Typically for a FortiGate HA (High Availability) Cluster, you would require two licenses, one for each FortiGate unit in the cluster.
This is because the HA Cluster involves two physical FortiGate devices that are configured to work together to provide redundancy in case of a failure of one unit. Each FortiGate unit requires its own license to operate, and both units need to be licensed with the same feature set and subscription term.
It's important to make sure that both FortiGate units have valid licenses for the same features and subscription term to ensure that they can synchronize and operate properly as an HA Cluster.
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