How to find IP address just with session IDs?

Question

Actually it's a simple question but I couldn't asked the correct question to google maybe. Here is the problem:

Think that I have a website to which clients connect. I store session IDs (ie sbf1qql1qikvr4vnsvbomr1d61) for each connected client and I want to retrieve IP adresses using these session IDs. I'm running a php code

root@34s:~# php checkSessions.php

on the server machine. And checkSessions.php has a code similiar to the following snipplet

//Enter an infinite loop
while(1)
{
            //Get session ids and user ids from the database 
    $q1 = $db->getQ("SELECT user_id, session_id, FROM all_sessions");
    foreach($q1 as $q)
    {
        if($q[0]==63)
        {
                         // Now, I need to get IP adress. I only have a session id
        }
    }

           // Wait 2 seconds and do the same procedure again 
       sleep(2);
}

So, could you provide any method to find out the IP adress of the client using this session ID.

Answer 1

Sessions do not store IP addresses or any other extra information. You need to add it to the session when it is started. ie:

session_start();
$_SESSION['ip'] = $_SERVER['REMOTE_ADDR'];