Episode 86: Layer 2 Switches — MAC Tables and Forwarding Decisions

This episode introduces Layer 2 switches, which operate at the Data Link Layer and make forwarding decisions based on MAC addresses. Switches maintain a MAC address table, mapping physical addresses to ports, which allows them to forward frames only to the correct destination rather than broadcasting to all devices. This behavior improves efficiency and reduces unnecessary traffic. Understanding MAC learning and forwarding is a key objective on the exam.

Real-world considerations include how switches learn addresses dynamically, how unknown unicast traffic is handled, and how aging timers clear inactive entries. Troubleshooting scenarios include duplicate MAC addresses, flooded networks caused by unknown destinations, or misconfigured switch ports. By mastering how Layer 2 switches build and use MAC tables, you’ll be able to answer exam questions and diagnose problems in live environments. Produced by BareMetalCyber.com, where you’ll find more cyber audio courses, books, and information to strengthen your certification path.