Networking Fundamentals

Layer 3 switches and VLANs

Besides classifying switches as managed or unmanaged, we can also classify them as being a layer 2 or a layer 3 switch. A layer 2 switch only supports the use of forwarding data based on MAC addresses, whereas a layer 3 switch also offers additional support in terms of being able to recognize the IP address of an interface, and also provides traffic routing using an IP address. This is essential when routing traffic between VLANs. In Chapter 2, Understanding Local Area Networks, we learned how VLANs segment a network into subnets and that no direct communication can take place between them. For them to be able to communicate with each other, you need to implement a router or a layer 3 switch.

When creating a VLAN, ...