Routing Packets Between VLANs with a Router
When including VLANs in a campus LAN design, the devices in a VLAN need to be in the same subnet. Following the same design logic, devices in different VLANs need to be in different subnets. For example, in Figure 9-7, the two PCs on the left sit in VLAN 10, in subnet 10. The two PCs on the right sit in a different VLAN (20), with a different subnet (20).
The figure refers to subnets somewhat generally, like subnet 10, just so the subnet numbers do not distract. Also, note that the subnet numbers do not have to be the same number as ...