Local out traffic using ECMP routes could use different port or route to server

Starting from version 7.4.1, when there is ECMP routes, local out traffic may use different route/port to connect out to server. For critical traffic which is sensitive to source IP addresses, it is suggested to specify the interface or SD-WAN for the traffic since FortiOS has implemented interface-select-method command for nearly all local-out traffic.

config system fortiguard
    set interface-select-method specify
    set interface "wan1"
end