What is the difference between a layer 3 switch and a layer 2 switch

Broadcast articles

What is the difference between a layer 3 switch and a layer 2 switch

The difference between a layer 3 switch and a layer 2 switch ：1、 The layer-2 switch works at the data link layer , Layer 3 switches work at the network layer ;2、 The layer 2 switch is based on MAC Address access , Only do data forwarding , And it can't be configured IP Address , The layer-3 switch combines the layer-2 switching technology with the layer-3 forwarding function .

This article describes the operating environment ：windows7 System 、Dell G3 The computer .

The difference between a layer 3 switch and a layer 2 switch ：

Layer 2 switch works in OSI The first of the model 2 layer （ Data link layer ）, So it's called layer 2 switch .

Layer 3 switch is a switch with partial router function , The most important purpose of layer 3 switch is to speed up the data exchange in large LAN , The routing function is also used for this purpose , Be able to route once , Forward many times .

So what is the difference between layer 2 and layer 3 switches ？ The switchboard editor will introduce you .

1、 Different levels of work ：

The layer-2 switch works at the data link layer , Layer 3 switches work at the network layer , The three-layer switch not only realizes the high-speed forwarding of data packets , It can also achieve the optimal network performance according to different network conditions .

2、 The principle is different ：

The principle of layer-2 switch is that when the switch receives a packet from a port , It will first read the source in the package MAC Address , Then read the purpose in the package MAC Address , And find the corresponding port in the address table , As shown in the table, there are and purposes MAC Port corresponding to address , Just copy the packet directly to this port . The principle of layer 3 switch is relatively simple , One route and multiple exchanges , Generally speaking, it is the first time to route from source to destination , The layer 3 exchange opportunity transfers this data to layer 2 , Then the next time, whether destination to source or source to destination, you can exchange quickly .

3、 Different functions ：

The layer 2 switch is based on MAC Address access , Only do data forwarding , And it can't be configured IP Address , The layer-3 switch combines the layer-2 switching technology with the layer-3 forwarding function , That is to say, the layer 3 switch adds routing function to the layer 2 switch , Different configurations are available vlan Of IP Address ,vlan Different can be realized through three-layer routing vlan Communication between .

4、 Different applications ：

Layer 2 switch is mainly used for network access layer and aggregation layer , The three-layer switch is mainly used for the core layer of the network , However, there is also a phenomenon that a small number of layer 3 switches are used in the aggregation layer , The following figure is a practical application example of layer 3 switch .

5、 Different protocols are supported ：

Layer 2 switches support physical layer and data link layer protocols , Such as Ethernet switch 、 Two-layer switch , This is the hub HUB It's about the same , The layer 3 switch supports the physical layer 、 Data link layer and network layer protocol .

The above is the details of what is the difference between layer 3 switches and layer 2 switches , Please pay more attention to php Other related articles on Chinanet ！