What are the best practices for using AWS NACLs?

What are the best practices for using AWS NACLs?

When using AWS Network Access Control Lists (NACLs), consider these best practices: 1. Use NACLs for stateless filtering. 2. Keep rules simple and organized. 3. Apply NACLs at the subnet level. 4. Regularly review and update rules. 5. Monitor traffic logs for anomalies.

Can you explain what stateless filtering means?

Stateless filtering means that each request is evaluated independently, without regard to previous requests. This means that return traffic must be explicitly allowed in the NACL rules.

How do I monitor traffic logs for my NACL?

You can enable VPC Flow Logs in your AWS account to capture information about the IP traffic going to and from network interfaces in your VPC. This will help you analyze the traffic patterns and identify any issues.

Are there any limitations I should be aware of with NACLs?

Yes, NACLs have some limitations, such as a maximum of 20 rules per direction (inbound and outbound) and they do not support stateful filtering, meaning you need to allow return traffic explicitly.