Switches rely on MAC address tables to decide where to forward frames, and this episode walks you through exactly how these tables are built and maintained. You'll learn how switches learn the source MAC address of each incoming frame and associate it with the port that received it. This learning process allows switches to make intelligent forwarding decisions, sending frames only to the appropriate destination port rather than flooding the network.

We also cover how MAC address tables age out entries over time, how this behavior impacts performance and security, and how static MAC entries can be manually configured for high-security environments. The episode explains how to view and interpret MAC tables using CLI commands and explores common troubleshooting scenarios, such as table overflow or MAC flapping. Mastering MAC address tables is key to understanding how Layer 2 switching works at a fundamental level.