You need to let your client access to every port at every IP, because you never know what port the other end is using.

Then, you should enable port forwarding in your router, and forward all TCP packets (UDP packets can be blocked) from port 6346 (or other, if you wish) to your PC port 6346 (the same port as in router). Without portforwarding you are unable to download from other firewalled users. Portforwarding will remove the Firewalled status from your client.