ntopng has the ability to create alerts for flows, hosts, and other network elements. Alerts for flows and hosts are created inside the C++ core of ntopng for performance. This section describes how to create alerts for hosts and flows. Alerts for other network elements are created by means of plugins (Plugin Structure).
Alerts are created inside callbacks. This section starts with a description of callbacks, and then moves to the alerts. The interplay between alerts and callbacks is presented, along with examples with the aim of giving a comprehensive overview of all the components at play. The section ends with handy checklists that can be used as reference when developing alerts.