listening on two ports

[spx]

hi, can somebody tell me why utorrent is listening two ports instead of one?

a strange 10000 port appeared after upgrading to 2.0 beta. its not a web ui - web ui is disabled.

here is a screenshot:

http://pic.ipicture.ru/uploads/091118/lUsSo8BgEC.jpg

thx for your help

[Ultima]

Port 10000 is used as a "well-defined" port used for external applications to detect µTorrent and pair with it.

[spx]

this is new feature in µT? i've never seen it in previous versions..

ok, then what firewall rule should i apply to deal with that port?

something like "allow from localhost to localhost, from port any to port 10000, where protocol is tcp" ?

or by "external applications" you mean any internet applications, not local?

[Ultima]

At the very least, WebUI pairing as enabled by allow_pairing is only for use with local applications. Remote applications cannot pair with WebUI.

The port itself is apparently meant for more than just WebUI pairing, and in that regard, I'm not completely certain whether Internet applications are meant to be allowed to use that port.

[Switeck]

Should I stop mentioning ports 10000-65000 for uTorrent's listening port then?

...Because someone might choose port 10000 and wonder why uTorrent is still firewalled.

[spx]

i have disabled "allow_pairing" function, but uTorrent is still listening on 10000. is that ok?

also, if there are 2 copies of uTorrent running on my pc, how the pairing function will react?

i see that second instance is listening on 10015. Pairing will not work on it?

[Ultima]

The port itself is apparently meant for more than just WebUI pairing, and in that regard, I'm not completely certain whether Internet applications are meant to be allowed to use that port.

As such, disabling pairing intentionally doesn't disable listening on that port. What happens if there are multiple instances running? I'm not sure. As far as I know, there is a set of well-known ports to be used for this purpose -- it won't just be port 10000.

[spx]

so, no way to remove listening on second port?

ok, thanks for help

[Ultima]

Not currently as far as I know. I would definitely want a way to do so myself, as I don't think I'll *ever* need or want the services provided by these ports.

[rocketmonkeys]

I also noticed this, and messes up some other programs I have running on my computer. Is there really no way to turn off this port? It seems like there should be an option, or at the very least something in the "advanced" section.

[Firon]

This should be possible to disable, but it's not yet. It will be in the near future (as an advanced option, probably something like discoverable_port).

The client will change its port if 10000 is taken using some predictable formula, so pairing apps can still find it.

The port will only allow pairing from localhost and requires authentication. You can do regular WebUI requests to it, but only if the standard WebUI is actually enabled (and it still needs authentication). Otherwise, it's limited to just paired applications. Paired apps themselves require the user to accept before it will work. The client pops up a message asking if you wanna pair, basically.

It's basically a zero-conf way of having x application on your system talk to ut's webui, e.g. a vista sidebar or whatever.

What do you have listening on port 10000 anyway?

[rocketmonkeys]

I have tons of applications on my computer, both listening on localhost and the public/all interfaces. I have a local development copy of one of my web applications running sometimes on port 10000 on the '*' interface. It only runs when I'm working on that project. I have many applications running at some times and not others, on many different ports. It's pretty crowded.

Having utorrent take over a port, even if it's just bound to localhost, and not have any way to turn it off is problematic. It's not just a matter of checking if it's being used when utorrent starts up; that's easy. As in this example, when utorrent takes over a port it messes up any other applications that start after it. And since utorrent is bound to localhost and the other program is bound to *, they don't conflict - it just fails silently since I go to http://localhost:10000/ in my browser, but I get utorrent instead of the other program.

I can understand the desire to provide a zero config way for programs to access each other. However, it seems like any port utorrent uses should at the very least have a way to enable/disable it, and further should be able to change the port.

I'll switch back down to the non-beta version until this is fixed. Thanks for the explanation, it's interesting to see what's going on inside.

[Ash88]

Webmin uses port 10000 by default. It (unfortunately) demands that port 10000 be available when installing and fails the install with an exit code if it isn't. Even if you don't have utserver running during install, unless you know about this conflict the next time you start utserver after installing webmin you are going to have problems.

After installing webmin you can change the default port, solving the issue. But this is pain to remember if you are managing multiple servers and have come to rely on port 10000 as the webmin port.

Should this feature be disabled by default on the server?

**EDIT: Actually, if you disable utserver, install webmin, and then restart utserver afterwards then it solves the problem. You don't have to change the webmin port.

Cheers - and thanks for utserver - it's awesome!