Zabbix

Yes, Zabbix is released under the GPL v2 license, meaning it is entirely free to use with no per-node or per-metric licensing fees regardless of scale. Unlike commercial tools like SolarWinds or Datadog, Zabbix does not impose usage limits, which makes it attractive for large infrastructure deployments.

While both are open-source monitoring platforms, Zabbix offers built-in data collection, visualization, and auto-discovery features out of the box, whereas Nagios relies more heavily on external plugins and add-ons for similar functionality. Zabbix also stores historical metrics in its own database, while Nagios typically requires additional tools like Graphite or InfluxDB for long-term graphing.

Zabbix supports PostgreSQL, MySQL and MariaDB, Oracle, and TimescaleDB for time-series data optimization. PostgreSQL with TimescaleDB is often recommended for large deployments because it handles high-volume metric ingestion more efficiently than standard MySQL.

Yes, Zabbix includes native SNMP polling and trapping support, allowing it to monitor network devices from vendors like Cisco, Juniper, and Arista. You can use Zabbix's built-in SNMP template library or import custom MIBs for vendor-specific metrics.