Have we been opted out of IPv6 AAAA resolution?

Shumon Huque shuque at upenn.edu
Wed Jun 6 16:23:13 CEST 2012

On Wed, Jun 06, 2012 at 02:32:40PM +0200, Bernhard Schmidt wrote:
> Am 06.06.2012 14:26, schrieb Shumon Huque:
> Hi Shumon,
> > Same here (University of Pennsylvania) for google. And it's 
> > only our primary resolver that isn't receiving AAAA. The
> > others are fine.
> > 
> > No issues seeing AAAA for Facebook, Netflix, Bing, and others ..
> > 
> > Who at google did you write to? I'm assuming dns-admin.google.com?
> dns-admin@ and google-ipv6@, I think the latter got me the first answer.
> Bernhard

Thanks! I got a response with an explanation.

Although I didn't mention it in my earlier e-mail, we did have a 
fiber cut induced outage to our external IPv6 connectivity for 
many hours on Tuesday, May 29th. I did mention this to dns-admin@
google.com and they confirmed that this long outage skewed their
IPv6 brokenness measurements and put us on the blacklist, and
that it will likely take a couple more days to age out of the list.

The fiber cut prompted us to multihome our external IPv6 connectivity 
two days later to protect us against this. 

So, Google is actively measuring IPv6 connectivity issues and 
dynamically maintaining a AAAA blacklist. Not sure if any of the
others are, so far we seem to be getting AAAA from everyone else.

For now, I'm contemplating turning up another IP address on our 
primary resolver and configuring it to use that for outbound 
queries. But that seems rather drastic.

Shumon Huque
University of Pennsylvania.

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