Say there is a physical UTP cable running from point A to point B.
At A there are two physically isolated devices, a1 and a2, each running their own network and unaware of each other's existence.
So there are two devices at B: b1 and b2.
Device a1 is supposed to be on the same network as b1. Device a2 is supposed to be on the same network as b2.
What is the simplest way to connect a1↔b1, a2↔b2 so that they share that one physical UTP cable but essentially run two separate "logical" (or "virtual") cables over it and don't conflict? (Assuming that reasonable speed trade-off is acceptable?)
Is there some sort of smart splitter that does that?
The only way that I currently know of is complicated: put devices a0 and b0 at each end, each having 3 network interfaces (0, 1, and 2) and connect them with the physical cable attached to interface 0 at each end. Configure two separate VPN networks inside a0 and b0, exposing them to interfaces 1 and 2 respectively. Plug:
- a1 into a0-1
- a2 into a0-2
- b1 into b0-1
- b2 into b0-2