The switch network cable is connected to the user. However, the beginning does not indicate which port is for which machine. Now we need to change course. Only one. How to find
When all users are turned on, unplug the network cable on the computer that needs to be replaced, and that's the one that turns off the lights. If you can't turn on all users, you can test it with a signal tester. The specific method is to connect the tester to one end of the line to be changed and try it one by one at the other end.