The Best Open-Source Network Monitoring Tools

Network engineers and admins know the power of network monitoring. It gives you the visibility you need into network health, alerts about anomalies or outages, and helps with capacity planning and troubleshooting. If you’re looking for commercial platforms first, see our best network monitoring tools and software. Although commercial solutions offer robust features, they can come with hefty licensing fees. Organizations looking to reduce operational costs often prefer to use open-source monitoring tools, for obvious reasons. Besides being free, many open-source tools offer enterprise-grade capabilities such as SNMP monitoring, real-time alerts, traffic analysis, and visualization dashboards.

However, not all open-source tools have the same capability. For a network admin, key considerations include the depth of monitoring (devices, traffic, applications), ease of deployment, integration with existing systems, alerting capabilities, and how well the tool can scale as the network grows. Some tools are lightweight and ideal for quick diagnostics, while others provide deep, customizable monitoring across distributed infrastructures.

This article explores the best open-source network monitoring tools currently available. We ranked and explained to help you find the right fit for your environment, budget, and technical expertise.

Here is our list of the best open-source network monitoring tools: 

1. Zabbix EDITOR’S CHOICE Enterprise-grade, full-stack monitoring with robust features, a strong user community, and excellent scalability.
2. Prometheus + Grafana The modern standard in cloud-native monitoring. Excellent for microservices, Kubernetes, and custom metrics.
3. LibreNMS Auto-discovery, SNMP-based, and user-friendly-great for managing network devices with minimal setup.
4. Icinga A modern fork of Nagios with a better UI and API; actively maintained and well-documented.
5. Netdata Super easy to install, visually appealing, and great for real-time performance monitoring.

Key points to consider before purchasing open-source network monitoring tools

When choosing an open-source network monitoring tool, as a network manager or IT buyer, you shouldn’t just focus on brand name or community hype. Based on a real-world evaluation framework, here are the key factors to keep in mind:

• Feature: Ensure the tool supports comprehensive monitoring—this includes network devices, servers, applications, and cloud infrastructure. Look for alerting, visualization, and support for modern protocols (such as SNMP, Prometheus exporters, and API access).
• Performance: You need real-time, low-latency visibility without overloading your infrastructure.
• Scalability: Your monitoring requirements will grow. Choose a tool that can scale easily, from a few nodes to enterprise or multi-cloud environments, without requiring a major re-architecture.
• Ease of Use: Installation, configuration, and day-to-day operation should be effortless. Consider tools with auto-discovery and user-friendly interfaces.
• Extensibility: Can the tool be extended with custom checks, integrations, or plug-ins? A flexible tool enables deep customization, which is critical in complex or evolving environments.
• Community Support: A strong, active community means regular updates, improved documentation, increased integrations, and faster responses when things go wrong. A stagnant project can leave you vulnerable and stuck, so pick one with an active ecosystem and development team.

Are open-source tools better?

Open source tools provide better visibility and customization options to organizations that value flexibility over a “done for you” experience. When tools are open source, any developer can view and modify the code to their liking. This transparency creates plugins, community-driven features, and continuous testing of the code’s stability and security.

With open-source software, you don’t have to worry about a vendor going out of business or being acquired by another company that wants to kill the product. Many times I’ve seen great products become unusable because a new owner mismanaged them. With open-source, you’re in control. Companies often rely on the product’s community for support, bug fixes, and features, but this can be dangerous.

Communities can slowly dissolve over time, leaving the product in an orphaned state. If this occurs, you’ll need to make sure your staff is experienced enough to resolve issues without the help of others.

There are pros and cons to running an open-source tool. Understanding the risks and rewards of doing so will help you know if it’s the right choice for your organization.

With that said, we’ve tested out some open-source network monitoring tools and created a list of our favorites.

The Best Open-source Network Monitoring Tools

1. Zabbix

Best For: Network and sysadmins, cloud infrastructure teams, MSPs, and mid-to-large organizations.

Price: Free and open-source

Zabbix monitors IT infrastructure like networks, servers, virtual machines, and cloud services. It was developed by Zabbix LLC, a Latvian company. Although Zabbix is open-source, it is also a closed-development software product. That means that the development process is controlled solely by Zabbix LLC, rather than relying exclusively on community contributions.

