> The DNS settings on sa-vm1 are managed by ASF Infra team via Puppet and have 
> been set like this for years ever since the server was built new.
> 
> sa-vm1:/etc/resolv.conf
> nameserver 8.8.8.8
> nameserver 8.8.4.4

A side note: if we are running any RBL tests on that machine, 8.8.8.8 & friends 
may not be the best choice.

> 
> Interestingly, if I run digs from the server I see both the old and the new 
> IP:
> 
> davej@sa-vm1:~$ dig @8.8.8.8 sa-update.dnswl.org +short
> 116.203.4.105
> davej@sa-vm1:~$ dig @8.8.8.8 sa-update.dnswl.org +short
> 78.47.167.123

I flushed DNS cache at Google some 24 hours ago at 
https://developers.google.com/speed/public-dns/cache, and still it seems to 
show stale data. 

> But this site shows consistent DNS all around the globe:
> 
> https://dnschecker.org/#A/sa-update.dnswl.org 
> <https://dnschecker.org/#A/sa-update.dnswl.org>

That IP is also not in the zone file any more.

> I am only seeing minor DNS hosting issues that shouldn't cause any problems:
> 
> https://intodns.com/dnswl.org
> 
> - zone-ns3.dnswl.org should be added at the registrar as a name server for 
> consistency

Only the glue was added to the parent, not the NS entry itself. Thanks, fixed.

> - I would recommend NS record TTLs be 86400 (1 day) and A record TTLs of 3600 
> or 7200.

Indeed, that makes sense. Fixed.

> (SOA) - Any particular reason why the serial isn't in the standard format of 
> YYYMMDDnn?  What you have now should be fine.  Just curious.

Yes :) We create the zone from source files and thus need to automatically 
create the SOA serial. And this being in a makefile, having a daily 
incrementing „nn“ is not trivial. That’s why we have

SOASERIAL=`date '+%y%m%d%H%M‘`

> This problem might clear up at Google's DNS servers in Europe soon. Google 
> does some "special logic" to try to fix broken authoritative DNS servers that 
> I have seen keep zones and previous records alive on the Internet when a bad 
> change is made.  In this case, I am not seeing anything that bad wrong and 
> the problem doesn't show up in the US like it is in France where sa-vm1 is 
> hosted.

8.8.8.8 & friends are handled differently for most DNSxL zones, because 
otherwise freeriders will hind behind those resolvers. In our case, they see a 
zone which is slightly different from the rest (basically without NS records 
for the list.dnswl.org <http://list.dnswl.org/> zone). 

# dig txt amiblocked.dnswl.org @8.8.8.8 +short
"yes"
"You are blocked from using list.dnswl.org through public nameservers“

I asked on  https://groups.google.com/group/public-dns-discuss 
<https://groups.google.com/group/public-dns-discuss> for any further hints.

— Matthias


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