OMS 12c : 12.2 ASM / Database /Grid Infrastructure Targets are Shown as Down
But in the target page it will be shown as down with the below error
ORA-28040: No matching authentication protocol
The same occurs for ASM and cluster targets too.
This is because 184.108.40.206 OMS is certified to monitor only DB versions below 220.127.116.11.
1. For monitoring 12.2 DB and related targets, OMS needs to be at least of 18.104.22.168 release with 22.214.171.124 DB plugin.
2. If this issue occurs in 126.96.36.199 release too, ensure that the latest DB and Agent bundle patches are applied at the Agent.