Planning internal DNS

Question

I am planning a new DNS names structure inside of our corporate network. We have external registered DNS name (e.g. example.com) and internal-only not existing name (e.g. exampleinternal.local). Everything internally is hosted on Windows 2012, DNS server + AD (one domain).

Now we would like to use only our external name. The idea is to create the domain under internal.example.com and make it the root of our internal DNS. This would mean that all internal clients will resolve into host.internal.example.com and they will be kept by our internal DNS server. At the same time we have other hosts, like www.example.com or something.example.com which are kept on the registrar's DNS server.

Thus I have a question. In case we would like to use this schema (domain delegation is not allowed on our registrar), would it be resolved correctly by our internal DNS server?

For example: 1. Client machine (inside our network) is asking for internal service: mypage.internal.example.com This is for sure will be resolved by our internal server into local IP

2. Client machine is asking for external service: www.example.com Would our internal DNS server forward request to the ROOT servers or Forwarders in this case? Are there any requirements for forwarders (do we need to setup our registrar's NS as forwarder)?

Thank you for answer.

Answer 1

It depends on how you set up the interal zone.

If you create an internal DNS zone for the child domain your internal server will only be authorative for the child domain. As explained here.
This way your external DNS is still authorative for the parent domain.

Another way of working (which is more fiddly but I've actually had better results with it) is to duplicate your primary zone internally.
And manually assign the IP addresses that need to point to internal IP addresses.