Hi all,

I have recently upgraded from to on a W2K box. The upgrade went through fine but i am gettin the above error when i try and connect like below from the 9i home using the 9i LISTENER to the upgraded 10g db (connecting without service name works fine from 9i to 10g):

sqlplus usn/pass@servicename

The sqlnet.log shows:
Tns error struct: 0
ns main err code: 12564
TNS-12537: TNS:connectio closed
ns secondary err code: 12560
nt main err code: 507
TNS-00507: connection closed
nt secondary err code: 0
nt OS err code: 0

The 507 implies:

Cause: An internal operation did not commence because to do so would block the current process and the user has requested that operations be non-blocking.

Action: None needed; this is an information message.

TNS-00507 Connection closed

However in this scenario what could be causing this to happen, as i get kicked out? I deleted the 9i Windows service and created a new one for 10g as part of the upgrade. As a workaround (will be the solution eventually) i created a 10g listener and this allowed me to connect fine to the 10g box. I can tnsping (9i utility) to the 10g db. Its only when I add the service name the error happens.

Any advice will be greatly appreaciated.

Thanks in advance,