics such as inbound and output traffic speeds, as well as fast discovery and notification when network devices or interfaces go down.

Zenoss Core users can enhance network monitoring with ZenPacks, plug-ins that are developed to the features of specific network devices and systems. It uses standard APIs and protocols to monitor specific network systems.

Ganglia

Ganglia

Ganglia is a scalable, distributed monitoring tool for high-performance computing systems, clusters and networks.

An open source project which was developed out of the University of California, Ganglia leverages widely used technologies such as XML for data representation.

It can monitor clusters of servers of up to 2000 nodes, whilst providing live network status updates.

Centreon

Centreon

Centreon is an open source monitoring solution. It is both comprehensive and scalable, providing a robust platform with powerful data handling and safeguards for reliable monitoring.

Centreon delivers infrastructure systems and network performance monitoring for an unlimited number of devices.

NetXMS
© NeXMS

NetXMS

NetXMSoffers an enterprise-grade open source network management and monitoring programme with a simple user interface on Windows and Linux.

NetXMS provides distributed network monitoring, automated network discovery and detailed reporting for all layers of your IT infrastructure, with a relatively simple installation process.

Plus, the server footprints and agents are pretty lightweight for such a comprehensive product.

Pandora FMS

Pandora FMS

Aimed at the enterprise, Pandora FMS offers a sleek and uncluttered user experience with an easy-to-read quick insight tool providing important network stats such as the status of the network, open alarms, the number of agents deployed and a list of any recent tasks being performed.

Pandora FMS can perform network diagnostics without external access, meaning that users could receive a faster response to any network issues. In fact, Pandora FMS says that its monitoring response rate is around 10 seconds for both agent modalities.

Cacti

Cacti

Initially released in 2001, Cacti is an open source web-based network monitoring and graphing tool designed for data-logging. It can be used to show network data over time, such as CPU load or bandwidth utilisation.

Cacti is a front end application to RRDtool, an open source database tool for storing data that changes over time, using SNMP as its default collection method, but if you prefer local Perl of PHP scripts, you can used those as well.

Its latest version 0.8.8h was released in May 2016 with key features including unlimited graph item, auto-padding support for graphs, graph data manipulation, custom data-gathering scripts, built-in SNMP support, graph templates, data source templates, host templates and user-based management.

GroundWork Monitor Core

GroundWork Monitor Core

GroundWork Monitor Coreis a platform for monitoring networks, applications and cloud computing usage. The open source version includes a license to monitor up to 50 devices and community-based support, and there is also a business edition of the software.

In terms of its network managing capabilities, GroundWork offers auto-discovery and maintenance of network and devices, topology, alarm control, data collection via API, SNMP, IPMI and support for OpenDaylight SDNs.

GroundWork also offers storage management, supporting a large range of enterprise vendors such as NetApp and EMC along with data collection from disk, block or object storage and storage slowdowns and outages visuals.

Due to GroundWork's one-stop-shop approach to network management, this sort of suite might suit larger businesses and enterprises looking for an established brand rather than a developer-focused tool like Big Brother or Big Sister.

Hyperic
© VMware

Hyperic

Hyperic, from VMware is intended for monitoring custom web applications and their performance across physical, virtual and cloud environments. It works across application servers, web servers, databases, operating systems, hypervisors, messaging servers and directory servers.

Hyperic provides infrastructure and OS monitoring, detailed reporting, application and middleware monitoring, alerts and remediation workflows and a universally-extensible API.

This network monitoring tool offers an enterprise version that improves on the alerting function and is better able to create baselines.

Observium

Observium

Linux-based, Observium is an auto-discovery network monitoring tool. According to the site, it's "professionally developed and maintained by a team of experienced network engineers and systems administrators, Observium is a platform designed and built by its users."

Observium offers both a community edition and a professional edition and uses RRDTool for buffer storage and graphing capabilities with an easy to use dashboard and reporting features. However, it does lack report exporting which could be an issue for some businesses.

Community users will benefit from full auto-discovery of supported devices and metrics, network-mapping through discovery protocols, automatic recognition of hundreds of devices and six-monthly releases.

