Lower UCS infra firmware version does support higher UCS-B series firmware?

[mate.fekete]

I have UCSB200 M5 blade with 4.0(4c) B series bundle package and I should move that blade to another UCS domain which is running on 3.2(2d) infra version.

Will it work at all?

The M5 blade is operational in a domain which is on 4.0(4c) infra version.

[Kirk J]

So, from official UCSM support cross support matrix perspective, that is not supported. See https://www.cisco.com/c/en/us/td/docs/unified_computing/ucs/release/notes/CiscoUCSManager-RN-4-0.html#concept_rlp_4h2_zdb

The board controller will not let you downgrade it, but the rest of the components (assuming you don't have any 4.0 minimum version requirements for any of the blade hardware) can be downgraded.

Basically you can up-rev your blade/rack bundles as long as the major version is still the same (i.e. UCSM 3.22 can handle 3.23, but not 4.x bundles)

Kirk...