Toward more sensible whitelisting

Phil Benchoff benchoff at
Tue Jun 14 01:36:23 CEST 2011

The really big content providers are pretty hesitant to add sites to their
whitelist (if they even have one).  IPv6 testing primarily depends on
users entering a special IPv6 URL which most people won't bother with
and may not even know about.  I've been thinking there ought to be some
ways to get users with working IPv6 to try the IPv6 version of a site
without causing too much worry to the content providers.

There are several JavaScript tests of IPv6 connectivity.  Why not use one
of them to inform a user he has working IPv6 and offer an easy way to
switch to the IPv6 version of the site?

If you change the way you evaluate the results, you could have a popup tell
the user he has working IPv6 and let him click a button to be forwarded to
the IPv6 web site.  If a user goes to and has working ipv6,
he could be prompted to switch to  The site operator
could choose a popup, automatically forwarded the user, or present a dialog
within the content of the site.  These all alter the user experience a
bit, but they may be within the range of tolerable changes.

Personally, I'm all for adding an AAAA record and fixing the problems that
show up.  There don't seem to be that many and there is always the option
of removing the AAAA record if necessary.  That being said, I think it
is necessary to work with the big content providers and try to find ways
to address the things they are worried about.  I suspect the engineers
working on IPv6 at those big content companies spend more time convincing
others that it is reasonably safe to try a few things than they do actually
fixing IPv6 issues.  Everyone involved in trying to move IPv6 forward
knows there are broken things in all of the selective IPv6 availability
scenarios.  The questions are which are the least broken and what new ones
can we invent to move on?

The people on the content side of the equation need to understand that
the average user isn't going to go out of his way to help them prove that
IPv6 is viable.  The only users that will change their DNS resolver are
the ones who already type the IPv6 URL.  Network operators with eyeballs
are (probably) not going to bake you a cake or get an NIST certification
that they really do IPv6.  You're going to have to pick the least sucky
looking alternative and take some kind of leap.  If nothing else, start
deploying some JavaScript to estimate how well things would work with IPv6
and help the sites with unhappy eyeballs get things working.

I'm really hoping that an analysis of the numbers and experiences from
IPv6 day show that it's really not so bad.


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