How AWS Shield mitigates events - AWS WAF, AWS Firewall Manager, and AWS Shield Advanced

How AWS Shield mitigates events

The mitigation logic that protects your application can vary depending on your application architecture. When you protect a web application with Amazon CloudFront and Amazon Route 53, you benefit from mitigations that are specific to web and DNS use cases and that protect all traffic for the services. When your application's entry point is a resource that runs in an AWS Region, the mitigation logic varies depending on the service, the resource type, and your use of AWS Shield Advanced.

AWS DDoS mitigation systems are developed by Shield engineers and they're closely integrated with AWS services. The engineers take into account aspects of your architecture such as the capacity and health of targeted resources. Shield engineers continually monitor the efficacy and performance of DDoS mitigation systems and are able to respond quickly when new threats are discovered or anticipated.

You can architect your application to scale in response to elevated traffic or load, to help ensure that it's not affected by smaller request floods. If you use Shield Advanced to protect your resources, you receive coverage against unexpected increases in your cloud bill that might occur as the result of a DDoS attack.

Infrastructure mitigations

For infrastructure layer attacks, AWS Shield DDoS mitigation systems are present at the AWS network border and at AWS edge locations. The placement of multiple levels of security controls throughout the AWS infrastructure provides defense-in-depth to your cloud applications.

Shield maintains DDoS mitigation systems at all points of ingress from the internet. When Shield detects a DDoS attack, for each point of ingress, it reroutes the traffic through the DDoS mitigation systems in the same location. This doesn’t introduce any observable additional latency, and provides a mitigation capacity of more than 100 TeraBits Per Second (Tbps) across all AWS Regions and all edge locations. Shield protects your resource availability without rerouting traffic to external or remote scrubbing centers, which could increase latency.

  • At the AWS network border, for any AWS service or resource, DDoS mitigation systems mitigate infrastructure layer attacks coming from the internet. The systems perform their mitigations when signaled by Shield detection or by an engineer on the Shield Response Team (SRT).

  • At AWS edge locations, DDoS mitigation systems continuously inspect every packet that's forwarded to Amazon CloudFront distributions and Amazon Route 53 hosted zones, regardless of their origin. When needed, the systems apply mitigations that are specifically designed for web and DNS traffic. An added benefit of using Amazon CloudFront and Amazon Route 53 to protect your web applications is that DDoS attacks are immediately mitigated, without requiring a signal from Shield detection.

Application layer mitigations

Shield Advanced provides web application layer mitigations for the Amazon CloudFront distributions and Application Load Balancers where you've enabled Shield Advanced protections. When you enable protection, you associate an AWS WAF web ACL with the resource, to enable web application layer detection. Additionally, you have the option of enabling automatic applicaton layer mitigation, which instructs Shield Advanced to manage protections for you during a DDoS attack.

Shield only provides mitigations for application layer attacks on resources for which you've enabled Shield Advanced and automatic application layer mitigation. With automatic mitigation, Shield Advanced automatically mitigates attacks with AWS WAF protections, and then removes the mitigations when they're no longer needed. For detailed information about mitigations of this type, see How Shield Advanced manages automatic mitigation.