sql2000連接失敗

我在本地測試jsp.出現下面錯誤，怎麼回事啊？，高手大大們
++++++++++++++++++++++++++++++++++++++
java.sql.SQLException: [Microsoft][SQLServer 2000 Driver for JDBC]Error establishing socket.
at com.microsoft.jdbc.base.BaseExceptions.createException(Unknown Source)
at com.microsoft.jdbc.base.BaseExceptions.getException(Unknown Source)
at com.microsoft.jdbc.base.BaseExceptions.getException(Unknown ++++++
驅動都已經放好，
連接語句:
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver").newInstance();
   Connection con=java.sql.DriverManager.getConnection("jdbc:microsoft:sqlserver://172.16.21.22:1433;DatabaseName=jspdev","jspdev","jspdev");