This article describes why a static route or default route outgoing with SD-WAN Zone cannot be assigned an administrative distance of 10 on a FortiGate.
Scope
FortiGate.
Solution
The following example explains that a static route or default route pointing to an SD-WAN zone cannot set a distance of 10.
By default, the SD-WAN routes distance value is set to ‘1’.
When trying to change the SD-WAN route distance value to 10, the change will not take effect, and the value will revert back to 1.
SD-WAN route can be assigned any administrative distance value between 1 and 255, except AD value 10. Because distance 10 is the default value for static routes, it cannot be assigned to SD-WAN routes.
It is the default behavior on FortiGate that it is impossible to assign a distance value of 10 to an SD-WAN route.