CSF/LFD Firewall is installed by default on all CWP servers.
Here you can find useful commands you can use from your terminal.
To get the list of all options please use this commands

csf --help
man csf

Configuration location is in the folder /etc/csf/
Main configuration file: /etc/csf/csf.conf

Enable CSF Firewall

csf -e

Disable CSF Firewall

csf -x

Restart CSF Firewall (iptables rules)

csf -r

Restart CSF/LFD Firewall (iptables rules and LFD service)

csf -ra

Restart LFD only

service lfd restart

Check blocked IP reason (replace IP with the IP address)

csf -g IP
grep "IP" /var/log/lfd.log

Block IP (permanently)

csf -d IP

Block IP (temporarily for 24 hours, define in seconds)

csf -td IP 86400

Unblock IP

csf -dr IP

Whitelist IP (allow access to all ports)

csf -a IP

Whitelist IP range /24 (allow access to all ports)

csf -a

Whitelist (temporarily) IP range /24 for 24 hours (allow access to all ports, define in seconds)

csf -ta 86400

Remove all temporary IP blocks

csf -tf

Remove all permanent IP blocks

csf -df

....and many others