[BIND 8.2] Negative TTL not working ???

Mark_Andrews at iengines.com Mark_Andrews at iengines.com
Thu Nov 18 04:32:43 UTC 1999


> In article <199911170539.QAA18211 at bsdi.dv.isc.org>,
>  <Mark_Andrews at iengines.com> wrote:
> >	Go read RFC 2308 and look at the new use for the minimum field
> >	and why $TTL was added.  The answer above is a negative answer,
> >	and the TTL is correct.
> 
> In particular, the following from section 5:
> 
>    Like normal answers negative answers have a time to live (TTL).  As
>    there is no record in the answer section to which this TTL can be
>    applied, the TTL must be carried by another method.  This is done by
>    including the SOA record from the zone in the authority section of
>    the reply.  When the authoritative server creates this record its TTL
>    is taken from the minimum of the SOA.MINIMUM field and SOA's TTL.
>                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> 
> The interesting thing is that section 3 says that the receiver is supposed
> to use the minimum of the SOA's TTL and the SOA.MINIMUM field as the
> negative cache time.  It seems redundant for both the caching server and
> the authoritative server to perform the calculation min(SOA.MINIMUM, SOA'S
> TTL).

	The client side only needs to look at the ttl in the answer
	it receives.  If you feel the wording could be improved
	send the changes to namedroppers at internic.net.

	Mark
--
Mark Andrews, Internet Engines Inc. / Internet Software Consortium
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark_Andrews at iengines.com


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