ConfigServer (CSF) is advanced firewall and free available for Linux and debian based distributions. In latest versoin of CentOs 7 , RHEL 7 , CloudLinux 7 servers require that use the firewalld daemon but we can use iptables command for firewall and In WHM CSF
Firewalld & Iptables [box] The most common network filtering programs is iptables. In latest Red Hat Enterprise and other linux based Operating system another firewall is available named as Firewalld . Iptables was the main method for network packet filtering program in earlier or old Red Hat