Fail2Ban is an SSH security program that blocks SSH brute force attempts on your server (as well as for many other services such as Apache, Nginx, webmail, etc). Installing it is quite simple and can be done in a few steps:

1. Login to your VPS as root

2. Run the following commands (and press y when asked):

yum install epel-release
yum install fail2ban

3. Now copy the configuration file template:

cp /etc/fail2ban/jail.conf /etc/fail2ban/jail.local

4. Start up the Fail2Ban service:

service fail2ban restart

5. The default settings are usually adequate, but you can further customize Fail2Ban by editing the config file located here:
/etc/fail2ban/jail.local
Make sure to restart the service after changing settings.