How to obtain the real IP after using CDN (127.0.0.1)

Published: 2010-02-25

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When a member logs in to virtual hosting or logs in to backend management, it generally obtains the user's client address and records it in the database. However, after the same program is deployed on our company's virtual hosting, the obtained client address is not the user's real IP address or is "127.0.0.1". This can be solved by modifying the part of the code that obtains the client IP address in the following ways.

Method for obtaining the real IP after Supesite uses CDN

File include/main.inc.php, this part

if(getenv('HTTP_CLIENT_IP') && strcasecmp(getenv('HTTP_CLIENT_IP'), 'unknown')) {
$_SGLOBAL['onlineip'] = getenv('HTTP_CLIENT_IP');
} elseif(getenv('HTTP_X_FORWARDED_FOR') && strcasecmp(getenv('HTTP_X_FORWARDED_FOR'), 'unknown')) {
$_SGLOBAL['onlineip'] = getenv('HTTP_X_FORWARDED_FOR');
} elseif(getenv('REMOTE_ADDR') && strcasecmp(getenv('REMOTE_ADDR'), 'unknown')) {
$_SGLOBAL['onlineip'] = getenv('REMOTE_ADDR');
} elseif(isset($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], 'unknown')) {
$_SGLOBAL['onlineip'] = $_SERVER['REMOTE_ADDR'];
}

Replace with

Method for obtaining the real IP after Discuz! uses CDN

nclude/common.inc.php
Find the following code:

if(getenv('HTTP_CLIENT_IP') && strcasecmp(getenv('HTTP_CLIENT_IP'), 'unknown')) {
$onlineip = getenv('HTTP_CLIENT_IP');
} elseif(getenv('HTTP_X_FORWARDED_FOR') && strcasecmp(getenv('HTTP_X_FORWARDED_FOR'), 'unknown')) {
$onlineip = getenv('HTTP_X_FORWARDED_FOR');
} elseif(getenv('REMOTE_ADDR') && strcasecmp(getenv('REMOTE_ADDR'), 'unknown')) {
$onlineip = getenv('REMOTE_ADDR');
} elseif(isset($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], 'unknown')) {
$onlineip = $_SERVER['REMOTE_ADDR'];
}

Replace with:

{
$ip = $ips[$i];
break;
}
}
}
return ($ip ? $ip : $_SERVER['REMOTE_ADDR']);
}
$onlineip = get_real_ip();

IP logs recorded in the 帝国cms backend and IPs recorded for user registration

\e\class\connect.php search in the function egetip() and modify the IP-obtaining code to the above part

Solution for the registered user IP and invitation code owner IP being the same in DZ

Method A:

register.php line 200

showmessage('register_invite_iperror');
change to
//showmessage('register_invite_iperror');

Method B:
In the include/common.inc.php file, change

Code:

Replace with:

Code:
$onlineip=getenv('HTTP_X_FORWARD_FOR');

--------------------

Program for how an ASP website with CDN obtains the user's real IP

function   checkip(checkstring)'Use regex to determine whether the IP is valid
dim   re1
set   re1=new   RegExp
re1.pattern="^[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}$"
re1.global=false
re1.Ignorecase=false
checkip=re1.test(checkstring)
set   re1=nothing
end   function

function   get_cli_ip()'Function to get the real IP: first HTTP_CLIENT_IP, then HTTP_X_FORWARDED_FOR, then REMOTE_ADDR
dim client_ip
if checkip(Request.ServerVariables("HTTP_CLIENT_IP"))=true then
         get_cli_ip = checkip(Request.ServerVariables("HTTP_CLIENT_IP"))
else
         MyArray = split(Request.ServerVariables("HTTP_X_FORWARDED_FOR"),",")
         if ubound(MyArray)>=0 then
                   client_ip = trim(MyArray(0))
                   if checkip(client_ip)=true then
                            get_cli_ip = client_ip
                            exit function
                   end if
         end if
         get_cli_ip = Request.ServerVariables("REMOTE_ADDR")
end if
end   function

6 methods for ASP.NET to obtain IP

Server side:

//Method 1
HttpContext.Current.Request.UserHostAddress;

//Method 2
HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];

//Method 3
string strHostName = System.Net.Dns.GetHostName();
string clientIPAddress = System.Net.Dns.GetHostAddresses(strHostName).GetValue(0).ToString();

//Method 4 (ignores proxy)
HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];

Client side:

//Method 5
var ip = '';
alert("Your IP address is "+ip);

//Method 6 (ignores proxy)
function GetLocalIPAddress()
{
    var obj = null;
    var rslt = "";
    try
    {
        obj = new ActiveXObject("rcbdyctl.Setting");
        rslt = obj.GetIPAddress;
        obj = null;
    }
    catch(e)
    {
        //
    }

    return rslt;
   }

MCT Maulik Patel from India provided a server-side solution, which is very good:

if(Context.Request.ServerVariables["HTTP_VIA"]!=null) // using proxy
{
ip=Context.Request.ServerVariables["HTTP_X_FORWARDED_FOR"].ToString(); // Return real client IP.
}
else// not using proxy or can't get the Client IP
{
ip=Context.Request.ServerVariables["REMOTE_ADDR"].ToString(); //While it can't get the Client IP, it will return proxy IP.
}

Remarks:

1. Some proxies will not send us the real IP address

2. Some clients will not send us IP due to the "header_access deny" security setting

.NET can also refer to http://www.cdnunion.com/articleinfo.php?pid=158 for settings

```