ConfigServer Firewall, also known as CSF, is a firewall configuration script created to provide better security for your server while giving you an advanced, easy to use interface for managing firewall settings. ... ConfigServer Firewall also comes with a service called Login Failure Daemon, or LFD.
Run the following commands to install CSF:
cd /usr/src rm -fv csf.tgz wget https://download.configserver.com/csf.tgz tar -xzf csf.tgz cd csf sh install.sh