Home
Trouble shooting
 

Cry about...
Oracle Troubleshooting


ORA-12224: TNS: no listener


Symptom:

When trying to connect to Oracle the following error is generated:

ORA-12224: TNS: no listener

Cause:

The connection request could not be completed because the listener is not running. This can be confirmed using the command:

lsnrctl status

on the database server.

Remedy:

  • Start the listener on the remote machine. (Use ‘lsnrctl start’).

  • If the server name has recently been changed then try running ‘Net 8 Configuration Assistant’ and select ‘Listener Configuration’. Work through the dialogs without changing anything and it will automatically update the server name. The listener can then be started. (Oracle 8 - but may apply to earlier versions.)

  • Ensure that the supplied destination address matches one of the addresses used by the listener - compare the TNSNAMES.ORA entry with the appropriate LISTENER.ORA file.