Not liking the solution you have doesn’t mean you don’t have a solution.
Anyway, watch the playlist I sent, it’s a great overview of the OSI model with some other stuff. You mentioned not understanding some layers, once you do you will understand the limitations of the hardware you have.
You are basically asking for people to solve a solved problem, there’s no actual need for keeping the PCs separate since you control them both, and oh and you want it done cheap. A bespoke custom solution will not scale regardless if you need it to or not, you should know that.
https://hometechhacker.com/great-choices-for-opnsense-hardware/
A firewall device with as many ports as you need is your best bet.
I do need to segregate networks but I do not trust the operating systems running on these switches which can do L3 routing.
Ok, so you are trusting the PCs which you need to keep separate.
There’s no way to know if one of them is hoovering all the traffic from the other, if they are both connected to the same unmanaged switch.
https://youtube.com/playlist?list=PLjVwd8FlHBASO5vLBtMYNOzm8Q9DegSjO
Alternative lifestyle people are visionaries
Sequel to snowcrash right there
quieter, and uses way less power.
VERY IMPORTANT PAY ATTENTION TO THIS SENTENCE OP
It’s not well documented until it’s proven in court…