My situation is as follows:

My main-host is connected to a Linux host with two nic's - NAT and firewall to the external network - this nic's to the external net is connected to my Fritz!Box, that is configured to use UPnP. But all I get is an "Internal Server Error".

What I tried so far: I configured the Fritz!Box to use dedicated ports to the host in the middle. I confugured the host in the middle to work as a router from outside to inside. Once upon a time the config worked, but with upgrading my system I lost that config.

Please can someone help me? I want to share the files that I download with other users.

I use KTorrent 4.1.0

biker wrote:My situation is as follows:

My main-host is connected to a Linux host with two nic's - NAT and firewall to the external network - this nic's to the external net is connected to my Fritz!Box, that is configured to use UPnP. But all I get is an "Internal Server Error".

What I tried so far: I configured the Fritz!Box to use dedicated ports to the host in the middle. I confugured the host in the middle to work as a router from outside to inside. Once upon a time the config worked, but with upgrading my system I lost that config.

Does it work when you connect directly to the Fritzbox ?

If you are behind two NAT's, then the UPnP plugin will not really work. It is probably better to configure the port forwarding rules your self on the Fritzbox and the host in the middle.

The FritzBox is too far away.
Which ports should I configure?
6991 and 4444(that's what I tried), or any others.
UDP or TCP?

There are several ports:
- Normal bittorrent port (Network Settings -> Port), this is TCP and UDP (if µTP is enabled)
- Port for UDP tracker communication (Network Settings -> UDP tracker port), this is obviously UDP.
- The DHT port (Bittorrent Settings -> UDP port for DHT communications), also UDP.

Sorry for my late reply, but my mother is really sick.
I will try to configure my FritzBox and the host between.

Thanks a lot.