This podcast is made by Ran Chen, who holds an EA license, Insurance and Securities licenses (Series 6, 63, 65), and the CFP® designation. He is passionate about opening access to high-quality exam preparation resources and helping learners prepare more effectively for professional certification exams.

In this episode you will learn:

- Security Groups are stateful firewalls at the instance level, while NACLs are stateless firewalls at the subnet level.

- "Stateful" means return traffic is automatically allowed, whereas "stateless" requires explicit outbound rules for return traffic.

- A public subnet is defined by having a route table entry that points to an Internet Gateway (IGW).

- To explicitly block a specific IP address, you must use a NACL, as Security Groups only support "allow" rules.

- Troubleshooting network connectivity requires checking both the instance's Security Group and the subnet's NACL.

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