AWS Network Firewall vs. Security Groups vs. NACLs


Course Introduction
How IAM is used to securely manage access
IAM Features
PREVIEW10m 39s
Managing user identities with long term credentials in IAM
Creating IAM Users
Using IAM policies to define and manage permissions
Cross-account access
Key Management Service (KMS)
What is KMS?
Components of KMS
AWS Web Application Firewall
AWS Firewall Manager
12m 16s
AWS Shield
AWS Secrets Manager

The course is part of this learning path

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5h 31m

This section of the AWS Certified Solutions Architect - Professional learning path introduces the key identity management, security, and encryption services within AWS relevant to the AWS Certified Solutions Architect - Professional exam. Core to security is AWS Identity & Access Management commonly referred to as IAM. This service manages identities and their permissions that can access your AWS resources, so understanding how this service works and what you can do with it will help you to maintain a secure AWS environment. IAM is an important service in ensuring your resources are secure.

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Learning Objectives

  • Learn about identity and access management on AWS, including users, groups & roles, IAM policies, MFA, identity federation, and cross-account access
  • Learn the fundamentals of AWS Web Application Firewall (WAF), including what it is, when to use it, how it works, and why use it
  • Understand how to configure and monitor AWS WAF
  • Learn about AWS Firewall Manager and its components
  • Learn how to configure AWS Shield
  • Learn the fundamentals of AWS Cognito

In this lecture, we need to discuss the difference between an AWS Network Firewall, Security groups, and our Network access control list. An AWS security group is a virtual firewall used to protect AWS instances. Now, we can't just say EC2 instances because security groups are used for AWS services that deploy AWS-managed instances to support AWS-managed services. Wow, a lot of managed in that sentence. Example, AWS directory services uses EC2 instances to support the service, but you can't access the instances since it's a managed service. 

SGs, or Security groups, have granular rules for inbound/outbound traffic. By default, all outbound traffic is allowed out, but you can explicitly deny certain types of outbound traffic. Security groups are considered stateful. So, traffic that is allowed outbound will be allowed back inbound since the communication has already been established. If you want to allow other types of inbound traffic where the communication did originate from the instance, then an inbound rule will need to be configured. 

What about Network access control lists, or what's typically referred to as NACLs? NACLs do not protect instances. They only protect the network around the infrastructure. Example, you can govern the access and network traffic to public and private subnets within a VPC utilizing a different set of rules. The default is to allow all traffic to go through because, let's face it, Network access control lists are tough to work with and understand if you aren't used to it. Now, how does AWS Network Firewall fit into the picture with Security groups and Network access control list?

We can easily take security groups out of this comparison because they only protect instances. The real comparison is AWS Network Firewall versus NACLs. If you're looking to fully manage all of your VPc network traffic, set up alerting, logging, handle application traffic, integration with AWS WAF and AWS Shield using AWS Firewall Manager, my suggestion would be to go with AWS network firewalls. If not, it's probably easier to use NACLs and what I'd like to call a 'set it and forget' method that provides you with VPC security.


About the Author
Learning Paths

Danny has over 20 years of IT experience as a software developer, cloud engineer, and technical trainer. After attending a conference on cloud computing in 2009, he knew he wanted to build his career around what was still a very new, emerging technology at the time — and share this transformational knowledge with others. He has spoken to IT professional audiences at local, regional, and national user groups and conferences. He has delivered in-person classroom and virtual training, interactive webinars, and authored video training courses covering many different technologies, including Amazon Web Services. He currently has six active AWS certifications, including certifications at the Professional and Specialty level.