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My DNS is running in a split DNS scenario.

Both publically and internally we have the same domain. Lets call it

When an internal user goes to they get a different response to the outside world. Both zones are hosted on seperate systems. However some things are only publicly available and not internally. These things are very dynamically changing. is only on the DNS internally is only on external DNS

I understand that there is a risk of leakage, but this is something I can, for the time being, live with.

What I need to know is if it is possible to use bind to have the internal zone (pulled out of AD dynamically) queried first and when this zone doesn't resolve what the user is seeking, that bind then pushes this query externally and stores it?

If Bind can't do this - can Unbound? And if so, how?

share|improve this question
Can you put your external record that in a sub-domain (perhaps In your AD delegate that sub-domain to the outside. Then use a cname on both the inside and outside to point at – Zoredache Jul 29 '13 at 17:14
I have 100's of internal sub-domains and the same externally. The internal ones are dynamic, as in AD but externally not. I simply need a way to dynamically update the internal zone in Bind (which is easy) but when Bind can't find say internally, will reference externally, where it probably is there. Now can Bind do this or should I use unbound or dnsmasq? – Matthew Jul 29 '13 at 19:14

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