How to use the service inside the network and outside by one ip?

Question

Computer networks

Good afternoon.
There is a web server on one of network computers. There is a gateway connected to the Internet. How to access this web server using one ip address? Only address forwarding comes to mind, but how to do it with the built-in tools of Windows
ATP.

Answer 1

You can do port forwarding on the gateway: Windows Port Forwarding
By accessing the external address (gateway address) and the desired port, it will redirect the connection to the internal network to the port you need (probably 80). If there are some web services on the gateway that have already occupied port 80, when entering from an external address, you will need to specify a port other than 80.

Answer 2

It is more correct and more logical to use DNS names. Outside, register a domain like service.domain.ru with an A-record to the desired ip-address. On the internal DNS, register in the forward lookup zones the correspondence of the same name (service.domain.ru) to the already local address.
Clinging to a local web service by making a detour through the external interface of a router or a proxy server is, to put it mildly, a very dubious solution with a bunch of restrictions.