IP detection behind proxy server

[wbauchus]

I've got a site where I utilize IP detection to prevent fraud. But my problem is proxy servers, like AOL and the anonymous services. Does anyone know of a script or effective method for detecting an IP address behind a proxy server?

[edited by: tedster at 6:09 pm (utc) on Jan. 8, 2006]
[edit reason] moved from another forum [/edit]

[tedster]

If I ever hear of such a thing I would jump on it -- but I think it's very unlikely. The whole point of using proxy servers is that they hide the originator. This is one of those things I just live with.

[DamonHD]

Hi,

I actively BLOCK access to my main site via anonymous proxies as there is no good reason to use one with my site, and I want to make it harder for dubious users (eg scrapers) to cover their tracks.

I get a 5%--10% drop in bandwidth as a consequence.

I use the open-proxy lists at SORBS to do the lookup in real time.

Rgds

Damon

PS. Note that I also block access from SPAMmer/compromised machines using the SPAMHAUS xbl-sbl list. YMMV...

[wbauchus]

It's looking like something I'll just have to deal with. I don't want to ban some innocent person who has no idea that AOL or a legitimate service provider is hiding their real IP because of one or two people who hide intentionally. And unfortunately most of the methods that pop up on Google don't seem to return any usable results.

[Romeo]

There are 2 types of proxies (or proxy configurations):
(1) those who send information about their clients, and (2) those who don't.

You can look into the HTTP_X_FORWARDED_FOR and CLIENT_IP environment variables to get at least some additional information in case (1) - its use depends on the proxy.
You are lost in case (2), though.

Regards,
R.