ORA-12541: TNS no listener

So you have bumped on this error. You have started your database, you have started your listeners… successfully, but still the client is adamant that there is are “no listeners”.

All the website will ask you politely, just to “start your listeners”(lsnrctl start). You can ping the host machine but tnsping gives error. tnsnames.ora, listener.ora and sqlnet.ora are as perfect as they can get… but still “ORA-12541: TNS: no listener”. There is one precaution you need to do. The sequence of starting your database should be:
  • Start the database
  • And then start the listeners
Because listeners register with the database you have started. If you have not started the database, or started listeners before starting the database… listeners do not know which database to register with.

Hold on, you do not need to shutdown your database. If you have already started the database and then the listeners, then go to sqlplus and issue the command
 ALTER SYSTEM REGISTER
 
This should make your client listen to your database 🙂