[dns-operations] Strange behavior of google public resolver

[Stephane Bortzmeyer]

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 8.8.8.8 often fails (but not always):

% blaeu-resolve -r 100 -q NS --displayvalidation -x 8.8.8.8 rv.ua
Nameserver 8.8.8.8
[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.)