While configuring a database (12.2) from OEM 12c, the database was added to the monitoring but the status of DB was showing down. And observed below error; also observed “INVALID USERNAME/PASSWORD” sometimes.
Failed to connect to database instance: Failed to connect: java.sql.SQLException: ORA-28040: No matching authentication protocol .
The monitoring password in DB could be an issue.
The resolution looks very strange. The username, password of DBSNMP were working fine, able to connect and access from OEM. Tried resetting DBSNMP password to the same password; but didnt help. Tried removing the target from OEM, clearing the state of em agent, emagent bounce etc didnt help. Observed that the user DBSNMP has a profile tagged; Thanks to my colleague Ameer for trying out in the below order and it fixed,
- Removed target from OEM
- Setting the profile of DBSNMP to default
- Password change (to the same pwd) and reassigned the original profile to user
- Added back the target to OEM and secure the agent