MAC Learning & Forwarding
Switching
Overview
A learning bridge records source MAC, ingress port and VLAN. Known unicast forwards to the learned destination port. Unknown unicast floods eligible ports in the same VLAN except ingress. A move updates the source location; aging removes stale entries. This exercise describes a learning table separate from the topology engine.
Protocol stages
- 1Receive frame
- 2Learn source MAC
- 3Lookup destination
- 4Unicast or flood
Interactive exercise
Knowledge check
The source MAC is new and the destination MAC is unknown in VLAN 10. What does the switch do?
Educational model — not real hardware, traffic or official certification.