Need IP address of client server

public static string GetUserIP()
{
    string ipList = HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];

    if (!string.IsNullOrEmpty(ipList))
    {
        return ipList.Split(',')[0];
    }

    if (!string.IsNullOrWhiteSpace(HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"]))
    {
        return HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];
    }

    return HttpContext.Current.Request.UserHostAddress;
}

string strHostName = "";
            strHostName = System.Net.Dns.GetHostName();

            System.Net.IPHostEntry ipEntry = System.Net.Dns.GetHostEntry(strHostName);

            System.Net.IPAddress[] addr = ipEntry.AddressList;

            label1.Text = addr[addr.Length - 1].ToString();