Is it possible to have different networks on the same port?

Question

Computer networks

Good afternoon. Please tell me, there is a need to provide Internet access to only one computer on the network and, moreover, so that it is not visible that the Internet is being used. The idea is something like this - take a hub, solder a portable wifi router into it with the ability to connect via doe and distribute the Internet to one port. The question is, is it possible? If so, how? As a nuance - all computers (and there are 10 of them on the network) must belong to the same network, the router (or possibly usb modem) should not be visible in the devices on the machine to which the Internet is being distributed. One person tells me with certainty that it is possible to raise two grids with different domains on the same port, but I doubt something. Or maybe someone knows some other sophisticated ways? -)
Give pliz advice.

Answer 1

a bunch of solutions: vpn, proxy port forwarding, etc.
Write directly what you need without smart words.
do you have access to servers, routers and other network nodes, etc. ??
who monitors the network / who should not be able to see that one computer is tyrnet ??
etc. etc.

Answer 2

Why shouldn't there be internet on computers at all?
This is not a technical problem and solving it with technical means will cost more in the future

Answer 3

this is a hub in which a wifi router with LAN and 4g support is placed inside.

Oh God, what only the school does not reach ...
Where are you, sorry, going to find a hub ? In 2019? Do you at least roughly know what it is and why it is? Yes, it was theoretically possible to insert a modern 4G wifi router into it - the hubs were healthy :)

Answer 4

роутер(или возможно usb модем) не должен быть виден в устройствах на машине на которую идет раздача интернета

The Internet is either there, then it is visible, or it is not, of course not visible.

Answer 5

Guys, everyone, thanks for the flattering comments and answers. Glad everyone showed off their knowledge and skills! The issue is resolved - a wifi router was built into the switch and its power was connected to one of the ports through a microswitch. I insert a cable with a network into this port, there is Internet, I plug it into another one, the router turns off .. Happy holidays everyone.