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What is the difference between a Layer 3 switch and a router?
1. Different main functions
A Layer 3 switch is a switch with some basic routing functions, and its main function is still data exchange. It has both data exchange and routing and forwarding functions, but its main function is data exchange.
A router has only one major function: routing and forwarding.
2. The applicable environment is different
The routing function of Layer 3 switch is relatively simple. It mainly faces simple LAN connection.
It is used in the local area network in the main purpose is to provide fast data exchange function, to meet the LAN data exchange frequent application characteristics.
In order to meet the needs of different types of network connections, the router’s routing function is more reflected in the interconnection between different types of networks. Its main function is routing and forwarding.
It applies not only to Lans of the same protocol, but also to Lans and Wans of different protocols.
3. The performance is different
From the technical level, there are obvious differences between router and layer 3 switch in packet switching operation.
Generally, the router performs packet switching based on CPU, while the layer 3 switch performs packet switching through hardware forwarding.
After the Layer-3 switch routes the first data flow, it generates a mapping table (hardware forwarding table) of MAC addresses and IP addresses. When the same data flow passes again, it passes through the hardware forwarding table directly at Layer 2 instead of the CPU to calculate the forwarding path, which improves the efficiency of packet forwarding and realizes fast forwarding.
The forwarding of the router uses CPU to calculate and forward routes, and all packets need to be calculated by CPU before forwarding, so the forwarding efficiency is lower than that of the switch. Now the router also has a hardware forwarding table, but the first packet that passes still needs to be calculated by CPU.
What is the difference between a Layer 3 switch and a router?
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