my intranet application is not working. it throws letner fail. how can i restart the listern. in command promt i have tried listctl start.. and reload and all.. but its not yet worked. i am not able to connect the db in sql plus also. it also shows no listner. how can i resolve this issue.. please help..

You should be more specific: OS, Oracle version, ORA codes.

If you get ORA-12541:
- first check the tnsnames.ora file and ensure that it points to the correct server and port
- on your server, ensure that your listener service is running, using lsnrctl status
- try to start the listener service using lsnrctl start