F5 rSeries appliance firmware upgrade question

Yes, the license should be reactivated before an upgrade.

The operating system on a BIG-IP devices in know as TMOS (Traffic Management Operating System).

Newer version of TMOS will check the version and timestamps in the license file. My rule of thumb is to update, reactive license, before any TMOS upgrade.  

The affected devices need to be covered by the initial warranty or a support contract.  This coverage allows the new license file to have the correct timestamps and version for the new version of TMOS. 

My High level upgrade steps for a pair redundant BIG-IP devices:

1. Upload new TMOS image. Can be done before upgrade change window.
2. Download configuration archives from the device being upgraded, UCS files.
3. Install new license on standby device, alpha.
4. Reboot the alpha device.
5. On alpha. Install new TMOS version to a volume / boot location.
6. Reboot alpha into new TMOS version. ROLL CONFIGURATION FORWARD.
   1. Select configuration from the current volume / boot location.
7. Wait for alpha to reboot.
8. Verify alpha booted correctly into the new TMOS version.
9. Force the active device , beta, to be the standby device.
   1. When using HA groups the beta device should be taken online.
10. Verify alpha is the active device.
11. Install new license on standby / offline device, beta.
12. Reboot the beta device.
13. On beta. Install new TMOS version to a volume / boot location.
14. Reboot beta into new TMOS version. ROLL CONFIGURATION FORWARD.
    1. Select configuration from the current volume / boot location.
15. Wait for beta to reboot.
16. Verify beta booted correctly into the new TMOS version.
17. Verify beta is the standby device.
    1. If beta is off line. Bring beta online.
18. Verify the Device service clustering (DSC) status.

19. Test synchronization

    1. Make a change on alpha.
    2. Verify change propagated to beta.

    3. Make a change 0n beta.

    4. Verifiy change propagated to alpha.

20. Redundancy testing
    1. Make alpha standby.
    2. Wait a at lest 5 minutes.
    3. Make sure that beta stays the active device and alpha the standby device.
    4. Make beta the standby device.
    5. Make sure that alpha stays the active device and beta the standby device.

21. Make the preferred device the active device.

22. BIG-IP DNS / GTM Client .........

23. Verify iQuery with monitoring BIG-IP DNS devices.

Semantics:

TMOS is not firmware. It's an operating system. When booting in a version of TMOS. There is a process that checks the version of installed hardware firmware. When a different version of hardware firmware is required. It gets installed. The BIG-IP can reboot after a firware install. Booting in to a different version of TMOS can require multiple reboots due to firmware installs. 

-Matt