Your administrator instructed you to deploy an Azure vWAN solution to create a connection between...

Comprehensive and Detailed Explanation From FortiOS 7.6, FortiWeb 7.4 Exact Extract study guide:

According to the FortiOS 7.6 Azure Administration Guide and the Fortinet 7.4 Public Cloud Security documentation regarding Azure Virtual WAN (vWAN) architectures, the choice of connectivity depends on the required performance, security, and scale:

ExpressRoute (Option D): For a large-scale enterprise deployment involving a company headquarters and multiple branch sites, ExpressRoute is the "best" and most robust solution. It provides a private, dedicated, and high-throughput connection (up to 100 Gbps) that bypasses the public internet entirely. This ensures predictable low latency and higher reliability compared to internet-based tunnels.

Virtual WAN Integration: Azure vWAN Standard SKU explicitly supports ExpressRoute gateways as a primary connectivity method for on-premises sites. This allows the vWAN hub to act as a global transit point, seamlessly connecting the ExpressRoute-linked headquarters to other branch sites and VNET spokes.

Scalability for Headquarters: While site-to-site IPsec VPNs are common for smaller branches, the "main company site" or headquarters typically requires the high bandwidth and SLA guarantees provided by ExpressRoute.

Why other options are incorrect:

Option A & B: L2TP and SSL VPN are primarily used for remote user access (Point-to-Site) rather than permanent site-to-hub infrastructure connections. vWAN uses OpenVPN or IKEv2 for user VPNs, not L2TP.

Option C: While GRE tunnels are used in some networking scenarios, they are not a native, primary gateway connectivity option for the Azure vWAN hub compared to the standardized Site-to-Site VPN (IPsec) and ExpressRoute.