iptables -t nat -L -n
FW_IP="122.116.232.30"
iptables -t nat -A POSTROUTING -o eth0 -s 192.168.0.163 -j SNAT --to-source $FW_IP
iptables -t nat -A PREROUTING -i eth0 -p tcp -d $FW_IP --dport 22 -j DNAT --to-destination 192.168.0.163:22
iptables -t nat -A PREROUTING -i eth0 -p tcp -d $FW_IP --dport 30021 -j DNAT --to-destination 192.168.0.163:21
iptables -t nat -A PREROUTING -i eth0 -p tcp -d $FW_IP --dport 30022 -j DNAT --to-destination 192.168.0.163:22
iptables -t nat -A PREROUTING -i eth0 -p tcp -d $FW_IP --dport 30080 -j DNAT --to-destination 192.168.0.163:80
iptables -t nat -A PREROUTING -i eth0 -p tcp -d $FW_IP --dport 30443 -j DNAT --to-destination 192.168.0.163:443
iptables -t nat -A PREROUTING -i eth0 -p tcp -d $FW_IP --dport 30025 -j DNAT --to-destination 192.168.0.163:25
iptables -t nat -A PREROUTING -i eth0 -p tcp -d $FW_IP --dport 30110 -j DNAT --to-destination 192.168.0.163:110