Domain Name Is Local. Windows uses the dot as the alias symbol for the local computer. In the Localhost page on the tool section click on Add A Virtual Host then you will be guided to the following page.
Even though you do not have to use a real domain name for your local devices you cannot simply use any domain name you want. However this can be a very bad idea for the following reasons. It will never be configured as a FQDN and as such your custom local names will never conflict with existing external addresses eg.
Split DNS is when you have two separate DNS servers managing the exact same DNS Forward Lookup Zone increasing the administrative burden.
It will never be configured as a FQDN and as such your custom local names will never conflict with existing external addresses eg. Our tool will allow you to search the WHOIS for most top level domains in order to learn the registrant information as well as the nameservers and associated IP addresses. It will use the local account with that username. When trying to join the Windows Server 2008 R2 machine to the domain by specifying the fully qualified domain name FQDN in the domain join UI the operation fails and you receive the error.