Oracle listener not running and won't start

Question

I am getting the following errors while from the lsnrctl status command:

C:\\Users\\pna105>lsnrctl stat

 LSNRCTL for 64-bit Windows: Version 11.         


        

Answer 1

1.Check the Environment variables (must be set for System and not for user):

ORACLE_HOME = C:\oraclexe\app\oracle\product\11.2.0\server
ORACLE_SID = XE

2.Check if you have the right definition in listener.ora

XE =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1))
      (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
    )
  )

DEFAULT_SERVICE_LISTENER = (XE)

3.Restart the service (Services > OracleServiceXE)

After that you may see a new service called OracleXETNSListenerXE.
There is already an old OracleXETNSListener.

I started both and then I was able to make a successful connection.

Edit:

If everything is running but you still can't connect, check if there is no error: ORA-12557: TNS:protocol adapter not loadable.

To correct the error go back to the Environment variables and this time edit the one called: Path. Be sure that C:\oraclexe\app\oracle\product\11.2.0\server\bin is somewhere at the beginning, definitely before any other path pointing to a different version of the Oracle DB.