when you use Plsql to connect to a database after startup starts the database ,
ora-12170 error occurred:Make sure to check the status of the Oracle listener using the LSNRCTL status command before starting, shutting down, or restarting the Oracle Listener: 1, $lsnrctl Status: Check the state of the current listener 2, $lsnrctl start [ Listener-name] Start all listeners, you can specify a name to start a specific listener 3, $lsnrctl stop [listener-name] to turn off all listeners, you can specify a name to close a particular listener 4, $lsnrctl reload Restart the listener, this command can replace Lsnrctl stop,lsnrctl start5, Lsnrctl hep can display all the available Listener commands Common command parameters: Start-start the Oracle Listener
Stop-stop the Oracle Listener
Status-display the current status of the Oracle listener
Services-retrieve The Listener Services information
Version-display The Oracle Listener version information
Reload-this would reload the Oracle Listener SID and parameter files. This is equivalent to Lsnrctl stop and lsnrctl start.
Save_config-this would save the current settings to the Listener.ora file and also take a backup of the Listener.ora file Before overwriting it. If There is no changes, it would display the message "No changes to save for LISTENER"
Trace-enable the tracing at the listener level. The available options is ' Trace OFF ', ' Trace USER ', ' Trace ADMIN ' or ' trace support '
Spawn-spawns a new with the program with the Spawn_alias mentioned in the Listener.ora file
Change_password-set the new password to the Oracle Listener (or) Change the existing listener password.
Show-display log files and other relevant listener information
ora-12170 and Oracle Lsnrctl
