Does not sound to be DNS related since you are trying to access the page via its public IP address. When you type in an IP for the URL, there is no DNS lookup. If you are unable to access the public IP from inside your network, its most
likely NAT related. Many of the consumer based NAT routers do not allow for accessing the PUBLIC ip which maps back to a private IP, from inside the network.
Does your webserver have a public IP configured, or is it a private IP, just NAT'd via your internet router?
For DNS, you would simply create a host record on your internal zone, then map that record to the private IP address of your web server.
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