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ORA-12547 While Client Connecting Via SSH Tunnel (Doc ID 454252.1)

Last updated on FEBRUARY 21, 2020

Applies to:

Oracle Net Services - Version to [Release 9.2 to 10.2]
Information in this document applies to any platform.
This problem can occur on any platform.


Client connection via SSH Tunnel fails  with ORA-12547  with IP Filter (TCP Valid Node checking)  enabled on the database server.

ie, even if the client IP address is listed in the tcp.invited_nodes , when the client connects via the SSH Tunnel (with port forwarding enabled on the client side) it errors with ORA-12547.

#sqlplus <username>/<password>@<SSH>

ORA-12547: TNS:lost contact


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