Im pretty sure there is a way but does anyone know how to stop proxy servers accessing your site in php.

Thanks

I remember something about an "X-Forwarded-for" entry added to the http header when one uses a proxy to make http request.

But I can't remember much more about it. You'll just have to keep searching from there

I think there is no way to block all proxies. Some proxies don't use the http header X-Forwarded-For. The only way I can think of to filter all proxies is to make a list of all the proxy servers out there, but considering the fact that there are probably thousants if not millions of proxyservers, and new ones appear each day, this might cause some delay

banning all proxies is two things

1) impossible
2) pointless


First of all proxies have good sides too, for one they speed up the internet. A proxy is nothing more than a pc between you and the website. if somebody asks me in IRC if i could download a page for him I would be a proxy ... try and stop that ..
(Imagine a protocol less labour intensive than irc and you'll get the idea.

However you will block out everybody using a Proxy if ( IQ<80 || nooblevel==1)

there are some tricks like the X-FORWARDED-FOR and you could "portscan" your visitors for open common proxy gates as there are
8080 8000 3271 80 ...

i know blocking out all and every proxy available is impossible but i wanted to stop a few becuase i run a game site and if someone gets into someone else's account and uses a proxy on it then it is undetectable. I thought about making it so they could only login with their ip address but if they go to their friends house or they have a dynamic ip then it would cause problems.