Cambiando El Puerto de Listener

Las bases de datos Oracle trabajan por defecto por el Puerto 1521 , si quieres que no sea tan obvio para alguien hallar tu base de datos, puedes probar cambiando el puerto del listener, he aquí un ejemplo.

En la ruta
/oracle/app/oracle/10.2.0/db/network/admin

Hallamos el archivo de configuración del listener, llamado listener.ora
allí cambiamos el numero del puerto al que queremos.

LISTENER_TEST =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = TEST1)(PORT = 4543))
    )
 )


Luego en nuestra base de datos debemos cambiar el parametro local_listener
sqlplus / as sysdba
SQL>  show parameter local_listener
NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
local_listener                       string

SQL>alter system set local_listener='(ADDRESS=(PROTOCOL=TCP)(HOST=TEST1)(PORT=4543))' sid='TEST' ;

SQL> show parameter local_listener
NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
local_listener                       string      (ADDRESS=(PROTOCOL=TCP)(HOST=TEST1)(PORT=4543))

Luego debemos reinicar el listener, para que los cambios tengan efectos

lsnrctl stop LISTENER_TEST
lsnrctl start LISTENER_TEST

TNSLSNR for Linux: Version 10.2.0.3.0 - Production
System parameter file is /oracle/app/oracle/10.2.0/db/network/admin/listener.ora
Log messages written to /oracle/app/oracle/10.2.0/db/network/log/listener_test.log
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=TEST1)(PORT=4543)))
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=TEST1)(PORT=4543)))

STATUS of the LISTENER
------------------------
Alias                       LISTENER_TEST
Version                   TNSLSNR for Linux: Version 10.2.0.3.0 - Production
Start Date               01-FEB-2011

Uptime                   0 days 0 hr. 0 min. 0 sec
Trace Level             off
Security                  ON: Local OS Authentication
SNMP                     OFF
Listener Parameter File   /oracle/app/oracle/10.2.0/db/network/admin/listener.ora
Listener Log File         /oracle/app/oracle/10.2.0/db/network/log/listener_test.log
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=TEST1)(PORT=4543)))
The listener supports no services
The command completed successfully

lsnrctl status LISTENER_TEST

LSNRCTL for Linux: Version 10.2.0.3.0 - Production on 01-FEB-2011
Copyright (c) 1991, 2006, Oracle.  All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=TEST1)(PORT=4543)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER_TEST
Version                   TNSLSNR for Linux: Version 10.2.0.3.0 - Production
Start Date                01-FEB-2011 09:12:52
Uptime                    0 days 0 hr. 2 min. 14 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /oracle/app/oracle/10.2.0/db/network/admin/listener.ora
Listener Log File         /oracle/app/oracle/10.2.0/db/network/log/listener_test.log
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=TEST1)(PORT=4543)))
Services Summary...
Service "TEST" has 1 instance(s).
  Instance "TEST", status READY, has 1 handler(s) for this service...
Service "TESTXDB" has 1 instance(s).
  Instance "TEST", status READY, has 1 handler(s) for this service...
Service "TEST_XPT" has 1 instance(s).
  Instance "TEST", status READY, has 1 handler(s) for this service...
The command completed successfully