How is it possible to access a specific computer on the network if all computers are united in one organization into a single local area network?

Question

Computer networks

There is an organization that has about a hundred computers united in a single local network. All computers are connected to a single multi-port hub, which, in turn, is also connected to a wire from a server computer running UserGate Proxy & Firewall . Further, through a separate network card, the server is connected to a router, which includes a twisted pair of Internet. Thus, the server has two subnets, for the router (192.168.1.2) and for processing requests from other computers (192.168.0.1). All regular computers have:
1. IP address (192.168.0. 2...100 )
2. Subnet mask (255.255.255.0)
3. Default gateway (192.168.0.1)
4. Preferred DNS server (192.168.0.1)
No proxy is used (which is usually activated via Control Panel -> Internet Options -> Connections -> Network Settings )
This is the basic network configuration in an organization. Is it possible to somehow reach a separate computer from the local network if the entire network as a whole from the outside has one single, single static IP address?

Answer 1

You just need to forward ports

Answer 2

Usually they organize a VPN server inside the network, which is accessed from outside, and through VPN they already have access to any computer on the network. Open VPN for example.

Answer 3

Since "reaching an internal IP" actually means "reaching a specific service (port) on a specific internal IP", a NAT tunnel (otherwise known as "port forwarding") is usually made.
It is not clear from your description whether the Usergate server also performs NAT, or just routing. If doing NAT, then you need to decide if you need a second NAT, and if you do, then tunnel twice.
If you want to map ALL ports of one of the internal workstations one-to-one to a certain white IP, then you accordingly need a separate (second) white IP on this router and check if it can full NAT (the so-called full-cone NAT)