Source prefixes

If a FortiGate has more than one management IP address and default route, packets can’t differentiate between them and may reach the wrong management IP address. To avoid this, you can configure a source prefix that allows the FortiGate to differentiate between multiple default routes.

To configure source prefixes - CLI

config router static

edit <sequence number>

set gateway <IP address>

set src <source prefix>

next

edit <sequence number>

set gateway <IP address>

set src <source prefix>

next

end