Alternatives to Nagios Core
Monitor hosts and services with a configurable alerting engine. The listings below can replace it for an important use case. Each note says what changes if you switch.
The original
Nagios Core
Monitor hosts and services with a configurable alerting engine.
Replacements
Listings that take over the same core job as Nagios Core.
Icinga 2
Monitor infrastructure availability with a configurable checking and alerting system.
Icinga 2 runs checks and notifications with distributed monitoring support under GPL-3.0, though a complete deployment involves optional web-interface components.
Nagios XI
Commercial self-hosted edition of Nagios with a web-based setup wizard.
Nagios XI adds a web setup wizard and dashboards on top of Nagios Core, but is paid and proprietary with per-node licensing.
Zabbix
Enterprise-scale open-source monitoring for networks and applications.
Zabbix offers enterprise-scale monitoring with proxies and a large template library under AGPL-3.0, with an extensive configuration learning curve.
Checkmk
Hybrid open-source and commercial monitoring with agent-based and SNMP auto-discovery.
Checkmk adds agent-based and SNMP auto-discovery to cut manual setup, but advanced features and scaling are in paid commercial editions.
Centreon
French enterprise network and IT monitoring platform with business activity dashboards.
Centreon adds business activity dashboards linking infrastructure to business impact, with the full feature set split across free and paid editions.
NetXMS
Monitor network devices, servers and infrastructure through a central platform.
NetXMS monitors network devices, servers and infrastructure through a central platform, with enterprise services under separate terms.
OpenNMS
Carrier-grade open-source network monitoring platform with event correlation.
OpenNMS adds carrier-grade event correlation and Grafana integration, though its complexity suits large networks more than small setups.
PRTG Network Monitor
Sensor-based network monitoring, free for the first 100 sensors.
PRTG configures autodiscovery, maps and alerting through one interface, free for 100 sensors, but is closed source and runs on Windows servers only.
Similar software
Related functionality, not a direct replacement.
LibreNMS
Discover and monitor network equipment from a central server.
Prometheus
Metrics database that scrapes targets and evaluates alerting rules.
Prometheus Alertmanager
A server that deduplicates, groups and routes alerts from Prometheus to email, PagerDuty and other receivers.
Netdata
Per-second metrics for a machine with no configuration, and charts that appear the moment you install it.
Uptime Kuma
A self-hosted uptime monitor that pings your sites and services and tells you the moment one stops answering.
