* [email protected] (Thomas Schäfer) [Sat 14 Jun 2014, 18:50 CEST]:
thomas@diener:~> host www.xbox.com
[...]
thomas@diener:~> ping6 www.xbox.com
unknown host
thomas@diener
But sometimes it works.
Is it an resolver-problem, or is the network not stable, or is it PEBKAC?
This is a problem with Microsoft's loadbalancing nameserver
implementation, it seems. They return CNAME when asked for A but no
CNAME when asked for AAAA.
The chain is as follows:
www.xbox.com -> ns[1-6].msft.net say CNAME for www.gtm.xbox.com ->
ns*-*.gtm.xbox.com respond with empty in case of AAAA and CNAME
wildcard.xbox.com-c.edgekey.net when queried for A.
You see this working sometimes because if you asked first for A then
your resolver will know the CNAME and while the TTL of 30 seconds
hasn't yet expired it will know where to ask for AAAA records (Akamai).
Can anybody confirm this problem, or suggest a better test?
Talk to Microsoft, their GLSB code is out of spec. And it will break
visiting xbox.com for all dual-stacked hosts, and for everybody else
in the next 300 seconds, if the cache was empty!
I'm Cc'ing Mehmet who knows something (heh) about DNS and is with
Microsoft.
-- Niels.
--
"It's amazing what people will do to get their name on the internet,
which is odd, because all you really need is a Blogspot account."
-- roy edroso, alicublog.blogspot.com
