Amazon Web Services SAA-C03 Exam With Confidence Using Practice Dumps

To ensure ALB access only via CloudFront, AWS prescribes restricting the origin to traffic from CloudFront. For ALB origins, the standard pattern is to allow inbound to the ALB only from CloudFront edge IP ranges using security groups or ALB listener rules. Network ACLs are coarse and stateless and add operational burden. CloudFront does not have a “VPC origin” object; instead, CloudFront references the ALB DNS name. By limiting the ALB’s security group to CloudFront IP ranges, direct client access to the ALB is blocked while CloudFront remains permitted. This aligns with security best practices to “restrict origin access to only CloudFront” and use SGs for instance/ALB layer controls.

The most effective way to reduce load on the web servers is to move the static video content toAmazon S3and deliver it throughAmazon CloudFront. CloudFront caches content at edge locations so repeated requests are served closer to users without repeatedly hitting the origin. AWS documentation also recommendsorigin access control OACto securely restrict direct access to the S3 origin and allow CloudFront to fetch the objects on behalf of viewers. ElastiCache is not a video-origin service, EFS would still keep the web servers in the delivery path, and File Gateway is for hybrid file access rather than internet content distribution. For high-traffic video delivery with the least origin load, S3 plus CloudFront with OAC is the correct design.

Using S3 gateway endpoints allows private and cost-free access to S3 without routing traffic through a NAT gateway. NAT gateway traffic incurs charges, especially when used across multiple Availability Zones.

By using an S3 gateway endpoint, EC2 instances in private subnets can access S3 directly without needing internet access, reducing both data transfer and NAT gateway costs.

Interface endpoints are more expensive and typically used for services like API Gateway or Systems Manager.