Measured Volume: Traffic is load balance based on traffic and volume, more traffic is sent to interface with higher volume ratios.Source Destination IP : All traffic from Source IP to destination IP is sent to the same.Usage: All traffic is sent to first interface on the list, when the bandwidth on that interface exceeds the spillover limit new traffic is sent to next interface.

Weight: Interface with higher weights have higher priority.

Source IP: All traffic from the source IP is sent to the same interface.

But this can be changed to any of the following methods based on: SD-WAN load balancing uses traffic distribution that is like ECMP, however SD-WAN link load balancing includes one more balancing method volume, by default the load balancing mode is set to Source IP based. Another important feature is link quality measurement, using ping or http echo FortiGate can determine latency, jitter or packet loss percentage for each link and dynamically select links based on these capacities, this guarantees high-availabilityHA for commercial-critical applications. SD-WAN is mainly used when multiple WAN links are used and effective WAN usage is achieved using various log balancing methods, such as bandwidth usage, session, or application over routing. One SD-WAN interface per VDOM is preferable. Using SD-WAN simplifies configuration for administrators who can configure a single set of routes and firewall policies and deploy them to all member interfaces. SD-WAN is a virtual interface which connects different link types using a group of member interfaces.

Fortinet sd wan