segment · monitoring
Network monitoring software
Network monitoring software continuously watches the availability and performance of servers, network devices and applications, and alerts you before small problems become outages. This page compares open-source and commercial monitoring platforms by license, scale and monitoring approach, with a link to each vendor’s official site.
the shortlist
9 network monitoring tools compared
Ordering is by category relevance, not by any commercial arrangement — see our methodology. 5 of 9 are open-source.
| Tool | Vendor | License | Best for | |
|---|---|---|---|---|
| PRTG Network Monitor | Paessler | Commercial | All-in-one infrastructure monitoring with sensor-based licensing and a free tier. | Details → |
| Zabbix | Zabbix | Open source (GPLv2) | Open-source enterprise monitoring for networks, servers, cloud and applications. | Details → |
| Nagios Core | Nagios Enterprises | Open source (GPLv2) | Long-standing open-source monitoring engine for hosts, services and network devices. | Details → |
| ManageEngine OpManager | Zoho / ManageEngine | Commercial | Network and server monitoring with fault management and reporting. | Details → |
| Auvik | Auvik Networks | Commercial | Cloud-based network monitoring and management for IT teams and MSPs. | Details → |
| SolarWinds NPM | SolarWinds | Commercial | Enterprise network performance monitoring with topology and alerting. | Details → |
| LibreNMS | LibreNMS Community | Open source (GPLv3) | Open-source auto-discovering network monitoring system with SNMP support and alerting. | Details → |
| Icinga | Icinga GmbH | Open source (GPLv2) | Open-source monitoring platform for hosts, services and network infrastructure, forked from Nagios. | Details → |
| Checkmk | Checkmk GmbH | Open source (GPLv2) | Infrastructure and network monitoring with an open-source Raw Edition and commercial editions. | Details → |
buyer's checklist
What to look for
- Agent vs agentless
- Agentless tools poll devices over SNMP, WMI or SSH; agent-based tools install a collector for deeper metrics. Many combine both.
- Scale
- A handful of servers has different needs than thousands of nodes across sites. Check tested device counts and distributed polling.
- Alerting
- Look at notification channels (email, SMS, chat, webhooks), escalation and dependency-aware alerting to cut noise.
- Licensing model
- Pricing is charged per sensor, per device or per node depending on the vendor — this changes total cost sharply by environment.
- Open-source vs commercial
- Open-source platforms are free to run but need more setup; commercial tools add support, packaged dashboards and easier onboarding.
free & open-source
Free & open-source network monitoring tools
Zabbix, Nagios Core, LibreNMS, Icinga and Checkmk (Raw Edition) are open-source and free to self-host. They scale well but expect more configuration than a packaged commercial product.
- ZabbixGPLv2
- Nagios CoreGPLv2
- LibreNMSGPLv3
- IcingaGPLv2
- CheckmkGPLv2
FAQ
Common questions
What is network monitoring software?
It is software that continuously checks whether servers, network devices and services are up and performing within expected thresholds, then raises alerts when something degrades or fails so teams can react before users are affected.
What is the difference between agent-based and agentless monitoring?
Agentless monitoring collects data by polling devices over standard protocols such as SNMP, WMI or SSH, so nothing is installed on the target. Agent-based monitoring runs a small collector on each host for deeper, more frequent metrics. Many platforms support both.
Which network monitoring tools are open source and free?
Zabbix, Nagios Core, LibreNMS, Icinga and Checkmk Raw Edition are open-source and free to self-host. They are widely used in production; the trade-off is more setup and maintenance than a commercial platform.
What is SNMP monitoring?
SNMP (Simple Network Management Protocol) lets monitoring tools query network devices such as switches, routers and printers for status and performance counters without installing an agent. Most monitoring platforms support SNMP polling and traps.