[dns-operations] Strange behavior of google public resolver

Taras Heichenko tasic at hostmaster.ua
Thu Apr 18 10:00:10 UTC 2019

Thank to all for the answers.

Viktor, I know that it is really old algorithm and that it must not be used. But this domain is out of my scope and
I can only strongly recommend to the domain's admin. That I did and do again and again. But the question was other.

I think that we have found the reason of such behavior. It is prices of dnsmadeeasy:

5M Queries /month за $30
10M Queries /month за $60
50M Queries /month за $1500.

I think that google exceed some rates and is blocked by dnsmadeeasy. And it gets answer
only from ba1.ns.ua. I have only one unresolved question. Does not google's recursive resolver
cache answers from authoritative servers? Why does it give right answer so rare?

> On Apr 18, 2019, at 12:46, Stephane Bortzmeyer <bortzmeyer at nic.fr> wrote:
> On Thu, Apr 18, 2019 at 11:46:28AM +0300,
> Taras Heichenko <tasic at hostmaster.ua> wrote 
> a message of 75 lines which said:
>> And sometimes I get answer
> Testing with RIPE Atlas probes show that, indeed, all other resolvers
> manage to resolve the domain, but often fails (but not always):
> % blaeu-resolve -r 100 -q NS --displayvalidation -x rv.ua
> Nameserver
> [ERROR: SERVFAIL] : 85 occurrences 
> [ba1.ns.ua. ns5.dnsmadeeasy.com. ns6.dnsmadeeasy.com. ns7.dnsmadeeasy.com.] : 10 occurrences 
> [TIMEOUT] : 1 occurrences 
> Test #20841694 done at 2019-04-18T09:37:09Z
> I think you'll have to report it to Google. I see no serious problem
> in your domain.
> (Of course, it would be better to move away from DSA, but it shouldn't
> make a SERVFAIL, just a lack of validation.)

Best regards

Taras Heichenko
tasic at hostmaster.ua

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