Why does a non-delegated sub-domain work?

[Daniel McDonald]

On 5/7/12 11:32 AM, "M. Meadows" <sun-guru at live.com> wrote:

>  
> So ... if we have
>  
> exacttarget.com delegated to ns1 and ns2.exacttarget.com nameservers
>  
> and ... we manage the s6.exacttarget.com zone file from ns1 and
> ns2.exacttarget.com
>  
> but we don't delegate s6 in the exacttarget.com zone file ... forgot to enter
> it in the zone file ...
>  
> how is it that s6.exacttarget.com and its contents resolve properly from
> everywhere?

Because bind can't distinguish between a query for s6.exacttarget.com from
the exacttarget.com zone and a query for s6.exacttarget.com  in the
s6.exacttarget.com zone, so it employs longest match and returns the
appropriate information.
  
> Seems BIND is helping us out behind the scenes somehow. Right?

Bind is hiding your configuration error, yes.  It won't work with DNSSEC and
might fail if you have a secondary for s6.exacttarget.com that is not also
authoritative for exacttarget.com



-- 
Daniel J McDonald, CCIE # 2495, CISSP # 78281