Questions about DNAME records

Chris Buxton cbuxton at
Tue Jun 16 14:40:14 UTC 2009

On Jun 16, 2009, at 1:37 AM, Braebaum, Neil wrote:
> What I was getting at - probably worded poorly - was say I wanted to
> provide resolution for something like:-
> if I'd previously created the DNAME record (	IN
> DNAME, would creating a SRV RR record in
> work as resolution for it?

Yes. The final and complete answer will be:	IN	CNAME	IN	SRV	... 4 fields here ...

> As to the forwarding thing, what I was thinking of, is that
> forwards out to internet DNS servers for external
> resolution

Unfortunately, that's a nonsensical assertion. A domain does not  
forward. A DNS server forwards.

> and it just so happens that is a namespace we
> use externally. So would it work in the scenario I've given, that if I
> wanted to provide resolution for (if it  
> works
> with the DNAME scenario I've described above), would other records for
> that aren't catered for in, be obtained by
> merit of forwarding? Or would the DNAME configuration  
> not
> allow it?

A DNAME record precludes child names. That is, you cannot have any  
names of the form "" and also have a DNAME record named  

> I guess what I'm wondering is that if is DNAMEd
> to and the records aren't in does the
> enquiry end there, or could / would the question be dealt with by  
> merit
> of forwarding to internet DNS servers?

If you have a DNAME record named, then aside from other  
records named, there cannot be any other records in the zone. No subdomains are allowed.

So if is hosted on the outside, and is  
internal, an internal resolver will see the external DNAME record (and  
related, synthesized CNAME records) and be able to resolve them inside (assuming it can find

If there is no external version of, then you're creating  
problems, because a DNAME record from a public zone to a strictly  
private zone will cause resolution for the public for names in the domain (except itself) to fail.

Unfortunately, if this explanation isn't clear, I would need to know  
exactly what you're trying to accomplish, probably including real  
names, in order to help further. My employer offers confidential DNS  
consulting service for a fee, if that would be useful to you.

Chris Buxton
Professional Services
Men & Mice

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