Free Practice Questions for Fortinet NSE6_SDW_AD-7.6 Exam

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 < value >

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 .

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.

Application-based SD-WAN rules enable intelligent traffic steering. The guide specifies:

" If a flow is identified as belonging to a defined application category (such as social media), FortiGate will match it to the corresponding service rule (rule 2) and route it through the specified interface, such as port2. However, if the application is not recognized during the session setup, the system defaults to load balancing the traffic using the available tunnels according to the policy for unclassified traffic, ensuring continuous connectivity while waiting for application classification. "

This guarantees both performance and resilience.

The hub must send additional paths to spokes (set additional-path send).

The hub must treat each spoke as a route-reflector client so spoke routes are reflected to other spokes.

The hub must specify how many additional paths to advertise (set adv-additional-path < n > ).

The SD-WAN monitor’s table view in FortiManager provides a donut visualization plus a detailed table that shows each SD-WAN member’s status and SLA pass/miss, giving the per-member health view you’re after.

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 7.6, when a Performance SLA probe mode is set to Prefer Passive , FortiGate attempts to measure link performance using passive monitoring first , based on real user traffic. Only when passive monitoring is not possible does FortiGate temporarily fall back to active probing.

With Prefer Passive , FortiGate passively monitors TCP traffic flowing through the SD-WAN member to calculate SLA metrics such as latency, jitter, and packet loss. This behavior directly matches option A .

During passive monitoring , FortiGate relies on observed traffic to infer link health. Because no synthetic probes are sent, a completely dead link (with no traffic passing) cannot be detected by the SLA during passive mode. As a result, dead members may not be immediately detected, which makes option D correct.

Option B is incorrect because there is no fixed 3-minute timer defined in FortiOS 7.6 that forces a return from active probing back to passive monitoring.

Option C is incorrect because passive SLA monitoring is based on TCP traffic , not ICMP traffic. ICMP is used for active probing , not passive monitoring.

Option E is incorrect because traffic subject to passive SLA monitoring cannot be offloaded to hardware . Passive SLA measurement requires software inspection of packets, which prevents NPU offloading.

Therefore, the two correct observable impacts of configuring the probe mode as Prefer Passive are A and D .

" Another popular MSSP choice is to deploy the hubs on the customer premises, such as at a central office or a data center. The traffic flow in this blueprint is quite different from the two previous scenarios described. The majority of the traffic is likely to be either spoke-to-hub—branch sites accessing workloads hosted in the data center or an RIA through a centralized breakout owned by the customer—or DIA on the spokes. In this type of topology, occasional spoke-to-spoke traffic is possible, but rare, and usually non-existent. "

When referencing a zone in a static route, FortiGate’s behavior is described as:

" Referencing a zone in a static route causes FortiGate to install a static route for each member interface of the zone. This enables ECMP (Equal-Cost Multi-Path) and load balancing where supported and ensures that traffic can be steered over any valid zone member according to SD-WAN rules or standard routing. "

This mechanism is fundamental to Fortinet’s implementation of SD-WAN and simplifies large, multi-interface deployments.