php - How To Track the Real IP Address Behind the Proxy

Question

How can we track the Real IP address behind the proxy using PHP?I mean a pure PHP implementation.Because they can turn off the js of their browsers.BTW when the JS is turn on I may use HTML 5 geolocation so I don't need the IP address to locate the user.

Answer 1

You can look at the X-Forwarded-For HTTP header if one is sent, but there is no guaranteed way to know.