masquerade

This guide explains how to use IP Forwarding and iptables NAT to redirect all incoming traffic from a Linux server to a 4iProto destination server. This scenario is used for Full Traffic Forwarding, Transparent Proxy, and Gateway Relay.

• Linux operating system
• Root access
• iptables installed and active
• Valid 4iProto server IP
• Basic understanding of NAT, DNAT, SNAT, Routing

echo "net.ipv4.ip_forward=1" >> /etc/sysctl.conf
sysctl -p

iptables -t nat -A PREROUTING -p tcp --dport 22 -j DNAT --to-destination IRAN_IP

iptables -t nat -A PREROUTING -j DNAT --to-destination 4iProto_IP

iptables -t nat -A POSTROUTING -j MASQUERADE

• The SSH port rule must be applied before the general PREROUTING rule
• Ensure alternative SSH access before applying rules
• Adjust firewall settings if using firewalld or ufw