The level of a network switch is its position in the OSI network model. The OSI model determines the degree of intelligence and functionality of the device.
What is the switch layer?
In simple terms, this is the ability of a device to process the data that it receives more or less intelligently. If we consider the OSI model as a whole, we will see seven levels in it. Concerning switches, we are interested in the” lower floors ” of the model-levels 1 to 3.
Features of the first-level switch (L1)
This device works on the physical level. This means that it can process only electrical signals, without isolating or analyzing their information component. The L1 switch group includes hubs widely used in the past, repeaters, and other similar devices. Their advantages are the low price, minus — minimum functionality.
Features of the second-level switch (L2)
It works on the channel level. The layer two switches are capable of processing, not just electrical signals but also frames of information (so-called frames). It implements physical addressing logic based on the MAC addresses of transmitting and receiving devices.
Features of the third-level switch (L3)
This device works at the network level. In comparison with level 2 and level 3 switches, the latter wins — it is able to operate with the IP addresses of senders and recipients of information and build optimal data transfer routes. This is why the layer three switch has an alternative name-router.
Difference between layer 1, layer 2, and layer 3 switches
Let’s summarize the above:
- layer 1 switches are not capable of intelligent data processing — they only transmit electrical signals. At present, these devices are almost not used — they have been replaced by more advanced equipment;
- layer 2 switches identify devices by MAC addresses and transmit frames of information between strictly defined senders and recipients;
- layer 3 switches work with IP addresses and not just identify senders and recipients, but build optimal data transfer routes.