oracle@kitcomp bin]$ tnsping prod

TNS Ping Utility for Linux: Version 10.1.0.3.0 - Production on 03-DEC-2007 02:16:00

Copyright (c) 1997, 2003, Oracle.  All rights reserved.

Used parameter files:
/u01/app/oracle/OraHome_1/network/admin/sqlnet.ora


Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = kitcomp.tapasi.com)(PORT = 1521))) (CONNECT_DATA = (SERVICE_NAME = PROD)))
OK (0 msec)
[oracle@kitcomp bin]$ sqlplus "scott/tiger@prod"

SQL*Plus: Release 10.1.0.3.0 - Production on Mon Dec 3 02:16:18 2007

Copyright (c) 1982, 2004, Oracle.  All rights reserved.

ERROR:
ORA-12514: TNS:listener does not currently know of service requested in connect
descriptor

12:54:44 SQL> column owner            format a12
12:54:44 SQL> column db_link          format a32
12:54:44 SQL> column user_name        format a12
12:54:44 SQL> column host             format a12
12:54:44 SQL> set lines 131
12:54:44 SQL> select * from dba_db_links
12:54:44   2  /

SQL> select * from dba_db_links;

no rows selected

[oracle@kitcomp bin]$ ./lsnrctl stat

LSNRCTL for Linux: Version 10.1.0.3.0 - Production on 03-DEC-2007 23:24:41

Copyright (c) 1991, 2004, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=kitcomp.tapasi.com)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 10.1.0.3.0 - Production
Start Date                03-DEC-2007 23:16:12
Uptime                    0 days 0 hr. 8 min. 29 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /u01/app/oracle/OraHome_1/network/admin/listener.ora
Listener Log File         /u01/app/oracle/OraHome_1/network/log/listener.log
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=kitcomp.tapasi.com)(PORT=1521)))
Services Summary...
Service "PROD.KITCOMP.TAPASI.COM" has 2 instance(s).
  Instance "PROD", status UNKNOWN, has 1 handler(s) for this service...
  Instance "prod", status READY, has 1 handler(s) for this service...
Service "prodXDB.kitcomp.tapasi.com" has 1 instance(s).
  Instance "prod", status READY, has 1 handler(s) for this service...
The command completed successfully

PROD =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = kitcomp.tapasi.com)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = PROD)
    )
  )