Re: DNS A record, required?

On 23 Oct 2009, at 13:46, DAve wrote:
> Good morning.

Drifting onto evening here.  Better get breakfast. :-)

> I have been asked by my co-workers and sales why I always create a A  
> record for new domains we host instead of a CNAME.
>
> The issue I run into lately with some domains is that a client has a  
> website with a industry host such as frank.relator.com and he wants  
> to have DNS point www.frank.com to frank.relator.com with a CNAME.  
> The client does not want an A record for frank.com. Or, they want a  
> CANME directing to another domain.
>
> Somewhere, in a class far far away, I was taught a DNS zone had to  
> have a A record to function properly. I can't seem to locate  
> anything in the RFCs.
>
> Am I wrong?

The rules are quite simply that you can't put a CNAME at a point of  
delegation.  And a zone will function just fine with only delegation.   
So yes you were mistaken, a zone does not need anything in it apart  
from that delegation, including A/AAAA records.  The delegation exists  
at the apex of the zone, where it meets the GTLD/CCTLD servers, and  
unfortunately there you cannot put your CNAME to another host (you can  
only use static A/AAAA).  This means most thirdparty-hosted sites only  
have the www CNAME to them and cannot support without the WWW prefix.

Cheers,
Sabahattin