AWS Certified Advanced Networking Specialty Practice Exam

Which of the following is essential for ensuring secure VPC communications?

1. Using default security groups

2. Implementing proper routing policies

3. Configuring Network ACLs and security groups

4. Enabling public accessibility

The correct answer is: Configuring Network ACLs and security groups

Configuring Network ACLs (Access Control Lists) and security groups is crucial for ensuring secure communications within a Virtual Private Cloud (VPC) because these components play a significant role in controlling inbound and outbound traffic to and from resources within the VPC. Network ACLs act as a stateless firewall for controlling traffic moving in and out of subnets, allowing you to specify rules that determine whether to allow or deny traffic based on IP addresses, protocols, and ports. Security groups, on the other hand, serve as stateful firewalls for individual instances, where you can define which protocols and ports are allowed for inbound and outbound traffic specific to that instance. By properly configuring these security mechanisms, you can create a layered security posture to protect resources from unauthorized access and potential threats. This level of granularity helps in monitoring and controlling the flow of packets into and out of your network, allowing for a tailored security approach that fits your VPC architecture. In contrast, relying solely on default security groups is not advisable, as they may not fulfill the specific security requirements for your applications. Implementing proper routing policies is important for directing traffic within and outside of the VPC but does not inherently offer security measures. Enabling public accessibility can expose instances to the