You configure the overlay tunnels for an SD-WAN hub-and-spoke topology defined with IPsec tunnels, BGP...

The SD-WAN 7.6 Enterprise Administrator Study Guide identifies the recommended BGP-on-loopback IPsec settings. For branches, it specifies:

“Static tunnel type (remote end IP address is known).”

“net-device enable.”

Enabling net-device on the spoke creates a kernel interface for the tunnel. This assists with tunnel monitoring and management and is required to support ADVPN shortcut tunnels. Dynamic BGP establishes on-demand BGP peerings between spokes after an ADVPN shortcut is created; therefore, the spoke must support those dynamic shortcut interfaces. This makes option C correct.

The spoke should also configure localid. The FortiOS 7.6 Administrator Study Guide explains: “Local ID: if the peer accepts a specific peer ID, type that same peer ID in this field.” The local ID supplies the spoke’s IKE identity to the dial-up hub, allowing the hub to identify and authenticate the connecting spoke correctly. Therefore, option D is correct.

Option A reverses the recommended roles. The hub must use a dynamic tunnel type because it operates as the dial-up server and does not require every spoke’s changing public gateway address in advance.

Option B is also incorrect. The guide states: “There is no need to configure any tunnel IP address, so the IKE Mode Config is not used.” BGP on loopback uses the loopback address and exchange-interface-ip instead of IKE mode configuration.