Prosody doesn't write IP addresses to its log file by default for privacy reasons (unless debug logging is enabled).
This module enables logging of the IP address in a failed authentication attempt so that those trying to break into accounts for example can be blocked.
fail2ban is a utility for monitoring log files and automatically blocking "bad" IP addresses at the firewall level.
With this module enabled in Prosody you can use the following example configuration for fail2ban:
# /etc/fail2ban/filter.d/prosody-auth.conf # Fail2Ban configuration file for prosody authentication [Definition] failregex = Failed authentication attempt \(not-authorized\) for user .* from IP: <HOST> ignoreregex =
And at the appropriate place (usually the bottom) of /etc/fail2ban/jail.conf add these lines:
[prosody] enabled = true port = 5222 filter = prosody-auth logpath = /var/log/prosody/prosody*.log maxretry = 6