Hello,

after 2 days of fruitless searching and trying, I'm nearly desperate now,
so I'm posting my problem here with hope that someone can help...

I'm trying to connect to an Oracle 9.2 database via TCP from Microsoft
Access 2000 SP3.
I'm using the ODBC-Drivers from Microsoft.

I keep getting the following error:
"[Microsoft][ODBC driver for Oracle]ORA-12535: TNSperation timed out
(#12535) [Microsoft][ODBC Driver Manager] Fehler bei SQLSetConnectAttr für
Treiber (#0)"


Here are the details:

CLIENT-machine:
Operating system: Microsoft Windows 2000 SP4
ODBC-Driver: Microsoft ODBC for Oracle V2.575.1062.00
Client-Database: Microsoft Access 2000 SP3
Oracle: Oracle 9.2.0.1.0

SERVER-machine:
Operating system: Microsoft Windows Server 2003 SP1
Oracle: Oracle 9.2.0.1.0

--------------------------------------------------------------
tnsnames.ora (CLIENT)
---------------------
ORACLE.EMBITBIZ =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 217.69.83.130)(PORT = 1521))
)
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = MBDaten)
)
)
--------------------------------------------------------------
listener.ora (SERVER)
---------------------
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = embit)(PORT = 1521))
)
)
)

SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = c:\oracle\ora92)
(PROGRAM = extproc)
)
(SID_DESC =
(GLOBAL_DBNAME = mbdaten)
(ORACLE_HOME = c:\oracle\ora92)
(SID_NAME = mbdaten)
)
)

--------------------------------------------------------------
sqlnet.ora (SERVER)
---------------------

NAMES.DEFAULT_DOMAIN = biz

SQLNET.AUTHENTICATION_SERVICES= (NTS)

#NAMES.DIRECTORY_PATH= (TNSNAMES)
NAMES.DIRECTORY_PATH= (TNSNAMES, ONAMES, HOSTNAME)
--------------------------------------------------------------


- I have installed Microsoft MDAC 2.8 SP1 on the client-PC

- I have changed registry settings, as suggested by many websites to the
following values:

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSDTC\MTxOCI]
"OracleXaLib"="oraclient9.dll"
"OracleSqlLib"="ORASQL9.DLL"
"OracleOciLib"="oci.dll"

- "tnsping ORACLE.EMBITBIZ" on the client-machine reports success:

Adapter TNSNAMES zur Auflösung des Alias benutzt
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL
= TCP)
(HOST = 217.69.83.130)(PORT = 1521))) (CONNECT_DATA = (SERVER = DEDICATED)
(SERV
ICE_NAME = MBDaten)))
OK (40 ms)

- The listener.log on the SERVER shows that the listener configuration
should be OK, as the connection seems to be established correctly:
18-AUG-2006 13:04:18 *
(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=MBDa ten)(CID=(PROGRAM=C:\WINNT\system32\odbcad32.exe)( HOST=MBINTERN)(USER=Administrator
))) * (ADDRESS=(PROTOCOL=tcp)(HOST=212.202.134.67)(PORT= 58954)) *
establish * MBDaten * 0

- The user I'm using for Login is able to connect to the database (as
tested with SQL+ Worksheet on the SERVER-machine)


I suppose the problem to be connected with the ODBC-driver on the client
machine.

I don't know anything else to do or try to solve this problem.
Can anybody help me ?! Any suggestions or tips?