TcpClient tcpc = new TcpClient();
try
{
  tcpc.Connect("whois.networksolutions.com", 43);
}
catch(SocketException ex)
{
  Response.Write(ex.ToString());
  Response.End();
}

String strDomain = "forum.antichat.ru\r\n";
Byte[] arrDomain = Encoding.ASCII.GetBytes(strDomain.ToCharArray());
  
Stream s = tcpc.GetStream();
s.Write(arrDomain, 0, strDomain.Length);

StreamReader sr = new StreamReader(tcpc.GetStream(), Encoding.ASCII);
string strLine = null;

while (null != (strLine = sr.ReadLine()))
{
   Response.Write(strLine + "<br>");
}

tcpc.Close();