Over the last couple of competitions, this year and last year I have seen several teams using network switches wrong with their radios. What these teams do is plug their roborio into the port closest to the power port with a POE injector between the Rio and the radio much like photo 1 shows. Then they plug the switch into the second port on the radio then plug a Raspberry PI or Limelight into the switch. Other than allowing you to tether to your robot with more than 2 devices this does not fix the known bug of the second radio port not functioning occasionally.
This chiefdelphi post has ALOT of information about the topic and even recommended networking switches that would be good to use on a robot.
The correct way to connect the rio, radio, and another device like a limelight or a laptop for tethering would be to connect the rio directly to the switch and the switch to the POE injector and then the POE injector into the radio (the port closest to the power port). Then connect ANY other devices to the network switch. While this photo does not show the POE injector it can be added between the switch and the radio.
