NSE6_SDW_AD-7.6 Fortinet NSE 6 - SD-WAN 7.6 Enterprise Administrator Questions and Answers

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.

Your requirements map to two key MSSP goals described in the FCSS SD-WAN 7.6 blueprint patterns:

Delegate as much administration and management as possible to the MSSPThis is best achieved when the hub security and SD-WAN control point is located on the MSSP premises, because the MSSP can centrally operate the core enforcement and overlay control. Both option B (dedicated hub at MSSP) and option D (shared hub at MSSP with customer isolation) meet this requirement.

Each site must maintain direct internet access (DIA) and be secure, with significant site-to-site trafficIn Fortinet SD-WAN MSSP designs, spokes can still use local breakout for DIA while also building secure overlays for inter-site traffic. Placing the hub at the MSSP enables centralized security services and scalable inter-site connectivity management while preserving DIA where required. Options B and D support this operating model.

Why the other options do not best match:

A includes a dedicated hub on the customer premises, which reduces how much the MSSP can centralize and operate from its own environment, so it does not maximize delegation.

C places both hub and spokes on the customer premises. While the MSSP can manage using a dedicated ADOM, this blueprint does not align as strongly with “delegate installation and management” to the MSSP as the designs where the hub is hosted and operated from the MSSP premises.

Therefore, the two MSSP deployment blueprints that address your requirements are B and D.

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.

From the SD-WAN rule configuration (service ID 3, name "Corp"), the rule is configured as:

set mode sla

set load-balance enable

set hash-mode source-ip-based

set priority-members 3 4 5

Two SLAs are referenced under config sla

In the diagnose firewall proute list output for service=3 (Corp), FortiGate shows the actual members considered for this rule and their SLA pass status:

oif=19 (HUB1-VPN1) num_pass=2

oif=20 (HUB1-VPN2) num_pass=2

oif=21 (HUB1-VPN3) num_pass=1

Because the rule is SLA-based, FortiGate selects only members that meet the SLA requirements for the rule. The output indicates that HUB1-VPN1 and HUB1-VPN2 pass both SLA checks (num_pass=2), while HUB1-VPN3 passes only one (num_pass=1) and therefore is not selected as an eligible forwarding interface for this rule.

Since load-balance is enabled and the rule uses hash-mode source-ip-based, FortiGate will consistently choose an eligible member based on the source IP hash. For traffic sourced from 10.0.1.101, the session can be steered through either HUB1-VPN1 or HUB1-VPN2 (whichever the hash selects), but not HUB1-VPN3.

Therefore, the correct answer is B.

To allow spokes in different hub-and-spoke groups to establish ADVPN shortcuts, the hubs must be configured to forward and send ADVPN shortcut offers. The key required settings on the hub are auto-discovery-forwarder (for VPNs to hubs) and auto-discovery-sender (for VPNs to spokes). This ensures the hub can facilitate and advertise ADVPN shortcut offers between spokes.

The described design is a multi-region SD-WAN architecture, where:

Each region has its own dual-hub ADVPN domain

Most traffic is intra-region

Inter-region traffic is limited and controlled

Spokes can be single-hub or dual-hub, depending on size and redundancy requirements

According to Fortinet’s SD-WAN Architecture for Enterprise guidance, when deploying multiple ADVPN regions, eBGP is the recommended routing protocol between regions. Each region operates as an independent routing domain (typically iBGP within the region), while eBGP is used to exchange routes between regional hubs. This approach:

Prevents excessive route reflection and scaling issues

Provides clear administrative boundaries between regions

Improves stability and scalability in large global deployments

Matches the exact traffic pattern described (high intra-region, low inter-region traffic)

This is explicitly documented in Fortinet guidance for “Using eBGP between regions with intra-region ADVPN”, which confirms that the architecture described in the question is valid and recommended when eBGP is used between regions.

Why the other options are incorrect:

Option B is incorrect because FortiOS does not impose a hard “four-hub” architectural limit in the described regional model. Each region has its own hubs, not a single flat multihub domain.

Option C is incomplete. While FortiManager Overlay Orchestrator can help operationally, it is not the key architectural requirement that makes this design valid. The question asks what makes the plan correct from a design standpoint, not a tooling standpoint.

Option D is incorrect because FortiOS fully supports mixed spoke connectivity within the same region (some spokes single-hub, others dual-hub), which is a common enterprise SD-WAN design.

Therefore, the correct and documented conclusion is that the plan is possible and eBGP should be used as the routing protocol between regions, which corresponds to Answer A.

