When SD-WAN is enabled on FortiGate, the load balancing algorithm for Equal-Cost Multi-Path (ECMP) is configured using the load-balance-mode parameter under SD-WAN settings. However, if SD-WAN is disabled, the ECMP load balancing algorithm can be configured under config system settings. This flexibility allows FortiGate to control traffic routing behavior based on the network configuration and requirements.
References:
* FortiOS 7.4.1 Administration Guide: ECMP Configuration