wiki.podrabsky.cz

iptables -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -i venkovni_sitovka -p TCP --dport 3389 -j ACCEPT
iptables -t nat -A PREROUTING -i venkovni_sitovka -p TCP --dport 3389 -j DNAT --to server_na_vnitrni_siti:3389

Port forwarding
iptables -t nat -A PREROUTING -p tcp –-dport 10022 \
-j DNAT –-to-destination 10.0.0.10:22

# Port Forwarding is enabled, so accept forwarded traffic
$IPT -A FORWARD -p udp -i $INET_IFACE --destination-port 3389 \
--destination 192.168.1.103 -j ACCEPT

$IPT -A FORWARD -p tcp -i $INET_IFACE --destination-port 3389 \
--destination 192.168.1.103 -j ACCEPT