Differences between Layer 2 switches and Layer 3 switches

The specific differences between Layer 2 switches and Layer 3 switches are as follows:

First of all, it works in different ways.

Layer 2 switching technology has matured. Layer 2 switches is a data link layer device, which can identify the MAC address information in the data packet, forward it according to the MAC address, and record these MAC addresses and corresponding ports in an address table.

Layer 3 switches are switches with some router functions. The most important purpose of Layer 3 switch is to speed up the data exchange in large LAN, and its routing function is also for this purpose, which can be routed once and forwarded many times. Conventional processes such as packet forwarding are implemented by hardware at high speed.

Second, the working methods are different.

The traditional switching technology runs in the second layer data link layer of OSI network standard model, while the three-layer switching technology realizes the high-speed forwarding of data packets in the third layer of network model, which can not only realize the network routing function, but also achieve the optimal network performance according to different network conditions.

The basic difference between Layer 2 and Layer 3 switches is that Layer 3 switches have routing function and can be regarded as network layer devices (of course, they can also be regarded as Layer 2). Layer 2 switches are data link layer devices and have no routing function.

Third, the exchange methods are different.

Three-layer switching is put forward relative to the traditional switching concept. As we all know, the traditional switching technology works in the second layer of OSI network standard model-data link layer, while the three-layer switching technology realizes the high-speed forwarding of data packets in the third layer of network model.

The three-layer switching technology is: two-layer switching technology+three-layer forwarding technology.

Extended data:

Working principle of the switch:

When the switch is powered on, it will automatically establish a port address table, also called MAC address table. It will record the MAC address of each device and which port it is connected to. It will have automatic learning function. If there is no address at first, it will read and record the MAC address of the device port that sends the information every time it passes through the switch.

If another device sends information to the device next time, it will send it directly. In the most common case, the forwarding principle is as follows: when a switch receives an Ethernet frame data, it will compare it with the port address table that the switch has learned, and if there is a port address in the table, it will forward it directly at the corresponding port.

If it is not in the table, the same message will be broadcast to each remaining port.

National Security Agency-General Secure Access Configuration of Access Switches

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