High availability (HA) is usually required in a system where there is high demand for little downtime. There are usually hot-swaps, backup routes, or standby backup units and as soon as the active entity fails, backup entities will start functioning. This results in minimal interruption for the users.
The FortiGate Clustering Protocol (FGCP) is a proprietary HA solution whereby FortiGates can find other member FortiGates to negotiate and create a cluster. A FortiGate HA cluster consists of at least two FortiGates (members) configured for HA operation. All FortiGates in the cluster must be the same model and have the same firmware installed. Cluster members must also have the same hardware configuration (such as the same number of hard disks). All cluster members share the same configurations except for their host name and priority in the HA settings. The cluster works like a device but always has a hot backup device.
The following are critical components in an HA cluster:
- Heartbeat connections: members will use this to communicate with each other. In general, a two-member cluster is most common. We recommend double back-to-back heartbeat connections.
- Identical connections for internal and external interfaces: as demonstrated in the topology, we recommend similar connections from each member to the switches for the cluster to function properly.
The following are best practices for general cluster operation:
- Ensure that heartbeat communication is present.
- Enable the session synchronization option in daily operation (see FGSP (session synchronization) peer setup).
- Monitor traffic flowing in and out of the interfaces.
FGCP provides failover protection in the following scenarios:
- The active device loses power.
- A monitored interface loses a connection.
After failover occurs, the user will not notice any difference, except that the active device has changed. See Failover protection for more information.