> On Nov 13, 2015, at 11:50 AM, Stephane Bortzmeyer <[email protected]> wrote:
> 
> On Thu, Nov 12, 2015 at 06:13:04PM +0000,
> Wessels, Duane <[email protected]> wrote 
> a message of 57 lines which said:
> 
>> As Mark pointed out, we can't use the SOA to make NXDOMAIN more aggressive.
>> 
>> For a name like foo.bar.example.com and an NXDOMAIN response from
>> example.com we can't assume that there would be a zone cut between
>> foo and bar.
> 
> Could anyone explain in detail why is it so? [I don't understand why
> the zone cut is important here: using the SOA does not depend on
> whether there is a zone cut or not.]
> 
> Let's say I query foo.bar.example to example's name servers. I get:
> 
> ...
> ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 64182
> ;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 8, ADDITIONAL: 1
> ...
> ;; QUESTION SECTION:
> ;foo.bar.example.             IN SOA
> ...
> 
> example.                      5400 IN SOA nsmaster.nic.example. 
> hostmaster.nic.example. (
>                               2222956935 ; serial
>                               3600       ; refresh (1 hour)
>                                ....
> 
> It can mean only one thing, that bar.example does not exist. How could
> it be different?
> 

If 'bar.example IN A 127.0.0.1' existed in the example zone, what would you 
expect
for the response to your query above?

DW



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