fail2ban is a simple daemon (written in Python, BTW) which monitors your Linux server logs and is able to prevent bruteforce attacks by adding bad IP addresses to iptables. This is a simple self reminder on how to setup it.
yum install fail2ban
If you want fail2ban to only notify you (and not add them to iptables) modify the configuratio files this way:
action = sendmail-whois[name=SSH, email@example.com, firstname.lastname@example.org]
It would be wise to add your IP addresses to be ignored:
ignoreip = 127.0.0.1/8
service fail2ban start
Enable auto start:
chkconfig fail2ban on
Now if somebody tries to brueforce your SSH you’ll get a mail.