TNS: Connection Closed.

Few days back day got an error on my DB all of sudden , TNS Connection closed . After looking up MOS learned that . One of the several reason could be that your library files are not linked correctly and will have to relink them. 

Sharing the output of the incident with the soln.


[ORCL]$ sqlplus kumarn/*****
SQL*Plus: Release 10.2.0.5.0 - Production on Tue Feb 26 17:38:40 2013
Copyright (c) 1982, 2010, Oracle.  All Rights Reserved.
ERROR:
ORA-12547: TNS:lost contact
Enter user-name:

[ORCL]$ sqlplus kumarn/****@ORCL
SQL*Plus: Release 10.2.0.5.0 - Production on Tue Feb 26 17:38:56 2013
Copyright (c) 1982, 2010, Oracle.  All Rights Reserved.
ERROR:
ORA-12537: TNS:connection closed

[ORCL]$ oerr ora 12537
12537, 00000, "TNS:connection closed"
// *Cause: "End of file" condition has been reached; partner has disconnected.
// *Action: None needed; this is an information message.

Sol: Relinked the Oracle Home again as the owner of  the Oracle 

$ORACLE_HOME/bin/relink all

[ORCL]$ sqlplus kumarn/*****SQL*Plus: Release 10.2.0.5.0 - Production on Tue Feb 26 17:45:00 2013
Copyright (c) 1982, 2010, Oracle.  All Rights Reserved.
SQL> select * from global_name;

GLOBAL_NAME
-------------
ORCL