SSH brute force protection

As for protecting your site against brute force attacks, the first option is to use SSH keys (and disable password authentication).

Open terminal and follow the lines;

sudo vi /etc/ssh/sshd_config

ChallengeResponseAuthentication no
PasswordAuthentication no

service sshd restart

SSH Failed Login Attemps

You can see the last failed login attemps

tail -f /var/log/secure