Name: Layer 2 vs Layer 3 Switches
Uploaded: 2025-11-15T00:36:41.000Z
Duration: 6 min 2 s
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In this video, we're going to be talking about the difference between layer two and layer three switches.

So the first thing we have to determine is, well, what is a switch?

Now, a switch is a device that has multiple ports that accepts Ethernet connections from network devices.

And its function is to create a network by allowing devices to talk to each other and exchange data.

Now, the term layer refers to the different layers in the OSI model.

OSI stands for Open Systems Interconnection.

And this model was created as a standard that describes how information from software in one device moves through a network to reach software in another device.

And it does this by breaking down the huge task of data communication into seven different layers, giving control of a data being sent from one layer to another.

So a layer two switch, just like its name says, operates at layer two of the OSI model, which is the datalink layer.

a layer two switch uses the Mac address of a device to determine where to send data.

So when devices connect to a layer two switch, the switch will learn the Mac addresses of those devices and store them in its table.

So when a data packet is sent from a device connected to a layer two switch, the switch will forward the data to the intended destination port.

So, as an example, if computer A wanted to talk to computer B, computer A will put computer B's Mac address in the data packet and then send it to the switch.

And then the switch will read the destination's Mac address and then look at its table to determine which port matches the specified Mac address.

And then it'll forward the data to that port where computer B is connected.

Layer 2 switches are by far the most common type of switches.

These are the traditional switches that you'll find in homes and small to medium sized businesses.

Now, a layer three switch, which is also called a multi layer switch, operates at layer three of the OSI model.

Layer three is the network layer, and this has to do with routing, which deals with IP addresses.

So a layer three switch can route data using IP addresses.

But in addition to operating at layer three, it can also operate at layer two.

So it can forward data by using Mac addresses which are layer two, and

it can also route data using IP addresses which are layer three.

So as an example, let's say that in a business, they wanted to separate the network traffic from a couple of different apartments so that the support department doesn't see any traffic from sales and vice versa.

And the best and easiest way to do this is by creating a couple of VLANs VLANs divide a network into separate broadcast domains.

So for the support department, we'll create a VLAN, and

then we'll give it this IP address group, and then we'll call it VLAN 10.

And then we'll configure a VLAN for the sales department with a different IP address group, and

So now, because of the VLANs, each department is on their own subnet, and

the devices in each VLAN can't see or communicate with devices in the other vlan.

But what if, for some reason, the network administrator wanted to allow communication to happen between the two VLANs, but

because the VLANs have different IP address groups, in order for communication to happen, this requires a layer three device.

Now, it could use a router to do this, because routers route by IP addresses.

But a better and easier way to do this is by using a layer 3 switch.

By using and configuring a layer 3 switch, it'll allow communication between the VLANs, which is known as inter VLAN routing.

And the way it does this is by creating SVIs, or switch virtual interfaces on the layer 3 switch.

These virtual interfaces allow data to be routed between VLANs by creating default gateways.

So, for example, when computer A on VLAN 10 wants to communicate with computer D on VLAN 20, computer A will send the data packet to the default gateway, which is the SVI assigned to VLAN 10.

And then the layer 3 switch will check its routing table just like a router would, and

then will forward the packet to VLAN20's SVI and then to computer D.

So, in a nutshell, that's how a layer three switch works.

Now, there are other devices that operate at layer three, and these are routers.

And routers only operate at layer three, but

layer three switches operate at both layer three and layer two.

So they basically combine the functionality of a router and a switch.

However, a layer three switch cannot do everything that a router does.

It doesn't have the complete routing capabilities of a router.

So, as a review, layer two switches forward data based on Mac addresses, while layer three switches route data based on IP addresses, but

it can also forward data based on Mac addresses.

Layer 2 switches cannot route data between VLANs, while layer 3 switches can.

Layer 2 switches require little to no configuration, while layer 3 switches require a more complex configuration.

And as far as price, layer 2 switches are relatively inexpensive, and

layer 3 switches are significantly more expensive.

And as far as speed, layer two switches are very fast, while layer three switches are slower.

So, guys, I want to thank you for watching this video on the difference between layer two and layer three switches.

Please subscribe and I will see you in the next video.