In this example all incoming traffic on port 80 redirect to port 8123
iptables -t nat -I PREROUTING --src 0/0 --dst 192.168.1.5 -p tcp --dport 80 -j REDIRECT --to-ports 8123
Delete all existing rules
sudo iptables -F
In case of forwarding
sudo iptables -t nat -I PREROUTING --src 0/0 --dst 10.0.3.10 -p tcp --dport 63001 -j REDIRECT --to-ports 3306 sudo iptables -t nat -I PREROUTING --src 0/0 --dst 10.0.3.20 -p tcp --dport 63101 -j REDIRECT --to-ports 3306
sysctl net.ipv4.ip_forward=1 my_wan_ip=13.124.177.95 sudo iptables -t nat -A PREROUTING -p tcp -i ppp0 --dport 63001 -j DNAT --to-destination 10.0.3.10:3306 sudo iptables -A FORWARD -p tcp -d 10.0.3.10 --dport 3306 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT sudo iptables -A POSTROUTING -t nat -p tcp -m tcp -s 192.168.1.200 --sport 8080 -j SNAT --to-source $my_wan_ip sudo iptables -t nat -A PREROUTING -p tcp -i ppp0 --dport 63101 -j DNAT --to-destination 10.0.3.20:3306 sudo iptables -A FORWARD -p tcp -d 10.0.3.20 --dport 3306 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT sudo iptables -A POSTROUTING -t nat -p tcp -m tcp -s 192.168.1.200 --sport 8080 -j SNAT --to-source $my_wan_ip sudo iptables -A POSTROUTING -t nat -p tcp -m tcp -s 192.168.1.200 --sport 8080 -j SNAT --to-source $yours_wan_ip