Yahoo and IPv6

Valdis.Kletnieks at Valdis.Kletnieks at
Mon May 9 16:25:55 UTC 2011

On Mon, 09 May 2011 18:16:20 +0300, Arie Vayner said:
> Actually, I have just noticed a slightly more disturbing thing on the Yahoo
> IPv6 help page...
> I have IPv6 connectivity through a HE tunnel, and I can reach IPv6 services
> (the only issue is that my ISP's DNS is not IPv6 enabled), but I tried to
> run the "Start IPv6 Test" tool at and
> it says:
> "We detected an issue with your IPv6 configuration. On World IPv6 Day, you
> will have issues reaching Yahoo!, as well as your other favorite web sites.

The *really* depressing part is that it says the same thing for me, on a *known*
working IPv6 network.

And then when I retry it a few minutes later, with a tcpdump running, it works.

And then another try says it failed, though tcpdump shows it seems to work.

For what it's worth, the attempted download  file is:

% wget
--2011-05-09 11:44:39--
Resolving 2001:4998:f00d:1fe::2000, 2001:4998:f00d:1fe::2002, 2001:4998:f00d:1fe::2003, ...
Connecting to|2001:4998:f00d:1fe::2000|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: unspecified [image/png]
Saving to: `eye-test.png.1'

    [ <=>                                   ] 2,086       --.-K/s   in 0s      

2011-05-09 11:44:39 (154 MB/s) - `eye-test.png.1' saved [2086]

Looking at the Javascript that drives the test, it appears the *real* problem
is that they set a 3 second timeout on the download - which basically means
that if you have to retransmit either the DNS query or the TCP SYN, you're
dead as far as the test is concerned.
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