Ip address of the client machine

Question

Please let me know how to get the client IP address,

I have tried all of the below things , but I am getting the same output: 127.0.0.1

string strClientIP;
strClientIP = Request.UserHostAddress.ToString();

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

string ipaddress = string.Empty ;
ipaddress = Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
if (ipaddress == "" || ipaddress == null)
    ipaddress = Request.ServerVariables["REMOTE_ADDR"];

How can I get the correct IP?

Answer 1

You are on the right track with REMOTE_ADDR, but it might not work if you are accessing the site locally, it will show local host.

REMOTE_ADDR is the header that contains the clients ip address you should check that first.

You should also check to for the HTTP_X_FORWARDED header in case you're visitor is going through a proxy. Be aware that HTTP_X_FORWARDED is an array that can contain multiple comma separated values depending on the number of proxies.

Here is a small c# snippet that shows determining the client's ip:

 string clientIp = context.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
 if( !string.IsNullOrEmpty(clientIp) ) {
  string[] forwardedIps = clientIp.Split( new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries );
  clientIp = forwardedIps[forwardedIps.Length - 1];
 } else {
  clientIp = context.Request.ServerVariables["REMOTE_ADDR"];
 }

Answer 2

If you connect via the localhost address, then your client address will also report as localhost (as it will route through the loopback adapter)