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At my home I have a Linux server (it's only job is NAT, DHCP, and DNS) with Ubuntu 10.10 Server 64-bit.

I have webmin installed on the server too, but I do know my way around a command line quite well, so I can do anything suggested. I have a game server in my NAT, which hosts on port 28000 UDP, and it's IP address is (Internal).

I setup the port forwarding under Webmin as I do not understand how to use iptables via command line.

When someone attempts to connect to the game server via the Internet, they cannot connect. I took a look at wireshark on the external computer and I see ICMP packets that it needs to connect to the game server ( The entry says "Destination Unreachable (Port Unreachable)"

I took a look at the packet and noticed it says:

User Datagram Protocol, Src Port: nxlmd (28000), Dst Port: 45282 (45282)

The destination port occasionally changes after a different person connects, so I cannot just forward the port.

Bottom line, is there any way I can have it so packets that should go to my internal game server (, do go to my internal game server?

Thank you very much in advance!

Any ideas? Really need to get this working.

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This is why router centric distributions were created. They are easy to install and manage without the learning curve of linux networking. If this is the machines only job, I recommend IPCOP or better yet PFSENSE as a replacement. And you will get much more out of those distros than you would ubuntu if you don't know linux-networking and services.

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