The switch cannot communicate when it is just powered on.

Analysis: Since this switch is a network management switch, in order to avoid the existence of topological rings in the network, which can lead to network paralysis, the network management switch enables the spanning tree protocol by default. In this way, even if there is a loop in the network, one path will be retained and other links will be automatically cut off. Therefore, when the switch is powered on and started, each port needs to enter the listening, learning and forwarding state in sequence, and the qualification process takes about 3-5 minutes.

Solution: If you need to quickly implement data forwarding after the switch is powered on, you can disable the extension tree protocol, or set the port to PortFast mode, but it should be noted that although these two methods omit the port detection process, once the network device generates a topology ring, it will lead to network communication paralysis.