## ssh - port 22
iptables -t nat -A prerouting_rule -i $WAN -p udp --dport 22 -j DNAT --to 10.0.0.51
iptables -t nat -A prerouting_rule -i $WAN -p tcp --dport 22 -j DNAT --to 10.0.0.51
iptables -A forwarding_rule -i $WAN -p tcp --dport 22 -d 10.0.0.51 -j ACCEPT
iptables -A forwarding_rule -i $WAN -p udp --dport 22 -d 10.0.0.51 -j ACCEPT