SAA-C03 Exam Dumps : AWS Certified Solutions Architect - Associate (SAA-C03)

The optimal solution for scalable and resilient hybrid networking is to use AWS Direct Connect with a Direct Connect gateway for secure, low-latency access to AWS, and an AWS Transit Gateway to manage connectivity among hundreds of VPCs.

By associating the Transit Gateway with the Direct Connect gateway, you enable transitive routing between on-premises and all VPCs, while minimizing network complexity and maintaining high performance.

VPC peering does not scale well, and VPNs don’t offer the same performance or consistency.

Correct Approach:

AWS Security Groups:

Security groups operate at the instance level, making them the ideal tool for controlling access to specific resources such as an Amazon RDS database.

By default, security groups deny all incoming traffic. You can allow access by explicitly specifying another security group.

Associating an RDS database security group with the EC2 instances ' security group ensures only the specified EC2 instances can access the RDS database.

Incorrect Options Analysis:

Option A: Using CIDR blocks for IP-based access is less secure and more difficult to manage. Additionally, Auto Scaling groups dynamically allocate IP addresses, making this approach impractical.

Option B: Network ACLs (NACLs) operate at the subnet level and are stateless. While NACLs can deny or allow traffic, they are not suited to application-specific access control.

Option D: Similar to Option B, using a NACL with CIDR ranges for EC2 IPs is difficult to manage and not application-specific.

DynamoDB on-demand capacity mode is the best fit when traffic is unpredictable and the application must automatically scale read and write throughput without capacity planning. In on-demand mode, DynamoDB instantly accommodates changing request rates and charges based on actual read and write requests, which avoids over-provisioning for unknown traffic patterns. The DynamoDB Standard table class is appropriate because the workload expects moderate to high read and write activity. DynamoDB Standard-IA is designed for tables where storage is dominant and access is infrequent, so it is not the best match for an actively used web application backend. Provisioned capacity with auto scaling can be cost-effective for predictable workloads, but unpredictable traffic makes on-demand mode the safer and more operationally efficient choice.