explain how / when Listening port vs Proxy SOCKS port are used

[amber89]

Hi,

Can someone explain (to newbie) the actual differences in preferences>connection, how / when / for what type files or site connections the "Listening Port" # is used vs Proxy (type - socks, http, etc) Port #?

1) Are they both used simultaneously if using a proxy? Or does it depend on site and / or torrent, etc?

2) If you enter a Proxy server type & port #, is the Listening Port # ignored? Noticed when entered a Proxy port #, uTorrent auto changed Listening Port to same # (not sure of impact).

3) If using Proxy, should there even BE a Listening Port # entered, & should it be SAME as proxy port?

4) For uTorrent Proxy Server Type, how do I determine which type (HTTP or SOCKS[5?]) to select? Or is it trial / error?

Notice in Firefox, also has separate proxy settings for HTTP & SOCKS port #s.

Thanks!

[Switeck]

It is possible (but often unwanted) to have traffic coming from the listening port AND proxy port.

[xoskbcnh]

If my goal is to route all my traffic through my proxy for anonymity, how do I ensure this? My tests so far show that utorrent appears to ignore the proxy I set up and instead uses the "Listening Port".

If there is a problem on my remote proxy, it's not telling me this. (Using the same tunnel as an http proxy works just fine).

Thanks in advance for any insight

[Switeck]

I don't use a proxy or VPN, so take what I say with a grain of salt...

But..try unforwarding uTorrent's listening port on your router.

Disable DHT, Resolve IPs, and probably even Teredo/IPv6 and uTP.

Most proxies can barely proxy HTTP tracker updates, let alone TCP peer/seed connections.

...And they can't do the UDP stuff.

Only a VPN would handle all of uTorrent's traffic.

Having a software firewall block anything on uTorrent's listening port *IF* it comes from something other than the proxy's ip might work...

Still, that leaves outgoing traffic problems.

...And I'm not sure how to firewall that so it only goes through the proxy.

[xoskbcnh]

Well, there are options in the configuration to use a proxy.

The question is how is the proxy features *supposed* to function? What traffic is supposed to go through this proxy?

[Firon]

Outgoing TCP connections (tracker communication, outgoing TCP connections you initiate). That's it.

[xoskbcnh]

I am unfamiliar with the specifics of the bittorrent protocol, but that sounds like "just a little bit" of the traffic and not the "bulk" of it, right?

If I wanted to pursue routing all my traffic through an ssh tunnel, do you have a recommended setup? Would I want two tunnels (one for the items going through the "proxy" that you mention) and one for the "bulk" of the traffic - that equals the second ssh tunnel?

Thanks in advance for your advice.

---------------------

I got a helpful response on IRC that I thought might help others. Also here for my consideration as I continue to tinker with this.

(3:45:34 PM) Firon: xoskbcnh: you need to explicitly tell it to proxy peer communication, but this only proxies TCP traffic

(3:45:50 PM) Firon: so you'll have to disable anything that generates UDP traffic (except DNS), or block it in your firewall

(3:46:09 PM) Firon: this would be DHT and uTP, which you can turn off by disabling "enable bandwidth management"

(3:46:21 PM) Firon: we do plan on implementing UDP support in our SOCKS proxy eventually, but for now this is all you can do

(3:47:00 PM) Firon: in addition, you'll need to check the trackers of your torrents and see if they have UDP trackers and remove them if they exist

(3:47:13 PM) Firon: or you could use a VPN, which is probably a lot easier

(3:47:19 PM) Firon: and that will proxy everything

(3:47:57 PM) xoskbcnh: oh ok

(3:48:05 PM) xoskbcnh: interesting, thank you for the info

(3:48:37 PM) xoskbcnh: that's a lot to digest, i'll tinker with it a bit

(3:49:09 PM) Firon: SOCKS proxy support is TCP only at the moment, though the protocol itself supports UDP

[Firon]

You can only use one proxy. µTorrent does not support more than one proxy.

[SpasV]

I'll try to explain the way I understand.

The BitTorrent applications, like uTorrent, work in IP (Internet Protocol) networks. This means they are capable of communicating each other using Internet Protocol Suite (of protocols).

For two applications to comunicate over an IP network they need to be uniquely identified. The pair IP address:port or IP:port (so called socket) serves this purpose. The IP address uniquely identifies a NIC (Network Interface Card) and if there is only one NIC connected to an IP network it identifies the computer also. The port uniquely identifies an application running in the computer connected to an IP network.

What is called listening port is this identifier. It is called "listening" because through it an application receives the incoming information sent to it and it needs to "listen", to be waiting to receive this information.

So, the listening port is a local identifier and it needs to be unique for that computer. It has nothing in common with a proxy.

There are two kinds of communications between applications implementing BitTorrent protocol used in p2p for file sharing:

The first one is between an application running in an user's computer and application (Tracker) running in a server computer. Through these communications the user's applications receive from Tracker a list (IP:port) of participating users, their status (seeder, leecher), exchange statistical information.

This kind of communication is implementing over HTTP (Hiper Text Transfer Protocol).

The second kind of communication is between the user's applications. Its purpose is to exchange the shared files. This kind is implementing over TCP/IP protocol (TCP/IP is a part of the IP suite and it is implemented by the computer OS).

There is a possibility for two applications communicating in an IP network to use a proxy.

There are two kinds of proxy servers: HTTP proxy and SOCKS proxy.

Simply said:

If you need the first kind of BitTorent communications (between an user's application and Tracker) use HTTP proxy.

If you need the second kind of BitTorent communications (between user's applications) use SOCKS proxy.

SOCKS allows to work with any protocols: SOCKS 4 - with TCP, SOCKS 5 - with TCP and UDP.

NOTE: A SOCKS proxy opens a TCP/IP connection between the target application and itself. It transfers the data between you and the target application and my I guess is it puts the original TCP/IP packet in its own packet this way hiding the original packet and preserving your anonymity.

Finally:

A proxy server is an application running in a proxy server computer. So, you need to tell uTorrent its unique IP network identifier (IP:port)

Here are some well known port numbers:

http 80/tcp World Wide Web HTTP

http 80/udp World Wide Web HTTP

http-alt 8080/tcp HTTP Alternate (see port 80)

http-alt 8080/udp HTTP Alternate (see port 80)

socks 1080/tcp Socks

socks 1080/udp Socks

I hope this will help.