FCSS_SDW_AR-7.6 VCE Exam Download

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 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.

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)