FCSS_SDW_AR-7.6 Exam Dumps - FCSS - SD-WAN 7.6 Architect

FortiManager enforces a strict distinction:

"Firewall policies must reference SD-WAN zones, not individual SD-WAN members, when used in conjunction with SD-WAN templates. Attempting to install a policy that references a specific member (interface) will result in a deployment error, as member-level targeting is not supported in SD-WAN policy abstraction. This enforces centralized policy consistency and proper SD-WAN operation."

Ensuring policies target zones allows FortiGate to dynamically select the optimal member.

The router policy explicitly denies traffic with source 10.0.1.128/25 (which includes 10.0.1.130) and destination 128.66.0.0/24 (which includes 128.66.0.125). Even though SD-WAN service 4 shows members (port1 and port2) alive and available for this traffic, the router policy is evaluated first and blocks it. Therefore, FortiGate drops the traffic flow.

The line sdwan_mbr_seq=1 sdwan_service_id=4 indicates that this session is part of an SD-WAN rule. sdwan_service_id=4 confirms that the session is being handled by SD-WAN rule ID 4. This directly links the flow to the SD-WAN configuration.

The line no_offload_reason: redir-to-ips denied-by-nturbo shows that the session is not offloaded to the NPU (Network Processing Unit) and is being processed by the main CPU. A session that is not offloaded can be re-evaluated. If the outgoing interface (the one currently being used) goes down, the FortiGate will re-evaluate the session against the SD-WAN rules to find a new active member to steer the traffic through. This is a fundamental behavior of SD-WAN, which ensures network resilience.

The rule is in SLA mode with two SLAs. From the status, HUB1-VPN2 and HUB1-VPN3 meet the SLA (sla(0x2) and sla(0x3)), while HUB1-VPN1 does not (sla(0x0)). Among members that meet SLA, FortiGate uses the configured order (priority-members 4 5 6) to pick the first eligible one—HUB1-VPN2—so traffic is routed over HUB1-VPN2.

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.