Fail2ban

Fail2ban scans log files and bans IPs that show the malicious signs -- too many password failures, seeking for exploits, etc. Generally Fail2Ban is then used to update firewall rules to reject the IP addresses for a specified amount of time, although any arbitrary other action (e.g. sending an email) could also be configured.

Enable the Service
Configure the service to start and run.
Maximum find time (findtime)
The moment that a given number of attempts is detected within a particular time.
Maximum retry number (maxretry)
The maximum of attempts before to be banned.
Maximum ban time (bantime)
Duration for IP to be banned for.
Recidive jail is perpetual
When an IP goes several time in jail, it goes to the recidive jail for a much longer time, if enable, it is perpetual
Allow bans on the LAN
By default all local network are whitelisted, enable to ban IP from the LAN.
IP Whitelisting
Ip listed here will be ignored by fail2ban (one IP per line).
Send email notifications
Enable to send administrative emails.
Notify jail start/stop events
Enable to send notification emails when a jail is started or stopped.
Email administrators
List of email addresses of administrators (one address per line).
List of Jails
By default all jails are made to start once the service is installed. Here you can desactivate each jail.