I'm currently trying to set up a home development server (details below). Unfortunately, any time I try to access a DNS entry on a computer whose network card doesn't explicitly reference my internal DNS server I can't resolve the specific address.
Domain Setup: Domain, mydomain.net, is hosted at GoDaddy. Its nameservers point to DynDNS. DynDNS has the following records:
mydomain.net A-record My Home IP
www.mydomain.net Alias (CNAME) mydomain.net
Server Setup: I have a single server running Windows Server 2012. On this server I run a virtual machine for IIS. The base instance runs Active Directory services, DNS, and Hyper-V. In the IIS VM I run IIS. Each has its own distinct static IP (192.168.0.100 for base server, 192.168.0.105 for IIS).
Local DNS Setup: I have a DNS service running on the base server. This contains the A records for the domain, as well as test.mydomain.net. test.mydomain.net points to the IIS IP (192.168.0.105).
Router Setup: All of my home network is behind a single modem/router. I have the DMZ set up for the base server's IP (192.168.0.100) and I'm also forwarding port 80 to the base server's IP.
What works: If I access test.mydomain.net from a computer which I've configured to use the 192.168.0.100 DNS server everything works fine. test.mydomain.net resolves as the IIS server and IIS loads and displays the page properly.
What doesn't work: If I try to access test.mydoman.net on any machine external to my network, or even on a machine internal to my network that doesn't use 192.168.0.100 as the DNS, test.mydomain.net doesn't resolve. If I ping test.mydomain.net it doesn't even resolve the correct IP.
What I've tried: I've added another A record in DynDNS for test.mydomain.net that points to my home IP. When I do this and then ping test.mydomain.net from an external machine it correctly resolves my home IP but it never resolves any further. This likely means that the request is never correctly sent to (or in some other way processed by) the base server (which is running the DNS).