Fail2ban lee los logs (por ejemplo) /var/log/pwdfail o /var/log/apache/error_log y veta todas aquellas ips que fallan un determinado número de veces. Este veto se realiza actualizando el firewall (tipicamente iptables).

wget http://superb-west.dl.sourceforge.net/sourceforge/fail2ban/fail2ban-0.8.1.tar.bz2
tar -xjvf fail2ban-0.8.1.tar.bz2
cd fail2ban-0.8.1
python setup.py install

fail2ban-client start
fail2ban-server start

fail2ban-client start
fail2ban-server startfail2ban-client start
fail2ban-server start

fail2ban-client start
fail2ban-server start