Painting the Road Signs:Learning MAC Addresses

Painting the Road Signs: Learning MAC Addresses

Switches forward frames based on the destination MAC address in the frame. But how does the switch figure out what should be in the MAC address table in the first place? Well, as it turns out, switches dynamically learn MAC addresses and the corresponding ports. This process of learning MAC addresses, according to switch experts, is cleverly called learning.

Figure 6-9 shows the familiar old network with Fred and the gang. However, at Step 1, the switch has no entries in the MAC address table. This is typical when the switch first powers up.