FCSS_SDW_AR-7.6 Fortinet Exam Lab Questions

In FortiOS (including FortiOS 7.6), FortiGate follows a strict and well-defined route lookup order when determining how to forward traffic. This order is critical for understanding SD-WAN behavior and is explicitly referenced in the FCSS SD-WAN curriculum.

The correct lookup sequence is:

Policy routes (Policy-Based Routing)Policy routes are evaluated first. If traffic matches a policy route, FortiGate immediately forwards the traffic according to that policy and bypasses all other routing mechanisms.

Internet Service Database (ISDB) routesIf no policy route matches, FortiGate checks ISDB routes. These routes match traffic based on Internet Services rather than destination IP prefixes.

SD-WAN rulesIf neither a policy route nor an ISDB route matches, FortiGate evaluates SD-WAN rules to determine the outgoing interface based on the configured SD-WAN strategy.

Routing table (connected, static, and dynamic routes such as BGP)If no SD-WAN rule matches, FortiGate performs a normal routing table lookup.

FIB (Forwarding Information Base)The FIB is used to forward the packet based on the selected route.

DropIf no valid route exists, the packet is dropped.

Among the options provided, only Option D correctly reflects the beginning of this sequence by placing policy routes first, followed by ISDB routes, then SD-WAN rules, and finally static routes (representing the routing table).

Therefore, the correct answer is D.

When the member priority of a port is increased (e.g., port2 to 20), FortiGate evaluates existing sessions and applies “dirty” flags where applicable. The SD-WAN session management mechanism is described in detail: “Upon a change in SD-WAN member priority, all existing sessions using that member are marked as dirty. For SNAT sessions, the gateway information is updated to ensure future packets are routed through the newly preferred member, in this case, port1. This automatic re-evaluation allows SD-WAN to dynamically respond to topology or priority changes, maintaining optimal routing.” This is fundamental to seamless failover and session persistence in Fortinet SD-WAN, ensuring active flows are redirected based on updated priorities or health status.

One SD-WAN rule is defined with application categories as the destination → The diagnose output shows application control matches such as Microsoft.Portal, Operational.Technology, and Social.Media, confirming that SD-WAN rules are using application categories as destinations.

UDP traffic destined to the subnet 10.22.0.0/24 matches a policy route → The first entry (id=1) shows protocol=17 (UDP) with destination 10.22.0.0/24, confirming this traffic is handled by a policy route instead of an SD-WAN rule.