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What is the difference between a Layer 3 switch and a Layer 2 switch?
Differences between Layer 3 switches and Layer 2 switches: 1. Layer 2 switches work at the data link layer, and Layer 3 switches work at the network layer; 2. Layer 2 switches access based on MAC addresses, only forward data, and cannot configure IP addresses , and a layer-3 switch combines layer-2 switching technology with layer-3 forwarding functions.
The operating environment of this article: windows7 system, Dell G3 computer.
The difference between a layer 3 switch and a layer 2 switch:
Layer 2 switches work on Layer 2 (data link layer) of the OSI model, so they are called Layer 2 switches.
A Layer 3 switch is a switch with some router functions. The most important purpose of a Layer 3 switch is to speed up data exchange within a large LAN.
So what is the difference between Layer 2 and Layer 3 switches? The switch editor will introduce it to you.
1. Different working levels:
Layer 2 switches work at the data link layer, and Layer 3 switches work at the network layer. Layer 3 switches not only realize high-speed forwarding of data packets, but also achieve optimal network performance according to different network conditions.
2. The principle is different:
The principle of a layer 2 switch is that when the switch receives a data packet from a certain port, it will first read the source MAC address in the packet, then read the destination MAC address in the packet, and look up the corresponding port in the address table , if there is a port corresponding to the destination MAC address in the table, copy the data packet directly to this port. The principle of the three-layer switch is relatively simple, that is, one route is exchanged multiple times. Generally speaking, it is the first time that the source-to-destination route is performed. The three-layer switch will transfer this data to the second layer. Fast switching is possible from source to destination.
3. Different functions:
Layer 2 switches access based on MAC addresses, only forward data, and cannot configure IP addresses, while Layer 3 switches combine Layer 2 switching technology and Layer 3 forwarding functions, that is to say, Layer 3 switches are based on Layer 2 switches. The routing function has been added to it, and the IP addresses of different vlans can be configured, and the communication between different vlans can be realized through three-layer routing between vlans.
4. Different applications:
Layer 2 switches are mainly used in the network access layer and aggregation layer, while layer 3 switches are mainly used in the core layer of the network, but there are also a small number of layer 3 switches used in the aggregation layer. The following figure is an actual application example of a layer 3 switch .
5. The supported protocols are different:
Layer 2 switches support physical layer and data link layer protocols, such as Ethernet switches and layer 2 switches. The functions of this hub HUB are similar, while layer 3 switches support physical layer, data link layer and network layer protocols.
The above is the detailed content of the difference between a layer 3 switch and a layer 2 switch. For more information, please pay attention to other related articles on the php Chinese website!