Fail2Ban scans log files like /var/log/pwdfail and bans IP that makes
too many password failures. It updates firewall rules to reject the
IP address. These rules can be defined by the user. Fail2Ban can read
multiple log files such as sshd, Apache web server, postfix and others.

To install the bash completion script, pass BASH_COMPLETION=yes to the
SlackBuild, for example

  BASH_COMPLETION=yes ./fail2ban.SlackBuild

See README.SBo for configuration and upgrade help.