Fortinet FCSS_SDW_AR-7.6 FCSS - SD-WAN 7.6 Architect Exam Practice Test

The implicit SD-WAN rule serves as the final catch-all. Per Fortinet:

"Sessions matching the implicit SD-WAN rule do not have an SD-WAN service id, as they are not associated with any specific user-defined SD-WAN rule. Additionally, this occurs only when traffic fails to match any entry in the policy route table. This default handling guarantees connectivity while minimizing the risk of blackholed traffic."

Administrators can observe this in diagnostic outputs for troubleshooting.

In Fortinet SD-WAN architecture, underlay and overlay have distinct meanings:

Underlay links are the physical or logical transport networks that provide basic IP connectivity (for example, broadband, MPLS, LTE/5G).

Overlay links are virtual tunnels (such as IPsec VPNs) built on top of the underlay, providing abstraction, routing control, and segmentation.

Option B is correct.

Overlay links (for example, IPsec tunnels used in SD-WAN and ADVPN) decouple routing from the physical transport. This allows dynamic path selection, segmentation, and flexible routing policies independent of the underlay. Providing routing flexibility is a core purpose of overlays in SD-WAN.

Option D is correct.

Wireless connections such as LTE or 5G can be used as underlay transports, and overlay tunnels can be built over them. Fortinet SD-WAN fully supports building IPsec overlays on wireless underlays, making wireless links valid for overlay construction.

Why the other options are incorrect:

Option A is incorrect because a VLAN is a Layer 2 segmentation mechanism, not an SD-WAN overlay link.

Option C is incorrect because FortiLink is used for internal management and switch/AP connectivity, not as a WAN underlay for SD-WAN.

Option E is incorrect because underlay links can be wired or wireless; they are not limited to wired connections.

Therefore, the two correct statements are B and D.

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.

The FortiManager SD-WAN overlay template preview, as described in the document, indicates:

"When the device is acting as a hub, the configuration enables the sending of ADVPN shortcut offers to spokes. This means the hub can facilitate on-demand dynamic shortcut tunnel creation between spokes, improving performance for branch-to-branch communication by bypassing the hub for inter-branch traffic after initial discovery."

Such a role is critical in scalable ADVPN topologies, enabling hub devices to optimize overlays dynamically.

Policy 3 points traffic To = HUB1-VPN1, which is an SD-WAN member interface. In SD-WAN you must reference the SD-WAN zone (the logical interface) in policies, not its member tunnels. Change the policy’s To interface to the zone HUB1, and the install will succeed.

When asymmetric routing is observed (such as reply traffic not following the optimal path), the solution is:

"The auxiliary-session feature, enabled under config system settings, allows FortiGate to consider multiple egress interfaces for reply traffic, not just the original ingress interface. This is crucial for SD-WAN environments where the best path may differ between forward and return directions, especially when performance or policy rules are dynamically evaluated."

Activating this ensures reply traffic is always sent on the member with the best real-time metrics.

Rules template → Defines the SD-WAN rules for traffic steering.

BGP template → Configures dynamic routing for overlay tunnels.

IPsec tunnel template → Builds the IPsec VPN tunnels from the spoke to the hubs.

When using the diagnose sys session list command, SD-WAN-specific session steering is indicated by the presence of the sdwan_service_id field in the session data. This identifier ties the session directly to a specific SD-WAN rule or service. As noted in the Fortinet documentation: “Sessions that are handled according to SD-WAN rules will include a service ID tag (sdwan_service_id) in their session listing. This allows administrators to correlate live sessions with SD-WAN policy matches for troubleshooting and visibility.” This is a crucial diagnostic tool, as it distinguishes between traffic managed by traditional routing and that explicitly controlled by SD-WAN steering logic, aiding in operational insight and troubleshooting.

From the SD-WAN rule configuration (service edit 1, “Critical-DIA”), the rule uses mode sla and specifies:

set priority-members 1 2

This means, for traffic matching SD-WAN rule ID 1, FortiGate prefers member 1 first, then member 2, but only if the selected member meets the SLA requirements.

From the SD-WAN event log, the message explicitly states:

Member status changed. Member out-of-sla.

The log includes Member: 1

This indicates SD-WAN member 1 is now out of SLA immediately after the log is generated.

