How to configure a proxy on a specific outgoing port?

Question

Computer networks

One of the computers on the network has Internet access if you configure a proxy like 10.XXX:3128. All the rest are on the same subnet, but they do not have Internet access, the proxy server uses an ip white list. All available manuals for configuring proxy servers have how to configure a proxy to accept connections on a specific port, but there is no how to configure an outgoing port. Is there a way to set up Internet access on other computers? Proxy vpn, any vartants will do.

Answer 1

Make forwarding from one of the addresses added to the white list. Traffic forwarding + masquerading.

Answer 2

Well, in general, to set up a "transparent" proxy, you must initially configure it as a "transparent" proxy. But then a lot of work will have to be done with routing.
Enikey of the branch is unlikely to be allowed to do this, because there is a great chance to put the entire network, at least, of the branch. Yes, and the proxy was most likely created by the security forces to be able to monitor where people climb