How to upgrade firmware FGT200D Using the HA Active-Active

You can log in via GUI to the cluster (not to the master, in case you have mgmt ports configured), and initiate the upgrade. The cluster master will schedule the upgrade for the slave first, reboot it, fail over and upgrade itself.

There is not much you need to configure before starting. I would recommend (as FTNT) to disable HA port monitoring during the process.

Of course, keep an image of the currently running firmware at hand, as well as the current backup - for both master and slave (here the mgmt ports comes in...), and please, READ the Release Notes. Check what's changed and dependencies towards FortiClient, FortiMail, FortiSandbox, FortiAnalyzer, FortiAP.

The easiest way is to login from GUI on master and upload firmware. Master will first upgrade the subordinary unit, the subordinary will reload, then the master will upgrade and then reload.

Considerations you need to examine:

Read release notes especially when upgrade path is needed.

Preemtion settings : (set override enable | disable)

session sync settings : (session-pickup {disable | enable})

Also its good to have console access (not only ssh) during upgrade to see the output.

You need first to read the release notes and the upgrade guide, and / or upgrade path

then you take config backup

then uploade FortiOS on Primary. Primary will itself first upgrade the secondary, the secondary will reload, then the primary will upgrade, reload, finish.