The core Zabbix team makes all decisions about features, changes, and releases. This development approach offers open-source freedom with centralized control, which can be a benefit or a limitation, depending on the level of customization or influence your organization requires.

While open-source, Zabbix has the feel and depth of a commercial product backed by years of development and a vibrant global partner ecosystem. Zabbix has evolved significantly over time, especially in usability. The development pace has remained strong, with new features landing every six months and LTS versions every 18 months. Early versions were seen as powerful but clunky.

Starting with the 5.0 LTS release and continuing through the 6.x versions, Zabbix introduced sleek, modern dashboards, native HA setups, external secret storage, and a tighter focus on cloud and container monitoring. This addresses a key concern for DevOps teams and cloud-native infrastructures.

In recent updates, Zabbix 7.2.x introduced several enhancements that benefit network administrators. The update brings advanced data visualization tools, sparkline charts across various widgets, native NVIDIA GPU monitoring enhanced with NETCONF support via SSH subsystems, and improvements in VMware monitoring, such as standalone hypervisor templates and maintenance mode detection.

Zabbix Key Features:

• Metric Collection: Zabbix can gather data from virtually any device or service using protocols like SNMP, IPMI, JMX, or its lightweight Zabbix Agent.
• Problem Detection: Uses flexible trigger logic to identify anomalies, performance degradation, or failures automatically. You can define thresholds and conditions or use prebuilt templates.
• Intelligent Alerting: Once an issue is detected, Zabbix can instantly notify you via email, SMS, Telegram, Slack, or integrated ITSM systems.
• Data Visualization: Zabbix includes built-in tools to visualize performance trends through dashboards, graphs, heat maps, and topology maps.
• Out-of-the-Box Templates: Zabbix’s extensive collection of pre-configured templates for common platforms and devices makes getting started easier.
• Distributed Monitoring Architecture: Zabbix’s distributed model lets you deploy proxies or agents in multiple locations and monitor everything from a centralized web interface.
• Scalability & High Availability: Zabbix has matured into a tool that supports enterprise-scale deployments. Features like native high availability (HA), external secret vaults, and support for millions of metrics per second make it suitable for mission-critical environments and large service providers.

Unique Buying Proposition

Zabbix’s most significant selling point is that it’s 100% open-source yet enterprise-ready. What you see is what you get. That makes it especially attractive for mid-sized and large organizations trying to control software spending without compromising reliability or capability. With no licensing costs and support for unlimited devices, it can grow with your infrastructure without draining your IT budget.

Why do we recommend Zabbix?

Choose Zabbix if you’re managing a complex infrastructure and want deep visibility without buying into an expensive SaaS or commercial monitoring solution. We recommend it because it is mature, scalable, well-documented, has a large community, and offers optional commercial support through Zabbix LLC or its partners. I’ve seen it successfully deployed in everything from small office setups to global data centers. It’s flexible enough to fit into most environments.

Who is Zabbix recommended for?

Zabbix is best suited for network admins, sysadmins, and IT teams in MSPs and mid-to-large enterprises that need a centralized, scalable solution for monitoring hybrid or on-prem infrastructure.

Overall, Zabbix is incredibly flexible with its open-source networking monitoring options and is supported by a large dedicated community that have continuously improved the platform over the years.

2. Prometheus + Grafana

Best For: Network managers and DevOps teams in MSPs and mid-to-large organizations

Price: Free and open-source

Prometheus is a tool for event monitoring and alerting. It acts as your metric collector and time-series database (which means each metric is tracked over time), using a powerful pull-based model to gather real-time data from various sources. Grafana, on the other hand, connects to Prometheus as a data source and provides you with a modern UI to build interactive dashboards for visualization.

Prometheus and Grafana give you a modern, cloud-ready monitoring solution. Together, they let you track real-time metrics, set up accurate alerts, and visualize trends across your infrastructure. Here’s how they fit together:

• Prometheus scrapes metrics from your systems and stores them.
• Grafana reads metrics from Prometheus using PromQL queries.
• You visualize those metrics in Grafana dashboards.
• Alerting can be handled by either Prometheus (via Alertmanager) or Grafana’s own alert engine.

Both Prometheus and Grafana are 100% open-source and community-driven.

