I'm designing a PCB and it requires me to receive three Ethernet ports, and output one of them to the forth port. Then it goes from Ethernet to a USB converter, and goes to the system.
My question is, do I need a PHY? The systems entering into the three ports have PHY on them. Going to magnetics, and then to the switch. But, when one port goes the the output port, do I need to do anything else? I'm no expert in Ethernet, this is the first time I've dealt with a switch for Ethernet.