Hi, thanks for the query.
What`s the discovery type used for discovering these devices in OME? Basically, second page in discovery wizard where device type filtering is done.
1) If iDRAC`s were discovered using other than below highlighted Device Type in OMEv2.x, then due to OMEv2.3`s default behavior of “Device Type based discovery”, post upgrade & re-discovery those iDRAC devices will be unclassified/unknown. Hence the status changes from previous state to unknown.
I would request you to check the filter settings on your discovery ranges and ensure they match the type of devices available on them.
2) Another way would be to ignore this setting globally for all your discovery and keep the behavior same as of OME 2.x < OME 2.3. Navigate to Settings -> Discovery Settings and un-check "Discover the selected Device Types only" checkbox.
Let us know if this is helpful.