Unable to get AAAA for www.revk.uk from some of our servers

[Phil Mayers]

On 24/12/14 17:08, Frank Bulk wrote:
> Except queries from 96.31.0.5 and 199.120.69.24 reliably return the AAAA
> while queries from 96.31.0.20 do not.  And we're all the same ISP, and in
> the one case, from the same /24.  I don't think Google is that granular. And
> we do have good IPv6 connectivity.

Yes, Google are that granular. See:

http://www.google.com/intl/en_ALL/ipv6/statistics/data/no_aaaa.txt

...which currently lists:

96.31.0.20/32            # AS53347 United States
96.31.0.31/32            # AS53347 United States

Google have been, AFAICT, silent on the specifics of how they generate 
their blacklisting. Presumably it's the fairly standard approach of 
correlating a web-bug to a unique hostname embedded in the google search 
page, received http requests, and received DNS queries. Google 
undoubtedly then do some stats magic - that is their thing, after all - 
and down-score resolvers which make the AAAA query but whose clients 
don't finish the HTTP request, above some threshold.

We had persistent problems in the past with our resolvers appearing in 
the Google blacklist, despite having excellent IPv6 connectivity. Google 
were unwilling to provide us any details that would have allowed us to 
identify the cause(s).

We eventually stopped paying any attention to it, and the problem went 
away by itself.

Possibly there are one or more clients with broken IPv6 using your 
resolvers, but without Google specifying the criteria which gets a 
resolver blacklisted, it's hard to know.

Frankly, I wish Google would ditch the AAAA blacklist. It is hiding 
problems that responsible operators would like to see and fix, just so 
that Google don't lose eyeballs (and ad revenue) :o/