Getting IP Address of client machine.

private string GetIP()
{
    string IpAddress = string.empty;
    1st method:- 
    string HostName = string.empty;
    HostName = System.Net.Dns.GetHostName();
    IpAddress = System.Net.Dns.GetHostAddresses(strHostName).GetValue(1).ToString();
  
    2nd method:- 
    string IpAddress = Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
    if (IpAddress == null)
    {
        IpAddress = Request.ServerVariables["REMOTE_ADDR"];
    }
    return IpAddress;
}