ORA-12514 Listener Error on server

Question

How come I keep getting a error message that the TNS Listener does not currently know of service error (ORA-12514) only on my server when trying to connect from the same server as the 10G 10.2.0.3. database is running on? If I do not use the @ connection it works fine as the ORACLE_SID environment variable is set to the instance name in the tnsnames.ora file. My 8i and 9i clients have no problem connecting to this server and the 10g database using the @ in the connection string but I believe their .net services files (tnsnames.ora and sqlnet.ora) are configured native to the versions configured on the clients (8i or 9i).
This is the error from the server and a sucessful connection not using the @ sign in the connection string:
SQL> connect sys@prod as sysdba
Enter password:
ERROR:
ORA-12514: TNS:listener does not currently know of service requested in
descriptor
Warning: You are no longer connected to ORACLE.
SQL> connect [email protected] as sysdba
Enter password:
ERROR:
ORA-12154: TNS:could not resolve the connect identifier specified
SQL> connect sys as sysdba
Enter password:
Connected.
SQL>
Is there something wrong with the listener.ora file on my server? Here is the current listener.ora file current on the host server (10g 10.2.0.3), it's tnsnames.ora file and below this a 9i client tnsnames.ora file which is sucessfully using a tnsnames.ora connection using username@server_name/password.
Any help would be greatly appreciated:
10g 10.2.0.3 Server's .net services files:
tnsnames.ora
# tnsnames.ora Network Configuration File: E:\oracle\ora10g\network\admin\tnsnames.ora
# Generated by Oracle configuration tools.
PROD =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = victory)(PORT = 1521))
(CONNECT_DATA =
(SERVICE_NAME = PROD)
EXTPROC_CONNECTION_DATA =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1))
(CONNECT_DATA =
(SID = PLSExtProc)
(PRESENTATION = RO)
listener.ora
# listener.ora Network Configuration File: E:\oracle\ora10g\network\admin\listener.ora
# Generated by Oracle configuration tools.
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = E:\oracle\ora10g)
(PROGRAM = extproc)
(SID_DESC =
(SID_NAME = PROD.ORACLE)
(ORACLE_HOME = E:\oracle\ora10g)
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1))
(ADDRESS = (PROTOCOL = TCP)(HOST = victory)(PORT = 1521))
sqlnet.ora
# This file is actually generated by netca. But if customers choose to
# install "Software Only", this file wont exist and without the native
# authentication, they will not be able to connect to the database on NT.
SQLNET.AUTHENTICATION_SERVICES = (NTS)
And finnaly the tnsnames.ora for the 9i client connecting to the 10g database on the server (Windows 2003):
# TNSNAMES.ORA Network Configuration File: c:\ora9i\network\admin\tnsnames.ora
# Generated by Oracle configuration tools.
PROD.ORACLE =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = VICTORY)(PORT = 1521))
(CONNECT_DATA = (SERVICE_NAME = PROD.ORACLE))
)

Answer 1

hello, please try to comment the line in the sqlnet.ora file on the client and try again. If it works do the same on the server. Or you can set the value to NONE instead of (NTS).
Try this and let me know - this can be the reason why you cannot login without password as sysdba. When you are not using @ in sqlplus from the server these files are not read that's why it works.
If it does not work yet in the same file try adding the line:
NAMES.DIRECTORY_PATH= (TNSNAMES)
enrico