When em trying to connect db client with the problem TNS the db throws below error
Listener refused the connection with following error: ORA-12505, TNS: listener does not currently know of SID given in connect descriptor.
Checked the TNS everything looks fine.
Login to db server :
Checked ORACLE_SID & ORACLE_HOME environment variables are properly set or not. They looks fine.
Next in command line or putty
$lsnrctl status (to the know the status of current listener)
the log indicated me listener started with no services. Googled the to understand the issue found out I need to run below command inorder to link db with listener.
Logged as : sqlplus / as sysdba & excuted below command by changing the host & port
alter system set local_listener=' (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=test.local)(PORT=1521)))'
Then excuted the $lsnrctl status
the log indicated listener connected with db instance, and TNS entries may be the issue need to verify TNS entry at db client.
after that successfully connected to oracle db client