Error "ORA-28040: No matching authentication protocol" After database upgrade to 12c

(Doc ID 755605.1)

Last updated on APRIL 25, 2018

Applies to:

Oracle Net Services - Version to [Release 12.2]
JDBC - Version 10.1.0 to
Information in this document applies to any platform.


When using the property "SQLNET.ALLOWED_LOGON_VERSION=10" set in the file sqlnet.ora on the server side, a 10g JDBC thin driver connecting to this 10g oracle database, fails with following errors:

The Network Adapter could not establish the connection
ORA-28040: No matching authentication protocol



Database upgrade to latest version, or configuring SQLNET.ORA on the server side.


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