Linux/CentOS 7

Firewall [1]

firewall-cmd --add-port=80/tcp --permanent
firewall-cmd --reload

EPEL

wget http://dl.fedoraproject.org/pub/epel/7/x86_64/e/epel-release-7-1.noarch.rpm
rpm -ivh epel-release-7-1.noarch.rpm

I think it is also in the 'extras' package too

fail2ban

Install #EPEL (I think it is also in the 'extras' package too)

Install fail2ban

yum install fail2ban

Copy default config to local config:

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

Modify local config:

vi /etc/fail2ban/jail.local
  [sshd]
  enabled  = true

Restart fail2ban

sudo service fail2ban restart

References:

• How To Protect SSH with fail2ban on CentOS 6 | DigitalOcean - https://www.digitalocean.com/community/tutorials/how-to-protect-ssh-with-fail2ban-on-centos-6