Amazon Web Services Updated SOA-C03 Exam Questions and Answers by saint

According to AWS Cloud Operations and VPC Networking documentation, when VPCs are peered, security groups can reference peer account security groups directly to restrict traffic between them.

This feature allows specifying the security group ID (sg-1234abcd) from the source account (111122223333) in the target database’s security group inbound rule. AWS automatically validates that the VPCs are connected through an existing VPC peering connection and that mutual permissions are properly configured.

You do not prefix the security group ID with the account or peering connection (Options A and B), and using the destination account ID (Option D) is incorrect because it represents the database side, not the source.

Hence, the correct configuration is Option C, which references the application servers’ security group directly for precise, least-privilege access control.

When mapping one domain name to another domain name that is hosted outside AWS, a CNAME record is the correct DNS record type. CNAME records map an alias name (www.company.com ) to a canonical domain name (app.example.com).

Alias records cannot be used to point to non-AWS resources. A and PTR records map IP addresses, not domain names, and are therefore not appropriate.

Because www.company.com is not the zone apex, a CNAME record is valid and supported. This solution requires no additional infrastructure and is the standard DNS approach for this scenario.

Comprehensive and Detailed Explanation From Exact Extract of AWS CloudOps Documents:

For users in eu-west-2 transferring large files to/from an S3 bucket in ap-southeast-2 over the public internet, S3 Transfer Acceleration is designed to improve performance by leveraging the AWS global edge network. With Transfer Acceleration enabled, users access the bucket via the acceleration endpoint. Requests enter AWS at the nearest edge location and then traverse the AWS backbone network to the bucket’s Region, which typically reduces latency variability and can improve throughput for long-distance transfers.

Option A is incorrect because access points do not “replicate destinations” in the way described, and an access point in another Region does not move data closer by itself. Option B is incorrect because Route 53 DNS routing does not accelerate data transfers; it only resolves names and (in this case) also incorrectly references S3 website endpoints (not appropriate for general large file transfer APIs). Option C is not valid as written because a single S3 access point cannot be “associated with both buckets,” and maintaining two buckets introduces synchronization/consistency overhead; it’s not the least-friction acceleration approach for direct internet users.

Comprehensive and Detailed Explanation From Exact Extract of AWS CloudOps Documents:

The requirement is classic active-passive (production in us-east-1, DR in us-west-2 “only for failover”). The most operationally efficient and purpose-built solution is Route 53 failover routing combined with health checks. With failover routing, Route 53 designates one record as PRIMARY (us-east-1) and another as SECONDARY (us-west-2). Route 53 continuously evaluates the health check associated with the primary endpoint (commonly the ALB DNS name or a specific health-check path). If the primary fails, Route 53 automatically returns the secondary record, directing client DNS resolution to the DR region. This ensures us-west-2 is used only when us-east-1 is unhealthy, directly matching the requirement.

Latency routing (Option B) is designed to route users to the region with the lowest latency, which can actively send traffic to us-west-2 even when us-east-1 is healthy—violating the “DR only” constraint. Options C and D introduce custom automation (CloudWatch + Lambda + DNS record updates) that increases operational overhead, adds failure modes, and is unnecessary because Route 53 already provides managed health-check-based failover. Additionally, “EC2 instance terminated” is not a reliable proxy for full application availability, and DNS modification automation is more complex than using native Route 53 failover policies.