ORA-28040: No matching authentication protocol exception

This is a quick post to resolve ORA-28040 & ORA-03134, specially if you have recently upgraded to 12c. ORA-28040: No matching authentication protocol error. ORA-03134: Connections to this server version are no longer supported error. Actually from 12c the default setting for allowed logon version is 11, that means by default you can only connect…