Prometheus + Grafana Key Features:

• Pull-Based Time-Series Data Collection: Prometheus collects metrics from exporters on a defined schedule so you can understand how your systems behave over time.
• PromQL Query Language: This lets you write expressive, powerful queries to slice, dice, and aggregate metrics across dimensions.
• Rich Dashboards with Grafana: Grafana provides a flexible, interactive interface to visualize Prometheus metrics. You can create detailed dashboards with graphs, heatmaps, tables, and filters for real-time monitoring and executive overviews.
• Custom Dashboards with Grafana: Build highly visual, interactive dashboards that help you understand high-level trends and low-level events.
• Precise Alerting with Alertmanager: Define alert rules in PromQL and route notifications to Slack, email, PagerDuty, and more.
• Native Kubernetes Integration: Prometheus integrates with Kubernetes and other cloud and container managers to continuously discover and monitor your services.
• Lightweight and Easy to Deploy: Prometheus is a self-contained Go binary that requires no external database or runtime dependencies. Grafana also runs standalone, making the stack fast to deploy and easy to manage.

Unique Buying Proposition

The real power of Prometheus lies in its flexibility and visibility at scale. Unlike monolithic tools, you’re not locked into one way of monitoring. You get to design your observability stack around how your systems work, not the other way around. And with Grafana sitting on top, you can deliver highly tailored visualizations to both technical and business stakeholders. This combination hits a sweet spot between open-source freedom and enterprise-grade capabilities.

Why do we recommend Prometheus + Grafana?

We recommend Prometheus and Grafana because they offer a powerful, flexible, and cost-effective monitoring solution that provides complete real-time visibility into your systems. This combo benefits organizations working with cloud, containers, or dynamic infrastructure.

Its modular design allows you to build a monitoring solution that scales with your team’s skill set. You can start small with core Prometheus and a few exporters, then gradually layer in Alertmanager, remote storage, service discovery, or even advanced Grafana dashboards. Unlike some “black-box” commercial tools, this stack gives you total control and visibility.

Who is Prometheus + Grafana recommended for?

Prometheus + Grafana is an excellent fit if you’re an IT or DevOps team managing modern, dynamic infrastructure, especially Kubernetes, or a network admin who wants deep visibility into system metrics with the ability to customize alert logic, or an MSP that needs scalable, multi-client dashboarding and alerting.

3. LibreNMS

Best For: Network admins and IT teams in MSPs, SMBs, universities, ISPs

Price: Free and open-source

LibreNMS is an open-source network monitoring system built primarily to monitor network devices using SNMP. As a network administrator, you’ll appreciate that it’s designed to automatically discover and monitor routers, switches, servers, firewalls, and other network equipment without requiring manual configuration of each device. Once set up, LibreNMS continuously polls your devices to collect performance metrics, such as interface traffic, CPU load, memory usage, and port status, and displays them in graphs and dashboards.

What makes LibreNMS practical for daily operations is its SNMP-based auto-discovery combined with customizable alerting. It doesn’t just collect data; it actively notifies you when thresholds are crossed or outages occur. It supports distributed polling, too. So if you manage a large or multi-site network, you can scale it horizontally.

LibreNMS has really come a long way from its early fork of Observium. It inherited the SNMP-first mindset and added enhanced alerting, APIs, automation hooks, and a more user-friendly UI. Over the past few years, the dev team has significantly improved performance, LDAP support, and integrations. The development team made these improvements in response to real-world user needs, rather than chasing features for their own sake.

LibreNMS Key Features:

• Automatic Discovery: LibreNMS can automatically scan and map your entire network using a combination of protocols, such as CDP, LLDP, FDP, OSPF, BGP, SNMP, and ARP.
• Customizable Alerting: The alerting system is highly flexible and customizable. You can choose how and where you receive notifications, such as via email, IRC, Slack, or other channels.
• API Access: LibreNMS offers a comprehensive API that allows you to interact with your monitoring data-pull graphs, automate device management, or integrate with other systems as part of your workflow.
• Billing System: LibreNMS can generate bandwidth billing reports based on usage or total transfer per port.
• Distributed Polling: For larger or more complex networks, LibreNMS distributed polling allows you to scale horizontally by adding additional pollers to handle data collection across multiple sites or regions.
• Native iPhone App: The LibreNMS native iOS app gives you access to core functionality on the go, so you can monitor your network from anywhere.
• Native Android App: There’s also a native Android app that gives Android users the same mobile access to key features, alerts, and system status for convenient, mobile-friendly monitoring.

