Connections Via a 9i Listener to a 10g Instance Fail With ORA-12500

(Doc ID 271179.1)

Last updated on OCTOBER 27, 2016

Applies to:

Oracle Net Services - Version: 10.x
This problem can occur on any platform.


1) You have a 10gRx version of the database

2) On the same server, you have 9.2.x listener running.

3) Remote client connections via the listener fail with ORA-12500 errors. 

4) The listener.log shows:

TNS-12500: TNS:listener failed to start a dedicated server process


It is likely this is a new installation of 10g in an environment where only 9i existed previously.


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