Fail-over | config Sync on F5

Hi,

Yes you can leave one appliance on 11.2.1 and the other on 11.6.1, but I would not advise that. Below a F5 statement:

"Note: When upgrading a device group from version 11.x, or later, software to the latest version software, mirroring does not function until all devices in the device group complete rebooting to the latest version."

So you must take into account sessions are lost during fail-over when both devices have different versions. Thats why F5 recommends a window when upgrading.

"F5 Networks® recommends upgrading software during a scheduled maintenance window, to minimize traffic disruption when devices run different software versions."

I have seen issues with sync when both devices have different software version, so I strongly advise to upgrade all devices in the same cluster to the same version.

On you can find plenty of information and documentation about upgrading Active/Standby cluster. Complete with all the steps that are needed.

And you should have good test procedures you can perform before and after the upgrade.

Good luck.

Martijn.