DNS Round Robin
Florian Weimer
fw at deneb.enyo.de
Mon Apr 25 23:11:14 UTC 2005
> My theory is as follows. The query causes the caching NS to get the two
> answers but the software stores them in numerical order. The default
> for bind is to "round-robin" so it choses the first (and thus the lower
> IP address) as the first value. Since the TTL is zero, the software
> then discards the data so it never gets to select the second value in
> its robin robin scheme.
>
> Does this sound plausible?
It's plausible. I would assume this behavior without looking at the
source code, too.
> Has anyone else observed this? Is it a bug or a feature?
It's a feature. Anything which discourages the use of TTL 0 is a
feature.
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