intelligent selection of forwarders?
qralston+ml.bind-workers at andrew.cmu.edu
Thu Aug 15 20:16:22 UTC 2002
On Wed, 14 Aug 2002, Cricket Liu wrote:
> > The 4th edition of "DNS and BIND" contains this comment on forwarder
> > selection (page 270):
> > On BIND 8.2.3 name servers, you don't need to list forwarders
> > more than once. These name servers don't necessarily query
> > the forwarders in the order listed; they interpret the name
> > servers in the list as "candidate" forwarders and choose which
> > one to query first based on roundtrip time, the time it took
> > to respond to previous queries.
> > (The last sentence of the first paragraph doesn't parse;
> I beg to differ. [...]
Ok, I see now the meaning that was intended. (I wasn't expecting an
appositional explanation of roundtrip time; it seemed like it was
describing a second measurement that BIND was conducting in order to
discriminate among servers which had approximately the same network
> > So, my question: what version of BIND 9 implements the more
> > intelligent forwarding? If the answer is "none", then is there an
> > estimate when (as in, what version) this feature will be added?
> The answer is none. Maybe someone at Nominum can give you an
> estimate of when the feature will be added.
Thanks for the info.
Honestly, we don't care a whole lot about the load-balancing aspect of
this feature (i.e., BIND finding the best forwarder to use). What we
*do* care about is having rapid failover from a failed forwarding
James Ralston, Information Technology
Software Engineering Institute
Carnegie Mellon University, Pittsburgh, PA, USA
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