Exam AWS Certified Solutions Architect - Associate SAA-C03 topic 1 question 208 discussion

I think answer should be A and not B. as we cannot "Attach a security groups to a gateway endpoint."

The correct solution to meet the requirements is Option B. A gateway VPC endpoint for Amazon S3 should be created in the Availability Zone where the EC2 instance is located. This will allow the EC2 instance to access the S3 bucket directly, without routing through the public internet. The endpoint should also be configured with appropriate security groups to allow access to the S3 bucket. Additionally, a resource policy should be attached to the S3 bucket to only allow the EC2 instance's IAM role for access.

Here's why this option is suitable: Gateway VPC Endpoint for Amazon S3: A gateway VPC endpoint allows you to privately connect your VPC to supported AWS services, such as Amazon S3, without requiring an internet gateway, NAT device, VPN connection, or AWS Direct Connect connection. Traffic between your VPC and the service does not leave the Amazon network. Resource Policy: By attaching a resource policy to the S3 bucket that only allows access from the EC2 instance's IAM role, you ensure that only authorized instances can access the bucket. Here's why the other options are not as suitable: A. Create an interface VPC endpoint for Amazon S3: Amazon S3 uses gateway VPC endpoints, not interface VPC endpoints. Interface VPC endpoints are used for services that are not supported by gateway endpoints.

Interface Endpoint = AWS PrivateLink Gateway Endpoint = Supports S3 and DynamoDB

Reasons for B: Simplicity: Gateway VPC endpoints are easier to configure and manage compared to interface VPC endpoints. Cost: Gateway VPC endpoints are free to use, whereas interface VPC endpoints incur costs for each hour and per GB of data processed. Performance: Gateway VPC endpoints are highly scalable and optimized for S3 and DynamoDB traffic.

gateway endpoint does not have any SG.

A VPC gateway endpoint is primarily used for accessing specific AWS services like Amazon S3 and DynamoDB privately within your VPC by specifying a route in your route table, while a VPC interface endpoint offers more flexible connectivity to a wider range of AWS services through AWS PrivateLink, allowing access from both within your VPC and from other VPCs using peering or Transit Gateways, typically with a dedicated private IP address within your VPC network; essentially, gateway endpoints are simpler and often free, while interface endpoints provide greater control and may incur additional costs depending on usage. Gateway endpoints are ideal for simple private access to S3 and DynamoDB, while interface endpoints are better suited for more complex scenarios where you need to access various AWS services from different VPCs or on-premises networks.

Even though Amazon S3 typically uses a Gateway VPC Endpoint, AWS now provides Interface VPC Endpoints for Amazon S3 as well via AWS PrivateLink....and "Attach a security groups to a gateway endpoint." makes the option B - false

B will be correct if removing the "Attach appropriate security group to the endpoint" and gateway point is free of charge.

Option A uses an interface VPC endpoint, which is typically used for services that require a private IP address within your VPC. For S3, a gateway VPC endpoint is more appropriate and cost-effective1

Interface VPC Endpoint: Interface endpoints are generally used for other AWS services and do not provide the same direct access optimization for S3 that gateway endpoints do.

In this context, a Gateway VPC Endpoint is the correct choice for S3, as it provides direct, private access to S3 and routes traffic internally within the AWS networ

Why Option B is Correct: Gateway VPC Endpoint for Amazon S3: S3 does not require an interface endpoint; it uses a gateway VPC endpoint. Gateway endpoints ensure that requests stay within the AWS network, meeting the requirement of no public internet routes. Resource Policy: Attaching a bucket policy ensures that only the EC2 instance's IAM role has access to the bucket. Appropriate Security Controls: The gateway endpoint can be secured further using policies and security group configurations.

It is A. Gateway endpoint route table. Interface endpoint uses security groups and private link. See aws video https://youtu.be/TqApkvJx5hw?si=9Gpk3V7OcPU6MVJI

gateway VPC endpoint is used for connect from VPC to S3 and DynamoDB

You might initially lean toward Option B since a gateway endpoint is generally the preferred solution for EC2 instances in the same region. It’s cost-effective (free), performance-optimized, and simpler to configure. However, for the exam, technical precision in details is crucial. Option B is incorrect because: Gateway VPC endpoints are created at the VPC level, not at the Availability Zone level. Security groups must be attached to the EC2 instance (the source service) to allow outbound traffic using the prefix list associated with the gateway endpoint. Due to these reasons, Option A is the correct answer. While not ideal in real-world scenarios for EC2 instances in the same region, it is technically accurate and satisfies the exam's requirements.

correct ans is B