[dns-operations] Order of dropped queries when the maximum number of recursive clients has been reached

[John Kristoff]

On Fri, 28 Apr 2006 14:27:22 +0000
Paul Vixie <paul at vix.com> wrote:

> my reason for answering this here is that, apart from what BIND does,
> there is an interesting question, what's the best thing for a
> recursive server to do?  (if there's a case to be made, perhaps BIND
> could be encouraged to change its behaviour, along with other
> implementations?

If experience with routers tells us anything I think the current
BIND implementation is probably safest, if not the best approach.

I would be more interested in the querier's reaction to drops.  I
was under the impression, perhaps incorrectly, that most resolvers
have a relatively simple retransmission mechanism, sending some
number of retransmissions in short fixed interval to a list of
servers before giving up.

Would any more refined strategy, such as an exponetial back-off for
a server that is not responding or sending back errors just cause undue
delay in most cases?

John