Firewalls and access control lists are the gatekeepers of your network, and understanding how to configure them correctly is essential. This episode explains how to structure firewall rules and ACLs (Access Control Lists) using principles like implicit deny, least privilege, and rule order. You'll learn how rules are evaluated top-down and why a misplaced permit or deny can either expose sensitive systems or unintentionally block legitimate traffic.

We cover standard vs. extended ACLs, how to apply them to inbound vs. outbound traffic, and best practices like logging, naming, and change documentation. Troubleshooting ACL behavior is also discussed, with a focus on rule testing and log interpretation. This episode equips you with the skills to both lock down traffic and troubleshoot configuration issues with confidence.