I have installed Oracle provider for OLE DB (OraOLEDB) 11.2.0.1.0 on a server to allow our SIEM to connect to our customer's Oracle DB 10G R2 for monitoring purpose.
However, I'm still getting error saying "ORA-12541: TNS:no listener" when I test the connection to the DB.
I have tested the Oracle OLE Provider driver via Microsoft ODBC Data Source and it returned "Connection successful". Apart from this, I also did a tnsping on the DB and it returned "OK" and the tnsnames.ora is configured according to the one on the DB.
My question is could this issue be due to the OLE DB provider 11.2.0.1.0 is not compatible with Oracle DB 10G R2.
I really hope to hear from you as I have ran out of idea on the solution.
Thank you.
If there was a version compatibility issue, you'd see a different error message.
You can see some docs here about cross-version authentication issues in some versions.
https://docs.oracle.com/cd/B28359_01/network.111/b28317/sqlnet.htm#NETRF196 But ORA-12541: TNS:no listener is when we can't get a response on the port we're reaching out to. This also means we are *finding* a tnsnames.ora file to use (because if we could not, we'd get a "cannot resolve name" error).
Since you're sure that the tnsnames.ora is correctly configured, I'd perhaps suspect that we're picking up a different one.
I'd look at doing a sqlnet trace to diagnose what files it is picking up and what parameters are being used to head out across the network.
AMIS have a nice simple writeup of sqlnet tracing here
https://technology.amis.nl/2014/08/26/sqlnet-tracing-nightly-hours/