How connect the relay node and the block producer node

Hi at all, i’m reading the cardano documentation to lean how to make a stake pool.
But i’m not understanding really well the topology of the network, my first idea it was to connect to the internet only the relay node, and keep the block producer node not connected on internet (with a different ip class and only connected to the relay node). I’ve attached an image to explain better what i was thinking.
Could you guys suggest me or explain me how did you connected physically your stake pools?

I do not run a stake pool, so take my answer with a grain of salt.

Its my understanding that the recommended configuration is a block producer and two relays and that the relays are geographically distributed. The are all “on the internet” but only the relays are public.

Hope this helps.