I know this is incredibly basic, but I'm completely new to a lot of this.

I've been able to set up an architecture for ROS nodes and subscribers, ie: node X subscribes to topic Y which has data published by nodes Z1 and Z2.

So far, all I'm using is a random number generator to get node X to print off 'received (random number) from node (z1 or z2)

I have no idea now, how to now connect these nodes into certain physical interfaces, for example, i have an ethernet cable connected to the computer that i want to read it's data into node Z1.

similarly, say i wanted to push the data that node X subscribes through an ethernet cable, how can i do that? I'm using an STM32 for the microcontroller.