1. Create new conf file as, /etc/sysctl.d/openvpn.conf sudo nano /etc/sysctl.d/openvpn.conf 2. add content into it as, net.ipv4.ip_forward = 1 Now time to add CSF firewall rules. 3. Create new SH file inside CSF folder, sudo nano /etc/csf/csfpost.sh 4. Add below contents into it as, iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE iptables -A INPUT -i tun+ -j ACCEPT iptables -A FORWARD -i tun+ -j ACCEPT iptables -A FORWARD -o tun0 -j ACCEPT iptables -A FORWARD -i tun+ -o eth0 -m state