Firewalls are the gatekeepers of the network, filtering traffic based on defined rules to enforce security policy. In this episode, we explore the various types of firewalls, including packet-filtering, stateful, and next-generation firewalls. You’ll learn how stateful inspection tracks the state of active sessions, allowing for dynamic rule evaluation instead of static filtering. This approach improves security by only allowing return traffic that matches an existing session.

We also dive into how access control lists (ACLs) are implemented, how firewalls handle NAT, and how rule order and default-deny policies can lead to unexpected behavior. You'll leave this episode with a clear understanding of how firewalls protect against unauthorized access while still allowing legitimate traffic to flow. Whether configuring home firewalls or enterprise-level appliances, mastering these principles is essential for effective traffic control and exam success.