Unique Buying Proposition

LibreNMS combines ease of use with extensibility. You can deploy it quickly and see real value within hours, not days or weeks. Unlike Prometheus or Zabbix, LibreNMS relies heavily on traditional SNMP, which is still the dominant protocol in many networking environments.

It will significantly benefit organizations monitoring switches, routers, or firewalls from Cisco, Juniper, MikroTik, or Ubiquiti. It’s also community-driven yet actively maintained, so you get the benefits of open source without being left in the dark regarding updates or support.

Why do we recommend LibreNMS?

We recommend LibreNMS if your primary focus is network visibility, especially Layer 2/3 devices, rather than deep application monitoring. It gives you a clear view of what’s on your network, what’s working, and what’s not.

Alerting works well, the UI is fast and intuitive, and with features like oxidized integration for config backups and a decent REST API, it fits nicely into broader network ops workflows. It’s especially great if you’re replacing or moving away from legacy tools like MRTG, Cacti, or Observium (from which LibreNMS was originally forked).

Who is LibreNMS recommend for?

LibreNMS is best suited for network administrators and IT teams in SMBs, universities, ISPs, and enterprises that need strong visibility into network gear, as well as MSPs managing multiple clients or sites.

4. Icinga

Best For: Mid-size to enterprise IT teams, MSPs, and large institutions, DevOps and sysadmin teams.

Price: Free and open-source

Icinga is an open-source network and infrastructure monitoring platform designed to give you deep visibility into your entire IT environment, from servers and switches to services and applications. Icinga works by actively checking the availability and performance of your devices and services, typically through protocols such as ICMP (ping), SNMP, SSH, and HTTP. It uses a plugin-based architecture, so you can customize what you monitor and how.

Icinga also includes a powerful web interface, a REST API, and the Director module, which helps you automate configuration. It was initially forked from Nagios in 2009 but has grown far beyond its roots. The Nagios heritage gave Icinga credibility and compatibility early on, but Icinga has carved out its own identity by addressing many of the limitations that Nagios never resolved. Its modular design, high availability options, and multi-zone architecture give you the scalability and control you need.

Icinga Key Features:

• Infrastructure Monitoring: Monitor servers, network devices, services, databases, cloud platforms, and more from a central dashboard.
• Automation & Director Module: You can import data from CMDBs or directories and scale quickly without manual overhead.
• Cloud Monitoring: Stay independent of cloud vendors by using Icinga to monitor AWS, Azure, or hybrid cloud environments on your terms.
• Metrics & Logs: Pull metrics from Prometheus or Graphite and integrate logs.
• Analytics & Reporting: Create visual dashboards, generate SLA reports, and pinpoint trends or anomalies across your infrastructure.
• Alerting: Customize notifications to reach you through Slack, email, SMS, or other channels only when it matters.

Unique Buying Proposition

Icinga is flexible enough to fit different environments, scales well for enterprise setups, and gives you complete visibility across your stack. Unlike many open-source tools, it comes with a clean, modern web interface, solid documentation, and many integrations that help it play nicely with the rest of your systems.

From a network manager’s or IT decision-maker’s perspective, this value proposition speaks directly to operational efficiency, long-term scalability, and ease of adoption. Without rigid licensing models, you get complete control over how your infrastructure is monitored, from on-prem switches and routers to hybrid cloud environments.

Why do we recommend Icinga?

We recommend Icinga because it balances enterprise-grade monitoring and open-source flexibility. From a buyer’s standpoint, Icinga delivers if you’re looking for a tool that can handle everything from basic device checks to complex hybrid cloud environments.

It offers full-stack visibility, customizable alerting, modern dashboards, and deep automation options. Its REST API, Director module, and integration ecosystem add to its appeal in DevOps pipelines and traditional IT setups.

Who is Icinga recommended for?

Icinga is an excellent fit for mid-size to enterprise IT teams, MSPs and large institutions, DevOps and sysadmin teams, and anyone needing a modern replacement for Nagios that builds on familiar concepts but adds better usability and cloud-readiness.

