DUE with YUN

I am doing one project using for Arduino boards. Basically I have 2- Arduino YUN and 2-Arduino Due with Ethernet shield. As yun has inbuilt Wifi system, I connected Yun to wifi and configured it, it was successful. But now,

My questions is: Can I do connection between Arduino Due and Arduino Yun using Ethernet cable and pass data in between them, if yes then how ?

I have another question on broader level: I brought a FL Switch SFNB 8TX, and wired all the arduino boards with Ethernet cable to this switch. But I am unable to use it as communication between them ? Can you please let me know if I need to configure something or how to proceed further? Even a toy “code” working would be fine, say sending a alphabet from due to yun and then displaying it in the console using yun.

Please help.

Thanks in advance.