While users of the professional edition will receive all community features plus real-time software updates and fixes, rule-based automatic grouping, threshold and state alerting system and traffic accounting system.

Zabbix

Zabbix

Described as an enterprise-class monitoring tool, Zabbix offers real-time monitoring, auto-discovery, mapping and scalability from data collected from servers, virtual machines and network devices.

Zabbix's enterprise monitoring software provides users with built-in Java application server monitoring, hardware monitoring, VMware monitoring and CPU, memory, network, disk space performance monitoring.

This network monitoring tool offers enterprise-level software able to perform 3,000,000 checks per minute, with added security and data centre monitoring available.

Nagios

Nagios

Nagiosis an open source software tool for monitoring IT infrastructure and viewing current status, historical logs and basic reports. Nagios users can monitor system metrics, network protocols, applications, servers, network infrastructure and receive failures alerts.

Nagios offers three types of network management tools, Nagios XL, Nagios log server and Nagios network analyser with Nagios XL being the most fitting for network monitoring (although the others do offer network monitoring support).

Nagios XL offers enterprise-level network monitoring, providing users with bandwidth reports, heartbeat monitoring, custom action URL, email reports and remote machine monitoring. The enterprise upgrade providing web-based server console access, business process monitoring, audit logging and automated decommissioning as well.

NetDisco

NetDisco

Designed for Unix-like operating systems, NetDisco offers web-based auto-discovery of networked devices via NSMP, creating pictures of networks, designed for moderate to large networks.

This network management tool can be used to locate devices, create an inventory and report on IP address and switch port usage.

NetDisco users can locate a machine on the network by MAC or IP, turn off a switch port, or change the VLAN or PoE status of a port, inventory your network hardware by model, vendor, software and operating system and create detailed pictures of your network

OpenNMS

OpenNMS

Initially released in 1999, OpenNMS provides event management, service monitoring and performance measurement designed for large to enterprise-level businesses.

Key features enterprise users will benefit from includes external scripts, send alerts to on-call system engineers, extend the Java native notification strategy API, request Tracker (RT) integration, high-level alarms, IPv4 and IPv6 network reachability over ICMP, test statuses, and node inventory information.

It's enterprise service or 'flavour' Meridian offers preconfigured events, notices, data collection, workflows and reports in addition.

RANCID

RANCID

RANCIDsounds like a negative name, until you learn that it stands for Really Awesome New Cisco config Differ. That means it monitors a router or other device's configuration and maintains a history of any changes. And also despite the name RANCID supports many vendors' devices, including Juniper routers, HP switches, Redback NASs and many others as well as extending support to Observium.

RANCID supports many vendors' devices, including Juniper routers, HP switches, Redback NASs and many others as well as extending support to Observium.

RANCID offers a variety of network management features including a login to each device in the router table (router.db), run various commands to get the information that will be saved, email any differences from the previous collection to a mail list and commit those changes to the revision control system.

Xymon

Xymon

Another network monitoring tool to consider is Xymon (formerly called Hobbit). Xymon monitors servers, applications and networks, offering information about the health of all of those networked components via web pages.

Its site says it was inspired by Big Brother, and like Big Sister, it attempts to address perceived shortcomings of Big Brother BTF, such as performance. Xymon is also intended to be easier to deploy and is free.

Big Brother BTF

Big Brother BTF

Big Brother was created in the mid-1990s to monitor networked systems and was later acquired by Quest Software, which was subsequently purchased by Dell in 2012.

Many other network monitoring tools has been modelled on Big Brother so it's a good place to start for a vast and detailed forum and helpful developer community.

Alongside an open source version available for students and non-commercial, a business version, called Big Brother Professional Edition, is also available.

Big Sister

Big Sister

Big Sistercreator Thomas Aeby said he was impressed by Big Brother's network monitoring but wanted to change to improve the performance, reduce the number of alarms when something goes down and make other enhancements.

Big Sister offers network monitoring, a node director, doxygen filter and a web application framework, working as part of Unix derivatives and Microsoft Windows operating systems.

Big Sister can be useful for IT admins wanting to monitor networked systems, be notified when systems are becoming critical, generate a history of status changes and log and display a variety of system performance data.

Copyright © 2018 IDG Communications, Inc.