Two Virtual LANs: Broadcasts Do Not Leave the Originating VLAN

The network engineer configured ports E0 and E1 to be in VLAN 1 and ports E2 and E3 to be in VLAN 2. The switch considers the two VLANs to be separate. In fact, this network behaves just like it would with the two physical switches shown in Figure 7-4. However, you get the advantage of not having to buy another switch!

Notice that the switch keeps a separate address table for each VLAN. So, the switch does learn all four MAC addresses, but the switch does not forward broadcasts or unicasts from one VLAN to the other. Figure 7-6 outlines the process.