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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 ( for base server, 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 (

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 ( 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 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 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).

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"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" - Of course not, because the internal server is authoritative for the internal zone, not the external zone. What is it exactly that you're trying to achieve? –  joeqwerty Nov 23 '12 at 1:51
It sounds like the external DNS is working correctly then. What you need to do is to configure port forwarding on your router/firewall to forward HTTP/HTTPS traffic to the internal ip address of the web server. –  joeqwerty Nov 23 '12 at 2:28
You're getting things mixed up. Your internal DNS server resolves DNS queries for your internal clients and for your internal DNS zone. The external DNS server resolves DNS queries for your external DNS zone. Neither one has anything to do with forwarding web traffic to your web server. The DNS servers resolve your FQDN to an ip address. An external web browser would use your external DNS server to resolvbe the FQDN to an ip address, then it trys to connect to that ip address, which needs to be forwarded from the router/firewall to the web server. –  joeqwerty Nov 23 '12 at 2:43
It doesn't work that way at all. The external browser opens up to www.mydomain.com, which is then resolved by your external DNS server to the external ip address allocated to you by your ISP. Once the external DNS resolution happens then the brower knows that www.mydomain.com resolves to, which is then routed to your ISP (because they "own" - which is allocated to you), the ISP then routes to your router, which then needs to port forward to No internal DNS resolution occurs. –  joeqwerty Nov 23 '12 at 3:20
I'm assuming you would need some type of proxy to forward HTTP traffic to multiple internal ip addresses from a single public ip address. I've never worked with any type of proxy so I can't help there. What I can suggest is that instead of using multiple IIS servers why not use a single IIS server and host multiple web sites on it using host headers to differentiate between them. That would only require a single public ip address and a single internal IIS server. –  joeqwerty Nov 23 '12 at 4:16

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