get reverse lookups cached

[Kevin Darcy]

test1test at my-deja.com wrote:

> Hi all,
>
> first sorry for my name, privacy reasons,
>
> second a newbie question, we run named (8.2.3-T5B) on linux (SuSE 7.0),
> a 'caching-only' nameserver, and get correct 'non-authoritative' answers
> on repeated queries for host names. Repeated reverse lookups - those for
> ip numbers - are not signed as 'non-authoritative', also they
> seem to be cached, the dialin connection stays 'off' when repeating a
> query.
>
> Anyone able to shed some light on this?

Well, a non-non-authoritative answer is, by the double-negative rule, an
authoritative one. The simplest explanation is that your nameserver happens
to be authoritative for whatever reverse zone contains the records you were
querying. Either that, or the TTL's on the records are so low that they are
expiring from the cache between queries and the nameserver keeps having to
fetch them from authoritative servers.

> Third another question, is it possible to configure named *not* to
> connect to the internet on startup, but only when really needed?

No. The BIND 8 code always wants to "prime" (query the root servers to get
a good root NS list) immediately, whenever the nameserver starts. I am told
it would be next to impossible to change this, given the state of the
BIND 8 code, but offhand, I don't see that BIND 9 supports "deferred"
priming either. I'm sure that would be a nifty feature for dial-on-demand
setups...


- Kevin