In a FortiGate High Availability (HA) cluster on Azure, synchronization of configuration and session information between the active-active nodes is fundamental. This is achieved by configuring the FortiGate Clustering Protocol (FGCP), which is Fortinet's proprietary HA protocol responsible for state synchronization. For FGCP to function, dedicated heartbeat interfaces must be configured. These interfaces provide the communication path over which the synchronization traffic and heartbeat packets are exchanged between the cluster members. Therefore, configuring both FGCP settings and the heartbeat interfaces are the direct and essential tools for enabling synchronization.

B. Autoscale: Autoscale is a cloud-native scaling solution, a different architecture from the two-node active-active HA cluster shown. It manages the number of instances, not their state synchronization. D. Software-defined network (SDN) Fabric Connector: The SDN connector is used for failover orchestration. It makes API calls to Azure to update route tables or move IP addresses, but it does not handle the state synchronization between FortiGate peers. E. FortiManager: While FortiManager can be used to apply the configuration, it is an optional, centralized management platform. The fundamental mechanisms being configured are FGCP and heartbeat interfaces, which are intrinsic to FortiOS.

1. Fortinet Documentation (FortiGate-VM on Azure Administration Guide): In the section on

configuring active-active HA, the guide explicitly states, "You must configure HA settings on both

FortiGates. This allows the FortiGates to operate in active-active mode and synchronize their

configurations. You must also select the heartbeat interfaces." This directly links the HA protocol

(FGCP) and heartbeat interfaces to synchronization.

Source: Fortinet Docs, FortiGate-VM on Azure 7.4.2 Administration Guide, Section: "Configuring

FortiGate HA for active-active HA".

URL: https://docs.fortinet.com/document/fortigate-vm-azure/7.4.2/administration-guide/525620/co

nfiguring-fortigate-ha-for-active-active-ha

2. Fortinet Documentation (FortiOS Administration Guide): The general HA guide defines the

roles of FGCP and heartbeat interfaces. "The FortiGate Clustering Protocol (FGCP) is a

proprietary HA protocol... The primary unit synchronizes its configuration with all subordinate

units... A FortiGate cluster communicates by sending HA heartbeat packets over the configured

HA heartbeat interface(s)."

Source: Fortinet Docs, FortiOS 7.4.4 Administration Guide, Section: "HA".

URL: https://docs.fortinet.com/document/fortigate/7.4.4/administration-guide/97232/ha