FEATURE Client Server
Until version 0.6, Fail2ban daemon is simply an application running in background and detached from any terminal. It do not allow reconfiguration of the daemon while it runs or any quite of communication with it.
Fail2ban is split into two parts:
The Server part monitors log file(s) and executes actions when a host has to be banned. The configuration of the Server is done by the Client which take care of reading configuration files. Communication between the Client and the Server is done through a socket. A protocol is defined. This allows dynamic reconfiguration of the Server and communication with it in order to retrieves, per example, statistics.