[question] new bind option "max-recursion-depth"

Techs_Maru tecabu at gmail.com
Thu Dec 18 02:15:22 UTC 2014

Thanks to me to politely reply.

2014-12-17 15:16 GMT+09:00 Evan Hunt <each at isc.org>:
> On Wed, Dec 17, 2014 at 01:30:35PM +0900, Techs_Maru wrote:
>> However,
>> if the value of the default "7" would be the value that was created
>> based on the world data ?
>> ( Also for the default value of "max-recursion-queries 50;" )
> I haven't personally seen any real world queries go more than 4
> levels deep, but I wouldn't be surprised if there are a were domains
> out there that do.  7 seemed like a safe upper limit.
> The default max-recursion-queries value of 50, we got by testing with a
> sample of real-world resolver traffic.  It turns out it isn't quite right,
> though.  A limit of 50 works fine with a populated cache (which is
> how we were testing it), but if the server is just starting up and the
> nameservers for .com and .org and .net and so on aren't in cache yet,
> then it *can* take more than 50 queries to resolve a name.  (This turns
> out to be especially true on 9.10, due to changes in EDNS processing
> that affect how much NS glue we get from servers in the early stages of
> populating the cache.)  We'll be making some adjustments in upcoming
> maintenance releases to allow for this.
>> I want to know the recommended settings for everyone to values.
> I'd leave the defaults alone on BIND 9.9.  On 9.10, I might consider
> increasing max-recursion-queries to 100, but be prepared to back the
> change out when updating to the next release.  Or leave the defaults
> alone but be prepared for the possibility of some SERVFAIL responses in
> the first few minutes after server startup.

Sorry,Lack of knowledge,
9.10.X and 9.9.x QueryFlow is different ??

By the way,
value even in the case of dual-stack name servers is okay without changing ?


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