When an SD-WAN member is deleted, FortiGate can also remove static routes that were tied to that interface. If those routes are needed for destinations not covered by SD-WAN rules, traffic to those networks becomes unreachable. This explains why flows not matching SD-WAN rules are interrupted after the member was removed.

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 SD-WAN rule (config service edit 1) is configured with set mode priority. This means the rule selects the best interface based on a defined performance metric, as opposed to a simple static priority or SLA. The event log (image_41cfb5.png) shows Metric latency and Message Service prioritized by performance metric will be redirected in sequence order. This indicates that the rule is using latency to determine the preferred member. Given that the log message is about a change, and the most logical reason for a change in a priority mode is that a different member is now the best performer, it implies that the latency on port2 has become lower than that on port1.

The log message Service prioritized by performance metric will be redirected in sequence order confirms that FortiGate is changing the member being used for this service. Because the mode is priority, FortiGate dynamically selects the member that currently meets the best performance criteria, which in this case is latency. The log implies a new member has been selected as the most optimal, and with the default configuration, the members are sorted based on their performance, so the outgoing interface list is effectively updated to prefer the new best-performing member (port2).

The command shown in the exhibit is:

diagnose sys sdwan service 4 3

This command displays the runtime state of SD-WAN rule ID 3 on the device. The output explicitly shows:

Service(3) which confirms the SD-WAN rule being evaluated is rule number 3

Members(9) which indicates that nine SD-WAN members are associated with this rule

The listed members include multiple IPsec tunnel interfaces such as HUB1-VPN1, HUB1-VPN2, HUB1-VPN3, HUB2-VPN1, HUB2-VPN2, and HUB2-VPN3, which is characteristic of a spoke device connecting to multiple hubs in a hub-and-spoke ADVPN topology, as defined in the FCSS SD-WAN 7.6 architecture.

Option B is incorrect because, although members are listed under different interfaces, the output does not indicate SD-WAN zones. Zones are shown only in configuration output, not in this diagnostic command.

Option C is incorrect because this is not a hub device. The presence of multiple hub tunnels as SD-WAN members indicates a spoke role. Additionally, the output does not confirm the number of established ADVPN shortcuts.

Option D is incorrect because the output clearly references SD-WAN rule 3, not rule 4, and it does not state that exactly three shortcut tunnels are allowed.

Therefore, the correct conclusion is that this is a spoke device and SD-WAN rule 3 is configured with nine members, which matches option A.

The SD-WAN overlay template defines a zone for each underlay interface and moves the interfaces into those zones. This statement perfectly describes the likely sequence of events. The template, when applied, re-organizes the interfaces and zones, causing the existing firewall policy that relies on the old zone configuration to fail. This is the most plausible root cause.

In the exhibit, the IPsec tunnel statistics event log entries include the field advpnsc.

Fortinet documents that advpnsc identifies whether the VPN event is based on an ADVPN shortcut:

advpnsc=1 → the tunnel is an ADVPN shortcut

advpnsc=0 → not an ADVPN shortcut (Fortinet Documentation Library)

In the shown logs, the tunnel vpntunnel="HUB1-VPN1_0" has advpnsc=1, which means HUB1-VPN1_0 is an ADVPN shortcut tunnel. (Fortinet Documentation Library)

The other tunnels shown (for example VPN4_0 and HUB2-VPN3) have advpnsc=0, which only indicates no shortcut is identified for those log entries—it does not prove they “cannot accept” shortcuts, only that the specific event is not a shortcut. (Fortinet Documentation Library)

From the SD-WAN monitor in FortiManager:

"The SD-WAN monitor provides a summary view of the branch devices and their members. In the scenario shown, it is clear that branch2_fgt is missing SLA configuration for one member, as evidenced by the lack of performance metrics. The monitor also shows only two branches in the current topology, allowing quick assessment of branch health and configuration completeness."

This kind of visibility is vital for proactive monitoring and rapid troubleshooting in SD-WAN environments.

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.

The rule is in priority mode with HUB1-VPN1 (seq 4) as the first preferred member, HUB1-VPN2 second, and HUB1-VPN3 third. Latency itself does not cause HUB1-VPN3 to become preferred unless a higher-priority member fails SLA. If HUB1-VPN1’s latency exceeds the SLA threshold (here simulated by latency reaching 200 ms), FortiGate stops using it and moves down the priority list. That is when HUB1-VPN3 could become the active path.

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.

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.