Principles of the switch
The switch works on the second layer of the OSI Reference Model, the data link layer. The CPU inside the switch forms a Mac table by matching the MAC address to the port when each port is successfully connected. In future newsletters, packets sent to the MAC address will be sent only to their corresponding ports, not to all ports. Therefore, the switch can be used to divide the data link layer broadcast, that is, the conflict domain, but it can not divide the network layer broadcast, that is, the broadcast domain.