원문 : http://www.ischo.net -- 조인상 //시스템 엔지니어
28040, 0000, "No matching authentication protocol"
// *Cause: There was no acceptable authentication protocol for
// either client or server.
// *Action: The administrator should set the values of the
// SQLNET.ALLOWED_LOGON_VERSION_SERVER and
// SQLNET.ALLOWED_LOGON_VERSION_CLIENT parameters, on both the
// client and on the server, to values that match the minimum
// version software supported in the system.
// This error is also raised when the client is authenticating to
// a user account which was created without a verifier suitable for
// the client software version. In this situation, that account's
// password must be reset, in order for the required verifier to
// be generated and allow authentication to proceed successfully.
원인 : 서버/클라이언트간 인증 프로토콜 차이
서버의 sqlnet.ora 파일에
SQLNET.ALLOWED_LOGON_VERSION = 9