5. Netdata

Best For: Network admins, IT ops teams, SMBs, and enterprises that value real-time visibility

Price: Free and open-source

Netdata collects real-time metrics, such as CPU usage, disk activity, bandwidth usage, website visits, etc., and then displays them in live, easy-to-interpret charts. It consists of a daemon that, when executed, collects and displays information in real time. You can run it on any Linux system, embedded Linux devices, PCs, and servers.

Based on our research, Netdata’s approach differs from other monitoring tools discussed due to its fast, zero-latency monitoring and AI-driven insights that help you catch issues before they become outages. Unlike some traditional monitoring tools that sample data or centralize it (which adds lag and infrastructure costs), Netdata takes a distributed approach. It keeps your data at the edge, where it’s generated, for better performance, tighter control, and actual data sovereignty.

Netdata Key Features:

• Rapid Setup & Full Automation: Install Netdata with a single command and get up and running in seconds.
• Open-Source Integrations: Netdata supports over 800 plugins for monitoring systems, containers, databases, apps, and more, using open standards.
• Fast, Real-Time Monitoring with Low Latency: Monitor every metric and second with zero sampling and ultra-low latency.
• Powerful Dashboards & Visualizations: Its intuitive UI lets you filter, pivot, and explore metrics without writing queries.
• Intelligent Alerts & Notifications: Netdata includes hundreds of preconfigured alerts and supports real-time notifications, so you’re warned about issues before they escalate.
• AI-Powered Anomaly Detection: Netdata uses edge-based, unsupervised machine learning to detect anomalies in every metric.
• Scalable and Flexible Infrastructure Monitoring: Netdata scales with you, and supports high retention and performance with minimal overhead.

Unique Buying Proposition

Netdata offers real-time, full-spectrum monitoring with zero sampling, ultra-low latency, and complete edge-based data processing, as confirmed by its official documentation, architecture design, and extensive user feedback across technical forums. From a buyer’s standpoint, this translates to faster detection, fewer false positives, reduced downtime, and significant cost savings on infrastructure and storage. It’s one of the few platforms that puts performance and data ownership in your hands without extra licenses or lock-in.

Why do we recommend Netdata?

From a practical perspective, Netdata solves a central pain point: traditional tools either miss spikes due to sampling or overwhelm your central servers. Netdata gives you the raw truth of what’s happening on your network. It’s suitable for teams that need to move fast, scale without friction, and maintain control over their data.

Who is Netdata recommended for?

Netdata is best suited for network admins and IT ops teams in fast-moving environments; SMBs and enterprises that value real-time visibility and cost-efficiency; and B2B buyers seeking modern monitoring that scales without ballooning TCO.

Which open-source networking monitoring tool is right for you?

While there are quite a few tools to choose from, how do you know which one is right for you? Our top choice is Zabbix due to its ease of use and simple integrations into other platforms.

While some tools like Prometheus offer highly detailed graphing and query analysis, these features sometimes create complexity that keeps businesses away. Zabbix offers numerous out-of-the-box tools that allow you to get the platform working for you without having to spend a day setting it up.

Broader B2B Software Selection Methodology

We aimed to identify the best tools based on a balanced, real-world framework. We examined both technical and practical aspects. Each tool was evaluated on seven core criteria: Features, scalability, ease of use, extensibility, community support, performance, and active development.

Each tool was scored on these factors and weighted to reflect real-world IT needs, from enterprise environments to cloud-native operations. This allowed us to objectively assess each tool’s strengths and trade-offs, rather than relying on popularity or anecdotal evidence alone.

Zabbix ranked highest due to its comprehensive feature set and scalability. Prometheus follows closely and excels in cloud-native and containerized environments with its flexibility and visualization power. LibreNMS stood out for network-focused teams thanks to its SNMP-based auto-discovery and ease of use. Tools like Icinga and Netdata, and by extension Nagios, and OpenNMS filled specialized roles.

We clearly explain our evaluation methodology so you can confidently align your selection with your network monitoring needs. We believe the best choice ultimately depends on your environment and goals.

Check out our detailed B2B software methodology page to learn more.

Open source network monitoring FAQs