'dig -t any ...' question

[Jim Reid]

>>>>> "Ladislav" == Ladislav Vobr <lvobr at ies.etisalat.ae> writes:

    Ladislav> what's so special about ANY? 

Nothing. You just don't seem to understand what it means. A QYTPE of
ANY means "give me whatever RRs you have for this name". That's all.
See my earlier posting for more info.

    Ladislav> Why any recursive servers don't do it's best to satisfy
    Ladislav> the recursive client with the reply from the authoritative
    Ladislav> server, that's why we call it recursive right?

Wrong. We call it recursive because the server is able to recursively
make iterative queries to resolve a query on behalf of some client.
It doesn't mean the server does that: it can answer from its cache
which might or might not have been populated with data returned from
earlier queries to authoritative servers. No assumptions can or should
be made about how a recursive server provides answers. It should of
course interrogate authoritative servers when nothing has been
cached. But that cannot be guaranteed. And even if it does query
authoritative servers, the answer might not be correct. The DNS is
loosely coupled remember. It can take time for a zone's authoritative
servers to converge on the same copy of the zone data after the zone
gets updated. They don't all update the zone simultaneously.

You seem to think that an ANY QTYPE means a server must retrieve every
RR for the name. That's not the case. In fact this is impossible. The
master server could change the RRs immediately after answering your
hypothetical EVERY query before that reply gets back to the client.
It's not even the case that a server must query an authoritative
server in order to respond to an ANY query.

Remember too that one of the key strengths of the DNS is caching. In
some sense this means that recursive servers are lazy. They'll answer
from cache every time unless there's nothing relevant in the cache and
they're forced to resolve something. This is why people need to think
carefully about TTL values. How many times have we seen postings here
where there's been a long-lived TTL for a web or mail server that then
gets renumbered and the poster whines that traffic still goes to the
old address even though they've updated the zone?

    Ladislav> to do this kind of work for the
    Ladislav> client, how can it take answer from the parent and
    Ladislav> consider the task done?

Because that's how the DNS works.

    Ladislav> I have problem with ladislav.name.ae

         .... snipped ....

This appears to be either a wierd local set-up or else you have a
misunderstanding of what's going on.