Pass the Fortinet Network Security Expert NSE7_CDS_AR-7.6 Questions and answers with Dumpstech

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

In an AWS SD-WAN Transit Gateway (TGW) Connect topology, traffic flow must be meticulously orchestrated through VPC route tables to ensure that the FortiGate-VM (Security VPC) can inspect traffic transitioning between spokes.

Spoke to TGW Redirection (Option E):For traffic to leave a Spoke VPC and reach the inspection hub, theSpoke VPC internal routing tablemust be configured to send all non-local traffic (0.0.0.0/0) to theTransit Gateway (TGW). This is the first step in the traffic chain.

TGW to FortiGate Redirection (Option A):Once the traffic arrives at the TGW and is forwarded to the Security VPC via a TGW attachment, it lands in theTGW subnet(or attachment subnet). To ensure this traffic is inspected, theSecurity VPC TGW subnet routing tablemust point the default route (0.0.0.0/0) to theFortiGate's internal network interface (ENI).

FortiGate Return/Egress Path (Option D):After the FortiGate processes the packet, it must be sent back to the TGW to reach its final destination in a different spoke or to exit via a different gateway. Therefore, theSecurity VPC FortiGate internal subnet routing table(the subnet where the FortiGate's internal leg resides) must have a default route (0.0.0.0/0) pointing back to theTGW.

Why other options are incorrect:

Option B:If the Security VPC TGW subnet routing table points to the TGW as the next hop, it creates a routing loop where traffic arrives from the TGW and is immediately sent back without being inspected by the FortiGate.

Option C:Pointing all traffic to an Internet Gateway (IGW) would bypass the Transit Gateway entirely and send traffic to the public internet rather than through the internal security fabric.

The Fortinet documentation states: "An IGW in AWS is a VPC component that allows communication between instances in your VPC and the internet... AWS users with less experience may face connectivity issues if they create a new VPC, add EC2 instances to it, but forget that they need an IGW for internet connectivity."

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

According to theFortiOS 7.6 Azure Administration Guideand theFortinet 7.4 Public Cloud Securitydocumentation 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 acompany headquartersand multiplebranch sites, ExpressRoute is the "best" and most robust solution. It provides aprivate, 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 supportsExpressRoute gatewaysas 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 byExpressRoute.

Why other options are incorrect:

Option A & B:L2TPandSSL VPNare 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:WhileGRE tunnelsare 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.

According to theFortiOS 7.6 Azure Administration Guideand theCloud Security 7.4 Public Cloud Study Guide, the integration of FortiGate-VMs with an Azure Gateway Load Balancer (GWLB) requires specific network configurations to ensure packet transit:

IP Forwarding Requirement (Option A):By default, Azure Network Interfaces (NICs) drop any traffic that does not originate from or is not destined for the IP address assigned to that NIC. For a FortiGate to act as a "bump-in-the-wire" or transparent inspector, it must receive traffic destined for other IPs and forward it. This requires theIP Forwardingsetting to be explicitlyenabledon the FortiGate's network interfaces within the Azure portal. If this is disabled, the Azure fabric will discard the traffic being steered through the FortiGate HA cluster by the GWLB.

VXLAN Encapsulation:The Azure GWLB uses VXLAN to encapsulate traffic (adding a VXLAN header with a specific VNI) before sending it to the FortiGate. The FortiGate must terminate this VXLAN tunnel. While the VXLAN configuration is crucial, the underlying infrastructure check for IP Forwarding is the most common cause of traffic being blocked at the NIC level before the FortiOS stack can process the packet.

Why other options are incorrect:

Option B:If health probes fail, the GWLB will typically stop sending traffic to that specific instance. While this affects the HA cluster's availability, the question states traffic is not being routedcorrectlythrough the firewalls (implying an active flow issue), and the primary mechanism for allowing a VM to process third-party traffic in Azure is IP Forwarding.

Option C:NSGs are typically applied to the NIC or Subnet. While incorrect NSG rules can block traffic, "IP Forwarding" is a specific requirement for the FortiGate to function as a network appliance (NVA) regardless of the NSG state.

Option D:Azure GWLB supportscross-subscriptionand cross-tenant chaining. The consumer (protected VMs) and the provider (FortiGate HA cluster) do not need to be in the same subscription, provided the GWLB endpoint is correctly mapped.