NetXMS monitors networks and servers: it discovers what is on the network, draws the topology, polls devices over SNMP, collects metrics through its own agents, and raises alarms when something stops behaving. It is open source, developed by Raden Solutions, and the current version is 6.2.5 (September 2026).
One limit to know before you plan a deployment: the Windows server build is capped at 250 nodes without a licence. On Linux there is no such cap.
NetXMS at a glance
| Latest version | 6.2.5, released 14 September 2026 |
|---|---|
| Licence | Free, open source (GPL / LGPL) |
| Node limit | Windows server without a licence — 250 nodes. Linux — no limit |
| Server systems | Debian, Ubuntu LTS, RHEL 8 and 9, Windows 10/11 and Server 2016–2022, FreeBSD, Alpine, Raspbian |
| Minimum hardware | 1 GHz dual-core processor, 1 GB RAM, 1 GB disk |
| Database | Required: PostgreSQL (with TimescaleDB if you like), MySQL, MariaDB, Oracle or MS SQL Server |
| Management client | Separate application, needs Java 17 or newer |
What it does
- Automatic discovery of the network, with Layer 2 and Layer 3 topology maps built from LLDP, CDP and switch forwarding tables — you see what is plugged into which switch port.
- SNMP monitoring (v1, v2c and v3) including trap handling.
- Agents for Windows and Linux (x86, x86-64 and Arm) that collect far more than SNMP can, and can run your own checks.
- Business service modelling: define what “mail is working” means and get availability for the service, not just for individual hosts.
- Event correlation and alarms, so one failed switch does not generate fifty alerts.
- NXSL scripting for custom logic in checks, thresholds and automation.
- Dashboards, which can be shared through anonymous public links — handy for a wall display.
- Log viewer with multi-condition filters, plus OpenTelemetry log ingestion.
- Nagios-compatible plugins can be executed directly, so existing checks are reusable.
Installation in outline
- Click the Download button at the top of this page and unpack the archive, or use the vendor’s package repository.
- Install and prepare the database — PostgreSQL is the common choice. SQLite exists but is for testing only.
- Install the server, run the database initialisation, start the service.
- Install the management client on your own machine. It needs Java 17 or newer.
- Run discovery on your subnets, then deploy agents to the servers you care about most.
- Set thresholds only after a week of data — otherwise you will be tuning alerts instead of using them.
Where it fits
NetXMS suits a network with real infrastructure: managed switches, a few dozen servers, services that matter. The topology maps and business-service modelling are its strongest features, and both need a network complex enough to justify them.
For a handful of machines it is more than you need. For thousands of nodes with a team behind it, compare it against Zabbix, which has a larger community.
Recent changes worth knowing
- Native endpoint for AI assistant integration, replacing the separate Java component.
- Data collection through Nagios plugins via external checks.
- New drivers for Aruba CX and Cisco Catalyst 9800.
- Dashboards shareable through anonymous links.
- MQTT payloads are no longer truncated at 255 bytes.
Recently fixed problems
These are worth knowing if you are running an older build — all are fixed in current versions:
| Scheduled tasks never ran | Six-field cron expressions almost never fired on recurrent tasks. |
|---|---|
| SNMPv1 traps dropped by receivers | An encoding problem caused other tools to reject the traps. |
| Housekeeper stalled permanently | Happened when throttle watermarks were set to zero. |
| False memory alarms | Shared memory was counted twice when aggregating process memory usage. |
| Cisco topology incomplete | Broken where the forwarding table is read per VLAN. |
NetXMS vs. alternatives
| Tool | How it compares |
|---|---|
| Zabbix | Similar scope, much larger community and more ready-made templates; no node limit on any platform |
| Checkmk Raw | Free edition, quicker to set up, weaker network topology features |
| LibreNMS | SNMP and network-centric, auto-discovering; no agent framework of this depth |
| The Dude | Free and simple network maps, but discontinued by its vendor |
FAQ
Is NetXMS free?
Yes, it is open source. Commercial support contracts are sold separately, and agents for AIX, Solaris and HP-UX require one.
What is the 250-node limit?
The Windows server build stops at 250 nodes without a licence. If you expect to exceed that, run the server on Linux or buy a licence.
Does it need a database?
Yes. PostgreSQL, MySQL, MariaDB, Oracle or MS SQL Server. SQLite is only for testing.
Can it monitor without installing agents?
Yes, through SNMP, ICMP and service checks. Agents give much deeper data on servers.
Does the management client run on macOS?
It is a Java application and needs Java 17 or newer; there is also a web interface.
How is it different from Zabbix?
NetXMS is stronger on automatic Layer 2 topology and business-service modelling. Zabbix has a bigger community and more templates. Both are free.
