What is OpenNMS?

OpenNMS is an open-source network monitoring platform that helps you visualize and monitor everything on your local and distributed networks. OpenNMS offers comprehensive fault, performance, traffic monitoring, and alarm generation in one place. Highly customizable and scalable, OpenNMS integrates with your core business applications and workflows.

OpenNMS is available as two open source distributions.


Subscription service that provides access to an optimized and very stable version of OpenNMS that maximizes the platform’s value and minimizes the effort required to maintain it.

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Free, community-based, quick release distribution that contains all of the newest features developed for the platform.

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NEW Minion Virtual Appliance
The Minion Virtual Appliance is a virtual device that enables OpenNMS to collect data from hard-to access devices and services.

Full inventory management
Flexible provisioning system provides many ways to interoperate with configuration management systems.

Extensive data collection
Works with many industry-standard data collection protocols (14) with no need to write or maintain third-party plugins: SNMP, JSON, WinRM, XML, SQL, JMX, SFTP, FTP, JDBC, HTTP, HTTPS, VMware, WS-Management, Prometheus.

Robust traffic management
Supports four flow protocols (NetFlow v.5/9, IPFIX, sFlow). 300,000+ flows/sec. Deep-dive analysis, enterprise reporting.

Digital experience monitoring
Use the OpenNMS Minion to monitor a service’s latency and availability from different perspectives.

Robust configuration
Configure most features through the web UI or XML scripting, including thresholding, provisioning, event and flow management, service monitoring, and performance measurement.

Monitor hundreds of thousands of devices using a distributed and tiered system.

Enterprise reporting and visualization
Customizable dashboards that you can export as a PDF. Resource graphs, database reports, charts. Define and customize complex layered topologies to integrate topology maps into your service problem management workflow.

Product Documentation
Comprehensive Feature List
Frequently Asked Questions
OpenNMS Components in their ecosystem

OpenNMS Components

As the edges of enterprise networks expand, it can be difficult to keep pace with network monitoring requirements in a distributed environment. Highly distributed networks present issues such as security, privacy, reachability, and latency that make the monitoring, collection, and processing of large volumes of data difficult.

Read the whitepaper

Remote Monitoring with OpenNMS Minion

A Minion is an instance of the Karaf OSGi service that enables OpenNMS to monitor devices and services in locations that OpenNMS cannot reach. Minions communicate with these remote devices while OpenNMS performs coordination and task delegation.

Minions can operate behind a firewall and/or network address translation (NAT) as long as they can communicate with OpenNMS via ActiveMQ or Apache Kafka.

Simplify Minion management with the new Minion Virtual Appliance.

Scalability with OpenNMS Sentinel

Sentinel provides scalability for data processing, including flows, SNMP traps, syslog messages, and streaming telemetry. It also supports thresholding for streaming telemetry if you are using OpenNMS Newts. If you are using Minions or looking for scalable flow processing, you need Sentinel.

Sentinel is a Karaf container that handles data processing for OpenNMS and Minion, spawning new containers as necessary to deal with increased data volume.

Dashboard Visualization with OpenNMS Helm

Helm is an application for creating flexible dashboards to display and customize fault management and performance management data from OpenNMS Horizon and Meridian. Working with the Grafana analytics program, Helm allows you to view the data you want to see — alarms, outages, key performance indicators — in a way that best meets the needs of your workflow and staff.

Simply specify your datasource and the URL to your OpenNMS instance, and start creating dashboards to view and interact with your data in one place. Aggregate data from multiple OpenNMS instances for better monitoring of distributed deployments.

Alarm Triage with ALEC

The Architecture for Learning Enabled Correlation (ALEC) is a framework that uses artificial intelligence and machine learning to group related alarms so you can better manage the more complex situations they might represent.

ALEC uses temporal clustering techniques, machine learning algorithms and deep-learning technology with topology data to group related alarms into a high-level situation. ALEC can’t identify the cause of the problem, but it can indicate that alarms that happened at the same time on the same node might be related.

Streaming Telemetry and Flows

The OpenNMS project codenamed Drift supports streaming telemetry and forensics via flows. Parse and enrich incoming data with metadata like location, node, and service, then persist it to flow persistence storage.

Listens for Netflow, IPFIX, and sFlow packages.

Handles up to 300,000 flows per second.

Alternate Storage with Newts

Newts (New-Fangled Time Series Datastore) is a time series data store based on Apache Cassandra. Use it as an alternative persistence strategy instead of JRobin or RRDtool.


In addition to a robust REST API that allows you to easily get data in and out of OpenNMS, we integrate directly with many other systems and protocols (too many to list here).

These include, but are not limited to: 


E-mail, Slack, Mattermost, custom scripts


JIRA, Remedy, TSRM

BMP/BGP monitoring, Junos Telemetry Interface, NetFlow v5/9, sFlow, IPFIX, Cisco NX-OS Telemetry, OpenConfig Telemetry


Grafana, Kibana

Time Series Storage

RRD/JRobin, Newts


Created with the versioned OpenNMS Integration API (OIA). OIA is a stable interface developed to make it easier to write extensions and plugins for OpenNMS.

Learn More about OIA