problem with $_SERVER['REMOTE_ADDR']

Question

i used $_SERVER[\'REMOTE_ADDR\'] and it returns client ip address (IP address from which the user is viewing the current page) but at now (and same code) it returns host ip

Answer 1

I have to mention that the array key is case-sensitive, and should be upper-case:

var_dump($_SERVER['remote_addr']);
echo "\n";
var_dump($_SERVER['REMOTE_ADDR']);

Output:

Notice: Undefined index: remote_addr in /home/adam/public_html/2011/01/04/foo.php on line 3
NULL

string(15) "10.0.1.51"

I would var_dump($_SERVER) just to evaluate the state of your world, and go from there.

Answer 2

You should query for HTTP_X_FORWARDED_FOR first and if it isn't assigned use REMOTE_ADDR.

Answer 3

@James @imez

By default the client IP is in $_SERVER['REMOTE_ADDR']. When the user enters your site using a PROXY server (HTTP gateway) it tells you who it's proxing for (HTTP_X_FORWARDED_FOR) and will give it's own Proxy IP in $_SERVER['REMOTE_ADDR'].

Anonymous proxies will omit HTTP_X_FORWARDED_FOR or simply lie to you.

Knowing you have a real client IP isn't possible.