failed to set up cluster after upgrading from v10.2.4 to v11.4.1

We recently upgraded a pair of lesser appliances from 10.2.2 HF3 (Partitions) to 11.4.1 HF3. Our high-level procedure that was reviewed and modified by F5 consulting services was this:

1. Disconnect Standby Device

    

2. Rebuild Standby Device with v10.2.2 media (Volumes)

    

3. Renew device certificate with expiration of 10 years.

    

4. Load volume 1.2 with 10.2.2 HF3 and load volume 1.3 with 11.4.1 HF3

    

5. Boot to volume 1.2 and import config from UCS file (fall-back volume)

    

6. Boot to volume 1.3 and migrate config from volume 1.2 (dropdown menu selection)

    

7. Disable interfaces on active device; enable interfaces on newly rebuilt device (essentially a manual failover).

    

8. Rebuild device that is now standby using same procedure, EXCEPT when you boot to volume 1.3 you DO NOT migrate the config.

    

9. When offline/standby device boots to 11.4.1 HF3 build network components manually to match required configuration.

    

10. Renew device certificate with expiration of 10 years.

     

11. Build device trust/peer list from scratch and create device group for sync/failover.

     

I've never seen anyone say they migrated from v10.2.2 or earlier to v11.x without having to completely rebuild the device trust and pair the devices up from scratch. Hope this helps. If you have specific questions about the device trust/device group/peer list process what are they?