According to the FortiOS 7.6 Study Guide and technical documentation regarding High Availability (HA), the FortiGate Clustering Protocol (FGCP) uses a specific set of rules to elect the primary unit in a cluster. By default, the election order follows: Connected Monitored Ports > HA Uptime > Priority > Serial Number.
However, when the HA override setting is enabled, the election logic is modified to prioritize the administrator-defined priority value over the uptime of the cluster members. In this specific configuration, the election process follows this sequence:
Connected monitored ports: The unit with the most functioning monitored interfaces is preferred.
Priority: The unit with the highest manually configured priority value (e.g., 255) is selected next.
HA uptime: If monitored ports and priority are equal, the unit that has been up in the HA cluster the longest is chosen.
FortiGate serial number: As a final tie-breaker, the unit with the higher serial number is elected.1
Statement A is correct because it reflects the shift where Priority is evaluated immediately after monitored ports, overriding the standard uptime advantage. Statements B and D are incorrect because the FGCP uses HA uptime, not system uptime, for its calculations.