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 )

In FortiOS 7.6, static routes can reference either:

an SD-WAN zone (for example, virtual-wan-link or a user-defined SD-WAN zone), or

a specific SD-WAN member interface that belongs to that zone.

However, FortiOS enforces a routing constraint to avoid ambiguity during route resolution. Two static routes cannot have the same destination prefix if one points to an SD-WAN zone and the other points to an SD-WAN member within that zone . This would create an overlapping and conflicting forwarding decision.

Therefore, if you configure:

one static route that references an SD-WAN zone, and

another static route that references an SD-WAN member belonging to that same zone,

the destination subnets of the two static routes must be different .

Why the other options are incorrect:

Option A is incorrect because FortiOS does allow static routes that reference individual SD-WAN members.

Option B is incorrect because static routes can reference SD-WAN zones.

Option D is incorrect because static routing decisions in FortiOS are based on destination prefixes, not source prefixes.

Thus, the correct answer is C .

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 .

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.

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 .

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.