How to get a user's client IP address in ASP.NET?

Question

We have Request.UserHostAddress to get the IP address in ASP.NET, but this is usually the user\'s ISP\'s IP address, not exactly the user\'s machine IP address

Answer 1

Combining the answers from @Tony and @mangokun, I have created the following extension method:

public static class RequestExtensions
{
    public static string GetIPAddress(this HttpRequest Request)
    {
        if (Request.Headers["CF-CONNECTING-IP"] != null) return Request.Headers["CF-CONNECTING-IP"].ToString();

        if (Request.ServerVariables["HTTP_X_FORWARDED_FOR"] != null)
        {
            string ipAddress = Request.ServerVariables["HTTP_X_FORWARDED_FOR"];

            if (!string.IsNullOrEmpty(ipAddress))
            {
                string[] addresses = ipAddress.Split(',');
                if (addresses.Length != 0)
                {
                    return addresses[0];
                }
            }
        }

        return Request.UserHostAddress;
    }
}