query ip address

Joe Williams williams.joe at gmail.com
Wed Sep 13 21:03:05 UTC 2017


Thanks to asking around on twitter I think we have the why,
https://cr.yp.to/djbdns/namedroppers/20000220195445-21265-qmail@cr-yp-to

https://twitter.com/jedisct1/status/908072827890405376

On Wed, Sep 13, 2017 at 1:52 PM, Joe Williams <williams.joe at gmail.com>
wrote:

> Thanks for finding that Tom!
>
> On Wed, Sep 13, 2017 at 1:49 PM, Tom Samplonius <tom at samplonius.org>
> wrote:
>
>> dnscache is a pretty weird.  From the webpage at
>> http://cr.yp.to/djbdns/dnscache.html ...
>>
>>
>> “dnscache handles dotted-decimal domain names internally, giving (e.g.)
>> the domain name 192.48.96.2 an A record of 192.48.96.2."
>>
>>
>> So it looks like dnscache will return a the IP address back for any A
>> queries for a IP address.  And it looks like it returns a basically
>> infinite ttl.
>>
>> Why do you need this behaviour?  I used to use dnscache many years ago,
>> but dropped it when powerdns-recursor became available.  I never noticed
>> this “feature”, and never had anything break when it went away.
>>
>>
>>
>>
>> On Sep 13, 2017, at 1:17 PM, Joe Williams <williams.joe at gmail.com> wrote:
>>
>> Thanks for the reply Tom, I wish I knew why as well.  Right now I am just
>> trying to make my unbound config backwards compatible to not break code
>> that expects an answer for an IP address.
>>
>> On Wed, Sep 13, 2017 at 1:05 PM, Tom Samplonius <tom at samplonius.org>
>> wrote:
>>
>>>
>>> > ;; ANSWER SECTION:
>>> > 10.36.129.10.         655360  IN      A       10.36.129.10
>>>
>>>
>>>   Looking at this answer, I’m not sure why anyone would want this
>>> behaviour?
>>>
>>>   Is dnscache trying to dampen RFC1918 A queries by doing this?
>>>
>>>
>>> Tom
>>
>>
>>
>>
>
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