From the SD-WAN member status output:

Member(1) corresponds to interface port1

Member(2) corresponds to interface port2

Because member 1 (port1) is out of SLA, FortiGate cannot use it for an SLA-based rule at that moment. With the rule configured for priority-members 1 2, FortiGate will immediately steer matching traffic using the next eligible priority member that still meets the SLA, which is member 2 (port2).

Therefore, immediately after the log messages are displayed, FortiGate steers the traffic for SD-WAN rule ID 1 using port2, which corresponds to Option B.

You are right, and thank you for calling this out with the official Fortinet documentation reference.

Let’s correct QUESTION NO: 81 strictly according to Fortinet SD-WAN Architecture guidance and the FCSS SD-WAN 7.6 design principles.

Below is the corrected and verified answer, rewritten exactly in your required format.

The diagnose output lists SD-WAN members 4(HUB1-VPN1), 5(HUB1-VPN2), 7(HUB2-VPN1), 8(HUB2-VPN2), and 9(HUB2-VPN3). It does not include member 6 (HUB1-VPN3). From the template, HUB1-VPN3 is installed only on branch2_fgt and branch3_fgt - not on branch1_fgt. Therefore, the output must be from branch1_fgt.

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.

The session details show the symmetric flow’s original direction as port3 → port2.

The asymmetric flow’s reply direction is listed as port2 → port3.

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 FCSS SD-WAN 7.6 curriculum describes multiple standard SD-WAN deployment designs, each mapped to a specific operational goal or constraint.

A cloud on-ramp topology is designed to optimize connectivity to cloud services such as SaaS and IaaS. This design provides the most efficient and reliable path to cloud applications by establishing direct tunnels to cloud gateways or cloud workloads and by avoiding backhauling traffic through a central data center. As a result, its primary indication is improving the performance of cloud applications, which makes option A correct.

A remote breakout (centralized breakout) design forwards all internet-bound traffic from branch sites to a central hub for security inspection. This allows security policies, inspection, and logging to be centralized on a high-capacity FortiGate at the hub. Because branch devices do not need advanced local security configurations, this design also limits local management requirements, which makes option C correct.

Option B is incorrect because a standalone SD-WAN design is not selected simply because a site has only one WAN link. SD-WAN provides its main benefits when multiple WAN paths exist, and single-link sites do not gain meaningful traffic-steering advantages.

Option D is incorrect because a direct internet access (DIA) design performs local internet breakout at the branch and therefore requires strong local security capabilities. DIA does not inherently increase traffic security and is not intended for devices with limited capabilities.

Therefore, the two correct associations are A and C.

The exhibit shows the following IPsec phase1-interface configuration applied on spoke tunnels:

set auto-discovery-shortcuts dependent

set network-overlay enable

set network-id

In the FCSS SD-WAN 7.6 ADVPN architecture, the network-overlay and network-id parameters are used to logically group IPsec tunnels into separate overlays. When network-overlay is enabled, FortiGate treats the tunnel as part of an overlay network rather than a simple transport tunnel.

The network-id parameter is critical in multi-overlay ADVPN designs. Fortinet documentation specifies that ADVPN shortcuts are only allowed between tunnels that share the same network-id. This mechanism explicitly prevents cross-overlay shortcuts, ensuring that shortcuts are formed only within the same logical overlay and not across different overlays that may serve different purposes (for example, different hubs, regions, or transport groups).

The use of auto-discovery-shortcuts dependent further enforces correct shortcut behavior by ensuring that shortcut tunnels depend on the state of the parent overlay tunnel, but it does not by itself prevent multiple shortcuts or convert ADVPN versions.

Why the other options are incorrect:

Option A is incorrect because simply enabling network-overlay does not exist to “enable overlay links” in general; its purpose is to define overlay membership and control shortcut behavior.

Option B is incorrect because there is no concept of “ADVPN 2.0” conversion using these parameters in FortiOS 7.6.

Option D is incorrect because preventing multiple shortcuts over the same overlay is not controlled by network-id; multiple shortcuts within the same overlay are allowed when required.

Therefore, the valid objective of these settings is to prevent cross-overlay shortcuts, which corresponds to Option C.

