Check Connection String: # sqlplus sys/password@'(DESCRIPTION=(ADDRESS = (PROTOCOL = TCP)(HOST = host1.test.com)(PORT = 1521))(CONNECT_DATA=(SERVER = DEDICATED)(SERVICE_NAME=host1)))' as sysdba Enter password: ERROR: ORA-12541: TNS:no listener If you get error like above. Check listener is running and the service is added in the listener. # lsnrctl status (If your listener is stop then start your listener using “lsnrctl start”)
ORA-12514: TNS:listener does not currently know of service requested in connect Descriptor If you get error like above check service in listener. # lsnrctl services (If service is not in the list add the service)
Check connection string after fixing: # sqlplus sys/password@'(DESCRIPTION=(ADDRESS = (PROTOCOL = TCP)(HOST = host1.test.com)(PORT = 1521))(CONNECT_DATA=(SERVER = DEDICATED)(SERVICE_NAME=host1)))' as sysdba SQL*Plus: Release 11.2.0.3.0 Production on Fri Feb 28 16:07:16 2014 Copyright (c) 1982, 2011, Oracle. All rights reserved. Enter password: Connected to: Oracle Database 11g Enterprise Edition Release 11.1.0.6.0 - 64bit Production With the Partitioning option
SQL> select host_name from v$instance; HOST_NAME --------------------------------------------------------------------------------
host1.test.com |