AWS WAF, AWS Firewall Manager, and AWS Shield Advanced
Developer Guide (API Version 2015-08-24)

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Responding to DDoS Attacks

AWS automatically addresses layer 3 and layer 4 DDoS attacks. If you use Shield Advanced to protect your Amazon EC2 instances, during an attack Shield Advanced automatically deploys your Amazon VPC network ACLs to the border of the AWS network, which allows Shield Advanced to provide protection against larger DDoS events. For more information about network ACLs, see Network ACLs.

If DDoS alarms in CloudWatch indicate a possible layer 7 attack, you have two options:

  • Investigate and mitigate the attack on your own. If you determine that the activity represents a DDoS attack, you can create your own AWS WAF rules to mitigate the attack. AWS WAF is included with AWS Shield Advanced at no additional cost. AWS provides preconfigured templates to get you started quickly. The templates include a set of AWS WAF rules, which are designed to block common web-based attacks. You can customize the rules to fit your business needs. For more information, see AWS WAF Security Automations and Creating a Web ACL.

    If you use AWS Firewall Manager, you can add these rules to a Firewall Manager-AWS WAF policy.

  • If you are an AWS Shield Advanced customer, you also have the option of contacting the AWS Support Center to get help with mitigations. Critical and urgent cases are routed directly to DDoS experts. With AWS Shield Advanced, complex cases can be escalated to the DRT, which has deep experience in protecting AWS, Amazon.com, and its subsidiaries.

    To get DRT support, contact the AWS Support Center. Select the following options:

    • Case type: Technical Support

    • Service: Distributed Denial of Service (DDoS)

    • Category: Inbound to AWS

    • Severity: Choose an appropriate option

    When discussing with our representative, explain that you are an AWS Shield Advanced customer experiencing a possible DDoS attack. Our representative will direct your call to the appropriate DDoS experts. If you open a case with the AWS Support Center using the Distributed Denial of Service (DDoS) service type, you can speak directly with a DDoS expert by chat or telephone. DDoS support engineers can help you identify attacks, recommend improvements to your AWS architecture, and provide guidance in the use of AWS services for DDoS attack mitigation.

    Important

    For layer 7 attacks, the DRT can help you analyze the suspicious activity, and then assist you to mitigate the issue. This mitigation often requires the DRT to create or update AWS WAF web access control lists (web ACLs) in your account. However, they need your permission to do so. We recommend that as part of enabling AWS Shield Advanced, you follow the steps in Step 4: (Optional) Authorize the DDoS Response Team to proactively provide the DRT with the needed permissions. Providing permission ahead of time helps to prevent any delays in the event of an actual attack.

    You can also contact the DRT before or during a possible attack to develop and deploy custom mitigations. For example, if you are running a web application and need only ports 80 and 443 open, you can work with the DRT to preconfigure a web ACL to "allow" only ports 80 and 443.

    You authorize and contact the DRT at the account level. That is, if you use Shield Advanced within a Firewall Manager-Shield Advanced policy, the account owner, not the Firewall Manager administrator, must contact the DRT for support. The Firewall Manager administrator can contact the DRT only for accounts that they own.