Traffic Direction through GWLB Endpoint:
The ingress route table directs inbound traffic to the GWLB through a GWLB endpoint (GWLBe). This endpoint is responsible for directing traffic to the Gateway Load Balancer for further processing (Option B).
GENEVE Encapsulation:
The GWLB encapsulates the inbound traffic using the GENEVE protocol. This encapsulated traffic is then sent to FortiGate instances for security inspection. The use of GENEVE ensures that the original traffic context is preserved and can be analyzed by FortiGate (Option D).
Other Options Analysis:
Option A is incorrect because GWLB does not forward traffic without encapsulation in its dedicated subnet.
Option C is incorrect as the inbound traffic is directed to the GWLB endpoint first, not directly to the application subnet.
Reference:
AWS Gateway Load Balancer Documentation: AWS GWLB
GENEVE Protocol Overview: GENEVE Protocol