Why is there no access to the local system when the Internet is turned off?

Question

Computer networks

Good afternoon.
The situation is this: there is a server, an ecm system is deployed on it, work with it goes through the web. When external communication channels (Internet) are disconnected, the system stops working (503 error is written in the logs). There is an SSL certificate, https://domainsystem.ru - does not work on ip https://192.168.0.1 and there is no connection either.

Could this be related to the certificate or is the problem something else?

Answer 1

It is necessary to look at what the software that is on the web server is listening to. The domain will not work, because DNS servers are not available.
And it shouldn’t let you in by IP, because you need https, and it is tied to a certificate that is tied to a domain ...

Answer 2

DNS resolution of the domain name system.ru stops working for you. And apparently you go to your internal server with access to the outside.
Since it is not clear what you have inside - the solution may be different - from creating a zone in the internal DNS, looking at the internal interface - to creating an entry in hosts

Answer 3

Or is the problem something else?

Certainly in another