Pass the Fortinet Network Security Expert NSE6_SDW_AD-7.6 Questions and answers with ExamsMirror

This configuration demonstrates a typical IPsec setup for SD-WAN overlays where the hub side requires a manually defined tunnel IP address, and the spoke can be flexibly configured, including interoperability with third-party IPsec devices. As described in the Fortinet SD-WAN Architect Guide: “For some overlays, the tunnel interface IP is configured statically on the hub side, which allows more control over overlay subnetting and facilitates the use of user-defined overlay IP addresses. This approach is also a requirement for compatibility with non-FortiGate endpoints, such as third-party IPsec devices that may not support dynamic address assignment via IKE or proprietary mechanisms.” This enables hybrid SD-WAN environments and advanced designs involving external partners or cloud services. Overlay IP flexibility is critical for route control and segmentation.

Event logs (from the exhibit) show how traffic is matched to SD-WAN rules and routed. The log output indicates that voice traffic is being routed through the HUB1-VPN3 tunnel. This matches SD-WAN's application-aware steering, which uses dynamic performance metrics to select the optimal path.

In the exhibits, port2 is already assigned to the SD-WAN zone named Test. An interface can only belong to a single SD-WAN zone, so before you can add both port1 and port2 into the new SD-WAN zone Underlay, you must first delete the SD-WAN Zone Test to free port2.

From the Underlay and network advertisement configuration exhibit for the Secondary HUB:

Under Underlay, the template explicitly lists:

WAN Underlay 1 = port1

WAN Underlay 2 = port2

In FortiManager SD-WAN Overlay Orchestrator, underlay interfaces selected for a hub are the transports used to build the overlay IPsec tunnels (one overlay per underlay, per peer as defined by the template). Because both port1 and port2 are configured as underlays, FortiManager will build overlay tunnels over both underlay links. That supports:

Option C (overlay tunnel on port1)

Option B (overlay tunnel on port2)

For the BGP neighbor options:

The Network Advertisement section shows Interface 1 = port5, which indicates a LAN/internal interface whose connected or static networks may be advertised into the overlay routing domain. This does not make port5 a BGP neighbor interface; it is the interface whose routes are being advertised.

The template indicates Dynamic BGP is enabled. In Overlay Orchestrator designs, BGP neighbor relationships are formed across the overlay tunnel interfaces / overlay endpoints, not directly on the raw underlay interfaces (port1/port2) and not on the advertised LAN interface (port5). Therefore, options A and D are not valid conclusions from what is shown.

So, the two correct conclusions are B and C.

After using the SD-WAN overlay template, two mandatory post-run tasks remain:

"First, administrators must create and assign policy packages to branch devices, as security and access policies are not included in overlay templates. Second, SD-WAN rules must be configured so that traffic can be matched and steered appropriately through the established overlays. Neglecting either task results in ungoverned traffic or inefficient routing, undermining the benefits of SD-WAN."

Templates automate topology, but policy and rule definition are critical for operational effectiveness.

In the SD-WAN GUI, the absence of members in a zone is visually represented, and the Fortinet guide confirms:

"If a zone such as overlay-factories contains no members, it will be displayed as empty in the SD-WAN GUI. This may occur when the zone is reserved for future expansion, or if members have been temporarily removed for maintenance or reconfiguration. Traffic cannot be steered via an empty zone until at least one SD-WAN member is added."

Such visual cues help operators quickly assess configuration status and readiness.

In FortiOS 7.6, when SD-WAN is enabled, physical and logical WAN interfaces are added as SD-WAN members and are abstracted behind the SD-WAN interface (virtual-wan-link or SD-WAN zone) . Traffic forwarding decisions are then made by SD-WAN rules instead of individual interfaces.

As documented in the FCSS SD-WAN 7.6 curriculum and Fortinet SD-WAN architecture guides, firewall policies must reference the SD-WAN interface or SD-WAN zone , not the individual WAN interfaces that are members of SD-WAN. Therefore, during the configuration update process, existing firewall policies that reference physical WAN interfaces must be updated to reference the SD-WAN interface .

Option A is incorrect because routing configuration does not require replacing interface references when SD-WAN is enabled. Static and dynamic routes typically point to the SD-WAN interface automatically, and SD-WAN rules handle path selection.

Option B is incorrect because SD-WAN is a built-in FortiOS feature . It does not require a separate license and does not require a reboot when enabled.

Option D is incorrect because interfaces must remain enabled to function as SD-WAN members. Disabling an interface would prevent SD-WAN from using it for traffic forwarding.

Therefore, the required action during the SD-WAN configuration update process is to replace references to interfaces used as SD-WAN members in the firewall policies , which corresponds to option C.

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

SD-WAN rules If 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.

Drop If 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 .