Which means I can skip the first question. Not all routers have this feature and fewer still have flash firmware to add it.
As to what you want to do, well isn't that something unrelated to the first 2 questions?
And frankly, the answer is no. IP networks should not do what you ask.
I would like to know more about client isolation, what can i do with that ?
Is all the routers can support this function ? (or after flash the firmware ?).
That i would like to do : i use a repeater to access internet, but all the machine connected on wifi by the repeater access to all the name of the computer connected. I would like to prevent this, and that all the computer connected on the repeater don't appear in the network. Only the repeater.