>>Now I am trying your suggestions on a Windows 10 Pro PC. Installed all components and can run a test.aspx.
>>
>>1. The result of nslookup dell2020:
>>Server: Linksys11447 (I think this is my router) && Yes
>>Address: 192.168.1.1 (I think this is the address the router assigns to this Windows 10 PC) && No, it's the router's LAN IPv4 address
>>*** Linksys11447 can't find dell2020: Non-exisent domain.
>>
>>2. As I said above, the test with localhost works.
>>
>>3. When I replace the localhost with the computer name (dell2020) http://dell2020:8080/test.aspx
>>I get message:
>>dell2020's server IP address could not be found.
>>
>>What do you think is missing on this Windows 10 in order to set DNS to recognize the computer name, Dell2020?
>>
>>UPDATE:
>>On this site I disabled Anonymous Authentication and enabled Windows Authentication. The test.aspx with localhost correctly returns IsAuthenticated True. And the test.aspx page shows that (Dmitry, me) is logged in.
>>Everything correct.
>>Then I did ipconfig and see that the IPv4 is 192.168.1.141. So I replaced the localhost with 192.168.1.141.
>>Now, when I try to browse to test.aspx I am prompted, by Windows Security, to login using User Name and Password. Even though I (Dmitry) am the admin on this PC.
>>Pretty much the same that I was getting on the customer VM server. When browsing to the test.aspx page using the server name, the access not allowed unless user enters User Name and Password.
>
>In a typical home network, host (computer) names aren't added to local DNS by default, so they're not resolvable. For testing purposes usually the simplest thing is to modify Windows' HOSTS file: https://support.rackspace.com/how-to/modify-your-hosts-file/ . Your computer probably uses DHCP to get its LAN IPv4 address. If after a restart it gets a different address, you will need to update your HOSTS file. You can avoid this issue by switching your computer to a static IP address, either configured within Windows, or (more elegantly) via a DHCP reservation in your router. The latter always hands out the same IPv4 address to your computer when your computer asks for one.
>
>As for differing results when using IP addresses in the URL: I suggest keeping your eye on the ball, and testing only those scenarios which will be used by your customer. Others may be of academic interest but are a hindrance in getting things done.

Thank you.