iptables local forwarding game server

[aequitas]

I got myself a openttd gameserver running at a spare powermac at home. My server routes it nicely to the internet so people can join. Only i can't join from the inside with the external ip adres. So i have to add the local ip adres manually every time.

I tried using the following iptables rule:

# forwaring openttd
iptables -A PREROUTING -t nat --protocol tcp -i eth0 --destination-port 3979 -j DNAT --to 192.168.0.5
iptables -A PREROUTING -t nat --protocol udp -i eth0 --destination-port 3979 -j DNAT --to 192.168.0.5

eth0 is the local networking interface. 192.168.0.5 is the game server.

The game uses port 3979 for connections and uses udp and tcp.

When i check the server logs my desktop from which i try to connect doesn't show up.

Am i doing something wrong here with the iptables? Or could it be that the game switches to a different port after connecting a client?
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