Thanks for the question, Anna.
Asked: May 16, 2025 - 9:25 am UTC
Last updated: May 19, 2025 - 7:38 am UTC
Version: 19.10
Viewed 1000+ times
You Asked
Hello ,
Hello, I'm having a rather strange problem:
A single Windows user is unable to connect to a database hosted on the WINDOWSPROD server. The error is: ORA-12637: Unable to receive packet; in the alert.log:
ORA-00609: Could not attach to incoming connection
ORA-12699: Native service internal error
The same user can connect to the database hosted on the WINDOWSPROD server. Both servers are in the same domain.
Does anyone have any ideas?
and Connor said...
A couple of possibilities to explore
"ORA-12637: Unable to receive packet" is most typically due to firewall or similar that is blocking inbound from the database back to the client.
"ORA-12699: Native service internal error" can be due to a conflict in encryption settings between server and client (check the sqlnet.ora)
In the latter case, it can also be due to outdated client software, so make sure you're using an up to date oracle client (this is easy to verify by downloading the instantclient packages, and then doing a test with the instantclient on the PATH)
If you are still stuck, collect a detailed level SQLNet trace (see MOS Doc ID 219968.1) and then raise a call with Support with that trace.