Before the oracle10g,you must execute “set password” after you execute the command “change_password”.for example:

LSNRCTL> stat

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC)))

STATUS of the LISTENER

------------------------

Alias                     LISTENER

Version                   TNSLSNR for Linux: Version 9.2.0.4.0 - Production

Start Date                12-7月 -2010 08:50:19

Uptime                    69 days 7 hr. 6 min. 44 sec

Trace Level               off

Security                  ON

SNMP                      OFF

Listener Parameter File   /home/oracle/oracle92/network/admin/listener.ora

Listener Log File         /home/oracle/oracle92/network/log/listener.log

Listening Endpoints Summary...

  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC)))

  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=localhost.localdomain)(PORT=1521)))

Services Summary...

Service "PLSExtProc" has 1 instance(s).

  Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...

Service "zxin" has 2 instance(s).

  Instance "zxin", status UNKNOWN, has 1 handler(s) for this service...

  Instance "zxin", status READY, has 1 handler(s) for this service...

The command completed successfully

LSNRCTL> change_password

Old password:

New password: fztxttqh

Reenter new password: fztxttqh

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC)))

Password changed for LISTENER

The command completed successfully

LSNRCTL> save_config

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC)))

TNS-01169: The listener has not recognized the password

LSNRCTL> stat

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC)))

TNS-01169: The listener has not recognized the password

LSNRCTL> set password    -----you must set password to get the passprot

Password: fztxttqh

The command completed successfully

LSNRCTL> save_config

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC)))

Saved LISTENER configuration parameters.

Listener Parameter File   /home/oracle/oracle92/network/admin/listener.ora

Old Parameter File   /home/oracle/oracle92/network/admin/listener.bak

The command completed successfully

LSNRCTL> stat

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC)))

STATUS of the LISTENER

------------------------

Alias                     LISTENER

Version                   TNSLSNR for Linux: Version 9.2.0.4.0 - Production

Start Date                12-7月 -2010 08:50:19

Uptime                    69 days 7 hr. 10 min. 53 sec

Trace Level               off

Security                  ON

SNMP                      OFF

Listener Parameter File   /home/oracle/oracle92/network/admin/listener.ora

Listener Log File         /home/oracle/oracle92/network/log/listener.log

Listening Endpoints Summary...

  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC)))

  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=localhost.localdomain)(PORT=1521)))

Services Summary...

Service "PLSExtProc" has 1 instance(s).

  Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...

Service "zxin" has 2 instance(s).

  Instance "zxin", status UNKNOWN, has 1 handler(s) for this service...

  Instance "zxin", status READY, has 1 handler(s) for this service...

The command completed successfully

In oracle10g and above,because of the parameter “LOCAL_OS_AUTHENTICATION_ ” is set ON by default,you should not to be set password after you change_password.

To disable this feature,you can do this:

1. Stop the listener.

2. Add the parameter in the listener.ora file and save it:

LOCAL_OS_AUTHENTICATION_ = OFF

3. Restart the listener and check status output:

If you forget the password,how can you change the config of the listener?

kill the tnslsnr process using kill -9.  Then remove the line PASSWORDS_ from the listener.ora file