Proxy

What is a proxy?

Basically a middleman. When you are browsing a site through a proxy your requests are sent to the proxy and the proxyforwards them to the site instead of you connecting directly to the site. There are several classifications(the terminology is far from standard):

 “;Transparent “;A transparent proxy is one that needs no configuration on the clients. It works by automatically redirecting all port 80 traffic to the proxy. (Sometimes used as synonymous for non-anonymous.)
 “;Explicit/Voluntary “;Clients must configure their browsers to use them.
 “;Anonymous “;The proxy sends no client identification to the server. (HTTP_X_FORWARDED_FOR header is not sent;”; the server does not see your IP.)
 “;Highly Anonymous “;The proxy sends no client nor proxy identification to the server. (HTTP_X_FORWARDED_FOR, HTTP_VIA and HTTP_PROXY_CONNECTION headers are not sent;”; the server doesn’t see your IP and doesn’t even know you’re using a proxy.)
 “;Public “;(Self explanatory)

A transparent proxy may or may not be anonymous, and there are several levels of anonymity.

How do I find out if I’m behind a (transparent/anonymous) proxy?

Try ProxyJudge. It lists the HTTP headers that the server where it is runningreceived from you. The relevant ones are HTTP_CLIENT_IP, HTTP_X_FORWARDED_FOR and REMOTE_ADDR.

Why is my port listed as “”;—“”; even though I’m not NAT/Firewalled?

The tracker is quite smart at finding your real IP, but it does need the proxy to send the HTTP headerHTTP_X_FORWARDED_FOR. If your ISP’s proxy does not then what happens is that the tracker will interpret the proxy’s IPaddress as the client’s IP address. So when you login and the tracker tries to connect to your client to see if you areNAT/firewalled it will actually try to connect to the proxy on the port your client reports to be using forincoming connections. Naturally the proxy will not be listening on that port, the connection will fail and thetracker will think you are NAT/firewalled.

Can I bypass my ISP’s proxy?

If your ISP only allows HTTP traffic through port 80 or blocks the usual proxy ports then you would need to use somethinglike socks and that is outside the scope of this FAQ.

Otherwise you may try the following:

  • Choose any public non-anonymous proxy that does not use port 80 (e.g. from this, this or this list).
  • Configure your computer to use that proxy. For Windows XP, do StartControl PanelInternet OptionsConnectionsLAN SettingsUse a Proxy serverAdvanced and type in the IP and port of your chosen proxy. Or from Internet Explorer use ToolsInternet Options, …
  • (Facultative) Visit ProxyJudge. If you see an HTTP_X_FORWARDED_FOR in the list followed by your IP then everything should be ok, otherwise choose another proxy and try again.
  • Visit this site. Hopefully the tracker will now pickup your real IP (check your profile to make sure).

Notice that now you will be doing all your browsing through a public proxy, which are typically quite slow.Communications between peers do not use port 80 so their speed will not be affected by this, and should be better than whenyou were “”;unconnectable””;.

How do I make my bittorrent client use a proxy?

Just configure Windows XP as above. When you configure a proxy for Internet Explorer you’re actually configuring a proxy forall HTTP traffic (thank Microsoft and their “”;IE as part of the OS policy””; ). On the other hand if you use anotherbrowser (Opera/Mozilla/Firefox) and configure a proxy there you’ll be configuring a proxy just for that browser. We don’tknow of any BT client that allows a proxy to be specified explicitly.

Why can’t I signup from behind a proxy?

It is our policy not to allow new accounts to be opened from behind a proxy.