incoming packets not using my listening port

[bats059]

I have utorrent 2.03 set up to use a particular (fixed) listening port, but when I try to start a torrent, the incoming tcp packets are using a different port, hence they cannot get through my (mikrotik) firewall. I have the listening port forwarded to my network, but it's not much use if the incoming packets are using a different port.

Not only that, the various seeds i am using are each using different port numbers. I thought the idea of setting up a listening port was so that you would only need a single open port in the firewall?

I can get the torrents running if I open a hole for all tcp ports to the particular pc, but I am not too comfortable with that.

What am I missing here?

[GTHK]

Are you looking at source or destination port? Disable UPnP.

[bats059]

Hi GTHK, thanks for responding.

the utorrent setup calls it the listening port, so I assumed it was incoming (destination) port and have set my firewall (a mikrotik) accordingly.

Looking at the incoming packets however, there are currently 31 seeds, every one is using a different source and destination port- and none of them is the current "listening" port I set up in utorrent.

I have tried it with uPnP enabled and disabled, it didn't seem to make any difference. I'd guess the utorrent upnp is not compatible with the upnp on my firewall?

[paintball9]

The port listed beside those seeds is their listening port. They don't have to line-up. uTorrent will send out and recieve from your port and connect to theirs on that number. If you've done port-forwarding then uPnP is not required and in some cases may cause problems trying to reserve the ports a second time. Turn off NAT if you haven't as well.

When forwarding make sure you forward both TCP and UDP for the port you have selected.

As for the incoming not matching the firewall. Are you sure you've forwarded the same port that is listed in the utorrent settings. Also if you have two network devices (eg a modem and a router) you may have to forward from the first device to the second and then to your system. (the alternative is putting once device in bridge-mode

[GTHK]

No upnp when forwarding manual. Are you looking at a firewall for the port info or uT peers tab? Try a different port and port test.

[Switeck]

Probably both UPnP and NAT-PMP needs to be disabled.

[bats059]

Problem solved guys- the comment about turning off nat set me thinking- a bit of stuffing around and I now have a couple of destination nat rules that have fixed it. (I can't just turn nat off- my connection to my ISP requires it, it won't work without nat)

Thanks for the help- much appreciated.