Connecting the router to the server. How to organize?

Question

Iron

Hello.
1. There is a local area network. Multiple vpn connections. A zoo of various PCs with different windows.
2. There is a router. Powerful PC (domain controller). A bunch of modems (Internet, vpn)
3. Task:
Global network -> router -> domain controller (powerful PC)
The router should be left in case of emergency.
How should I connect the "domain" to the router (at the wire level) in order to drive traffic through the router and the domain.
I confess, I'm not very good at it. Please tell me what, how and where. What to read. What to pay special attention to.
The main task is to introduce a domain controller.
On which it will be possible to flexibly configure user rights, backup, perhaps - hosting server applications.
Thank you for your attention.

Answer 1

Act consistently.
A domain is an abstraction for grouping a group of computers and assigning roles. Abstraction can be even on the Internet, even locally.
Have you installed a CD? Great, you don't need to connect it to the Internet at all. There is nothing for him to do there.
Take patch cords, connect your CD to your switch (router), check the network on it. That's it, your CD is already in your network, however, the traffic is not "driven" anywhere yet. When entering a domain, local computers will find the CD if it is configured correctly.
Now enter client computers into the domain, and enjoy the process.
It is already available if CD is installed and local computers are entered into the domain.
I do not recommend, make a distinction between roles, both for users and for computers.
Not necessary! There is a main task on the CD, it should be occupied only by it.