Fortinet 400 manual Least Connection, Weighted Round Robin

High availability HA in NAT/Route mode

4Select the HA mode.

Select Active-Passive mode to create an Active-Passive HA cluster, in which one FortiGate unit in the HA cluster is actively processing all connections and the others are passively monitoring the status and remaining synchronized with the active FortiGate unit.

Select Active-Active mode to create an Active-Active HA cluster, in which each FortiGate unit in the HA cluster is actively processing connections and monitoring the status of the other FortiGate units.

The HA mode must be the same for all FortiGate units in the HA cluster.

5Enter and confirm a password for the HA cluster.

The password must be the same for all FortiGate units in the HA cluster.

6Select a Group ID for the HA cluster.

The Group ID must be the same for all FortiGate units in the HA cluster.

7If you are configuring Active-Active HA, select a schedule.

The schedule controls load balancing among the FortiGate units in the active-active HA cluster. The schedule must be the same for all FortiGate units in the HA cluster.

None	No load balancing. Select None when the cluster interfaces are
	connected to load balancing switches.
Hub	Load balancing for hubs. Select Hub if the cluster interfaces are
	connected to a hub. Traffic is distributed to units in a cluster based on
	the Source IP and Destination IP of the packet.
Least Connection	Least connection load balancing. If the FortiGate units are connected
	using switches, select Least connection to distribute traffic to the cluster
	unit with the fewest concurrent connections.
Round Robin	Round robin load balancing. If the FortiGate units are connected using
	switches, select round robin to distribute traffic to the next available
	cluster unit.

Weighted Round Robin

Weighted round robin load balancing. Similar to round robin, but weighted values are assigned to each of the units in a cluster based on their capacity and on how many connections they are currently processing. For example, the primary unit should have a lower weighted value because it handles scheduling and forwards traffic. Weighted round robin distributes traffic more evenly because units that are not processing traffic will be more likely to receive new connections than units that are very busy.

Random	Random load balancing. If the FortiGate units are connected using
	switches, select random to randomly distribute traffic to cluster units.
IP	Load balancing according to IP address. If the FortiGate units are
	connected using switches, select IP to distribute traffic to units in a
	cluster based on the Source IP and Destination IP of the packet.
IP Port	Load balancing according to IP address and port. If the FortiGate units
	are connected using switches, select IP Port to distribute traffic to units
	in a cluster based on the Source IP, Source Port, Destination IP, and
	Destination port of the packet.

FortiGate-400 Installation and Configuration Guide 79