Re: Reducing the 2560 negative cache default

On 17 May 2010 19:49, Matthew Dempsky <[email protected]> wrote:
> On Mon, May 17, 2010 at 7:51 AM, Sabahattin Gucukoglu
> <[email protected]> wrote:
>> The question was, must a Z record be used in order to change the value
>> of min (that's Minimum, or in these enlightened times, Negative Cache Lifetime)?

Actually, that wasn't quite how the original question was worded..  which
sort of side-tracked me.  ;o)

'Negative ( as in no positive response ) Cache Lifetime' is certainly a more
succinct description  of what I understood 'minimum'  to be all about.

> Yes.  That field is not available with a "." line.

Indeed.

>> Which begs the question, what does dnscache use "min" for, the former or the latter?
>
> The fields in the Z line go directly into the SOA record.  (Also,
> dnscache never touches a data or data.cdb file directly.)

Not quite what,

http://cr.yp.to/djbdns/dnscache.html

says?

<snip>
dnscache does not cache SOA records. However, it does use SOA TTLs to determine
 cache times (up to an hour) for zero-record responses and nonexistent domains.
</snip>

But under,

RESPONSES TO DNS CLIENTS

it does state,

<snip>
dnscache's responses are generally much smaller than BIND's responses. They do
not include authority records (NS records of the source name servers and
 SOA records for negative answers) ...
</snip>

Regards,


Chris.