ORA-12162: TNS:net service name is incorrectly specified

Cause: The connect descriptor corresponding to the net service name in  TNSNAMES.ORA or  in the directory server (Oracle Internet Directory) is incorrectly specified. Action: If using local naming make sure there are no syntax errors in the  corresponding connect descriptor in the TNSNAMES.ORA file. If using directory naming check the  information  provided through the administration used for directory naming. Example: oracle@hostname:~$ sqlplus scott SQL*Plus: Release 11.2.0.1.0 Production on Wed Feb 26 15:34:14 2014 Copyright (c) 1982, 2009, Oracle.  All rights reserved. Enter password: ERROR: ORA-12162: TNS:net service name is incorrectly specified Solution: Windows: set ORACLE_SID=PROD Linux: Set oracle home if not set, you can check it by “echo $ORACLE_HOME” oracle@hostname:~$ export ORACLE_HOME=/opt/oracle/product/ora12r2 oracle@hostname:~$ export ORACLE_SID=PROD oracle@hostname:~$ sqlplus scott SQL*Plus: Release 11.2.0.1.0 Production on Wed Feb 26 15:39:22 2014 Copyright (c) 1982, 2009, Oracle.  All rights reserved. Enter password: Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production With the Partitioning and Automatic Storage Management options SQL>