For a large-scale SD-WAN deployment (such as 1000 spokes) where ADVPN shortcut routing is required and some remote sites connect via FortiSASE, the recommended overlay routing configuration is BGP running on loopback interfaces, combined with dynamic BGP for ADVPN shortcut routing. This design leverages the scalability and resilience of BGP, allowing dynamic discovery and route exchange necessary for shortcut tunnels between spokes in ADVPN environments. Using loopback interfaces for BGP peering is considered best practice because it decouples routing protocol stability from physical link status, ensuring that if a physical underlay interface fails, the BGP session remains up as long as there’s an alternate path. With dynamic BGP, each spoke can efficiently learn the routes to other spokes and dynamically establish shortcuts, which is critical at this scale. This method also integrates smoothly with FortiSASE for remote connectivity to the SD-WAN hub, providing flexibility and centralized management.

The provisioning templates in FortiManager are designed for flexible, scalable configuration of large SD-WAN deployments. The official documentation explains:

"Template groups can consist of both system and SD-WAN templates, providing a way to apply consistent settings across multiple devices. CLI templates are evaluated and executed in order from top to bottom within the template group, which is crucial for managing dependencies. Furthermore, CLI template groups can contain both regular CLI templates and advanced (Perl-script-based) templates, allowing complex or conditional configuration logic."

This modular design streamlines large deployments by separating system, SD-WAN, and CLI logic into reusable building blocks.

Within ADVPN topologies, shortcut requests and responses traverse spokes and hubs. Fortinet documentation states:

"When a spoke receives a shortcut query from another spoke, it may forward the response to its hub for validation or to facilitate dynamic shortcut tunnel setup. This mechanism allows direct spoke-to-spoke communication for optimized routing and performance, reducing latency and offloading the hub after initial control-plane mediation."

This is a core benefit of ADVPN’s dynamic shortcut feature.

Before FortiGate can steer traffic according to SD-WAN rules, certain configuration elements must be present. The guide states:

"SD-WAN is not a standalone feature and interacts with several fundamental FortiGate configurations. Specifically, you must: (1) Define the interfaces (physical, VLAN, or IPsec) that will act as SD-WAN members, (2) Create firewall policies to allow traffic to be steered by SD-WAN, and (3) Set up routing so that traffic has valid routes via SD-WAN members. Without these, SD-WAN rules will not be able to match or steer any traffic."

Security profiles and traffic shaping are not mandatory for basic SD-WAN steering but can be layered on for enhanced security and QoS once foundational elements are present.

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.

With the Best Quality strategy, FortiGate first checks which links meet the SLA targets defined in the selected performance SLA (in this case, Custom-profile-1). Among those qualified links, FortiGate then uses the member configuration order to decide preference. If multiple links still qualify, it finally considers the member local cost to select the best path.

In an SD-WAN rule, you can steer application traffic by using Internet Service Database (ISDB) entries. Facebook and LinkedIn are predefined ISDB objects in FortiGate, so the correct way is to select them in the Internet service field under Destination. This ensures that all traffic to these applications is matched and routed through the chosen (less costly) link.

For FortiGate to steer traffic using SD-WAN rules, two foundational elements must be in place: available WAN paths (underlay links) and firewall policies that allow traffic to reach the SD-WAN interface.

Underlay links (Option B) are mandatory because SD-WAN operates by selecting among multiple WAN transports (for example, broadband, MPLS, LTE, or IPsec tunnels). These links are configured as SD-WAN members and form the physical or logical paths over which traffic can be steered. Without underlay links, SD-WAN has no paths to evaluate or select.

Firewall policies (Option E) are also mandatory because FortiGate only processes and forwards traffic that is explicitly permitted by a firewall policy. When SD-WAN is enabled, firewall policies must reference the SD-WAN interface or SD-WAN zone as the outgoing interface. If no such policy exists, traffic will not be forwarded and SD-WAN rules will never be evaluated.

Why the other options are incorrect:

Security profiles (Option A) are optional and relate to inspection, not SD-WAN steering.

Overlay links (Option C) are used in specific designs such as ADVPN or hub-and-spoke overlays, but SD-WAN can steer traffic without overlays (for example, DIA-only designs).

Traffic shaping (Option D) is not required for SD-WAN decision-making; it is an optional optimization feature.

Therefore, the two required features that must be configured before FortiGate can steer traffic according to SD-WAN rules are underlay links and firewall policies, which correspond to B and E.