Securing inbound traffic flows into AWS (for example, AWS WAF, AWS Shield, Network Firewall)

What is AWS WAF and how does it help in securing inbound traffic flows?

AWS WAF is a web application firewall that helps protect web applications or APIs against common web exploits and bots that may affect availability, compromise security, or consume excessive resources. It offers customizable web security rules that allow you to block, allow, or monitor (count) web requests based on conditions such as IP addresses, HTTP headers, HTTP body, URI strings, and more.

Can you explain how AWS Shield protects AWS resources, and what is the difference between AWS Shield Standard and AWS Shield Advanced?

AWS Shield is a managed Distributed Denial of Service (DDoS) protection service. AWS Shield Standard offers basic protection for all AWS customers at no additional cost and is designed to protect against most common, frequently occurring network and transport layer DDoS attacks. AWS Shield Advanced provides additional protection against larger and more sophisticated attacks, and it offers features like enhanced DDoS protection, 24×7 access to the AWS DDoS Response Team (DRT), and financial protection against DDoS-related spikes in your AWS bill.

Describe how you would go about implementing a Network Firewall in an AWS environment.

To implement an AWS Network Firewall, first create a firewall policy that outlines the stateful and stateless rule groups for traffic inspection. Then define the firewall by associating the policy with a VPC and selecting the subnets where the firewall endpoints will be placed. Finally, configure route tables to direct the desired traffic through the firewall endpoints. AWS Network Firewall automatically scales with traffic flows, providing high availability and easy management within an AWS environment.

What are the core components of AWS WAF, and how do they interact to provide protection?

Core components of AWS WAF include web ACLs (Access Control Lists), rules, and rule groups. A web ACL acts as a container for rules and rule groups, which contain conditions used to target specific traffic. Rules can be either custom-defined by the user or managed by AWS or AWS Marketplace sellers. When a request is received, AWS WAF evaluates it against the rules in order, allowing or blocking requests based on the conditions set in each rule.

How does AWS Network Firewall differ from security groups and network access control lists (NACLs)?

AWS Network Firewall is a stateful, managed, firewall service for Virtual Private Cloud (VPC) that provides fine-grained control over network traffic. Unlike security groups, which are stateful and operate at the instance level, or NACLs which are stateless and operate at the subnet level, AWS Network Firewall allows you to specify comprehensive, stateful firewall rules across all traffic flowing in and out of a VPC.

What is the purpose of managed rule groups in AWS WAF, and how can they benefit an organization?

Managed rule groups in AWS WAF are a set of pre-configured rules maintained by AWS, AWS Marketplace sellers, or AWS Partner Network (APN) partners. They provide ready-made protection against common threats like SQL injection, XSS, or known bad IPs. These rule groups are updated to react to new threats as they emerge, providing a resource-efficient way for organizations to maintain robust security without the need for in-depth web traffic expertise.

How can you integrate AWS WAF with Amazon CloudFront, and what are the benefits of this integration?

AWS WAF can be directly integrated with Amazon CloudFront by associating a web ACL with a CloudFront distribution. The benefit of this integration is that it puts security protection at the edge of AWS’s network, providing low latency and improved performance. Moreover, it helps in defending against attacks before they reach the web application or origin servers, reducing the potential for damage and resource consumption.

How do you configure AWS Shield to protect against DDoS attacks?

AWS Shield Standard is automatically enabled for all AWS customers, so no configuration is needed to get basic protection. However, for advanced protection with AWS Shield Advanced, you can subscribe to the service and select the resources you want to protect, such as Elastic IP addresses, CloudFront distributions, and Route 53 hosted zones. You can then define DDoS protection plans, engage the DDoS Response Team, and optionally configure alarms and metrics through Amazon CloudWatch for real-time monitoring.

What metrics should you monitor to identify potential security threats or DDoS attacks within an AWS environment?

Metrics to monitor include network traffic anomalies, such as spikes in incoming requests, request rates from individual IP addresses, HTTP error codes indicating rejection of requests, or a high number of dropped packets. Additionally, for AWS deployments, keeping an eye on CloudWatch metrics such as `IncomingRequestCount` or `RequestCountPerTarget`, and utilizing AWS-specific metrics like `DDoSDetected` and `DDoSAttackVolume` can help identify potential DDoS attacks early on.

In what scenarios would you choose AWS Network Firewall over AWS WAF or vice versa?

AWS WAF is more suited for application layer protection (OSI Layer 7) and is used to inspect HTTP/HTTPS traffic for web applications, whereas AWS Network Firewall is a stateful firewall service for OSI Layers 3 (Network) and 4 (Transport), allowing for broader traffic inspection capabilities, including non-HTTP protocols. You would choose AWS Network Firewall when you need to protect against threats across a wide range of network protocols and port options, whereas AWS WAF would be the choice for fine-tuned web application protection.