After upgraded an Oracle database from 11.2.0.4 to 12.2.0.1 I receive the error “ORA-28040: No matching authentication protocol exception” during one of our applications tried to connect to this database. This is due to the fact that in version 11G the parameter SQLNET.ALLOWED_LOGON_VERSION_SERVER had the default value 8 while in version 12c it is 11. Knowing this, after changing the value of the parameter in the sqlnet.ora file the problem has been solved.
Portuguse / Português
Depois de atualizar um banco de dados Oracle 11.2.0.4 para 12.2.0.1 eu recebir o erro “ORA-28040: No matching authentication protocol exception” durante uma de nossas aplicações tentou se conectar a esta base dados. Isto se deve ao fato de na versão 11G o parâmetro SQLNET.ALLOWED_LOGON_VERSION_SERVER tinha o valor padrão 8 enquanto que na versao 12c é 11. Sabendo disso, após a alteração do valor do parâmetro no arquivo sqlnet.ora o problema foi resolvido.
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Hello, I’m Bruno — a dual citizen of Brazil and Sweden. I bring a global perspective shaped by experiences in both South America and Europe, with a strong focus on collaboration and innovation across cultures. I am a Computer Scientist, PhD Candidate in Information and Communication Technologies, focusing on Data Science and Artificial Intelligence, and hold dual Master’s degrees in Data Science and Cybersecurity. With over fifteen years of international experience spanning Brazil, Hungary, and Sweden, I have collaborated with global organizations such as IBM, Playtech, and Oracle, as well as contributed remotely to projects across multiple regions. My professional interests include Databases, Cybersecurity, Cloud Computing, Data Science, Data Engineering, Big Data, Artificial Intelligence, Programming, and Software Engineering, all driven by a deep passion for transforming data into strategic business value.