Question

Hello i am using this function to get IP Address of different systems..but everytime it returns the same value: 117.239.82.182

function getRealIpAddr()
{
   if (!empty($_SERVER['HTTP_CLIENT_IP']))   //check ip from share internet
   {
     $ip=$_SERVER['HTTP_CLIENT_IP'];
   }
   elseif (!empty($_SERVER['HTTP_X_FORWARDED_FOR']))   //to check ip is pass from proxy
   {
     $ip=$_SERVER['HTTP_X_FORWARDED_FOR'];
   }
   else
   {
      $ip=$_SERVER['REMOTE_ADDR'];
   }
   return $ip;
}

Answer 1

EDIT: (The answer changed radically after some clarifications in the comments)

You could edit the User-Agent setting of the user’s browsers. To see how to change the setting in various browsers follow this link. Then you should modify your PHP script to read User-Agent of the browser.
In PHP,$_SERVER['HTTP_USER_AGENT'] returns the browser’s User-Agent setting. Eg. you can define as User-Agent something like Company/System/1.02 Bla bla bla. Then when you receive that same string you can assume it is coming from a known host.

Attention that the User-Agent can be easily spoofed. So this method is not secure. The secure solution would be to implement a VPN solution.