I've been having trouble getting to cdn.sstatic.net all day. It's been crippling not to be able to play Stack Exchange!

Chrome's resource panel was showing 'host not found' for cdn.sstatic.net.

I think I've tracked it down to this:

I have IPv6 connectivity and my machine is querying for AAAA records first. Here's how it goes:

[michael@challenger:~]$ host -t ANY cdn.sstatic.net
cdn.sstatic.net is an alias for sstatic.net.cdn.cloudflare.net.

OK, a CNAME, let's follow that:

[michael@challenger:~]$ host -t AAAA sstatic.net.cdn.cloudflare.net
Host sstatic.net.cdn.cloudflare.net not found: 3(NXDOMAIN)

Whoah! That's not good. NXDOMAIN means that domain doesn't exist. That's not right. Let's try a different domain to see what should be happening:

[michael@challenger:~]$ host -t AAAA serverfault.com
serverfault.com has no AAAA record

Not sure what exactly is going on here, but someone needs to fix something.

Could be lame referrals: http://dns.squish.net/traverses/90336bfcff65c12ee97d57f05e0ce2df/detail

  • Last I checked, StackExchange doesn't support IPV6, so they wouldn't have an AAAA record. This question, for instance, is still status-deferred. Also, see here.
    – user206222
    Commented Jun 1, 2013 at 3:35
  • 5
    The problem isn't that no AAAA records exist. The problem is that the CDN DNS servers are returning NXDOMAIN ("the domain doesn't exist"), not "no records of that type".
    – MikeyB
    Commented Jun 1, 2013 at 3:36
  • FWIW, I had a lot of trouble getting files to download from the CDN this morning, but I haven't had any troubles since I got them downloaded.
    – animuson StaffMod
    Commented Jun 1, 2013 at 3:37
  • The same thing happens with a type A query, too. One of CloudFlare's DNS servers is on the fritz. The thing is, IPv4-only people won't notice because the other DNS servers are returning responses. But people with IPv6 (like myself) will have more trouble because of the bad response for the AAAA query. Commented Jun 1, 2013 at 3:44
  • Absolutely a DNS problem.
    – Sinthia V
    Commented Jun 1, 2013 at 3:54
  • 2
    We have been making some changes in this area; I've flagged this up to the perpetr... er, I mean: developer involved Commented Jun 1, 2013 at 5:01
  • 2
    lol It's been crippling not to be able to play Stack Exchange!
    – Pekka
    Commented Jun 1, 2013 at 6:03
  • I hope you meant flogged @Marc
    – Pekka
    Commented Jun 1, 2013 at 6:04
  • @Pekka웃 working remotely, I can only flag, not flog; I need to save up the flogging until I next see the team. Commented Jun 1, 2013 at 6:09
  • 1
    @MarcGravell Developer? It's an ops problem! :) Commented Jun 1, 2013 at 6:09
  • @MichaelHampton - never heard of devops?
    – Oded
    Commented Jun 1, 2013 at 8:05
  • CloudFlare is looking into the issue...unfortunately the lack of IPv6 on many of our teams' ISPs make it difficult to repro and debug. Commented Jun 1, 2013 at 14:23
  • 2
    The only winning move is not to...aww, yeah, okay.
    – tombull89
    Commented Jun 1, 2013 at 14:53
  • 5
    @Oded Heard of devops. Never seen it done right. Commented Jun 1, 2013 at 16:56
  • 1
    @NickCraver: he.net and sixxs.net both offer free IPv6 tunnels, simple to setup and run.
    – user147520
    Commented Jun 1, 2013 at 17:50

1 Answer 1


This was actually an edge case we hit with our CDN. We've enabled IPv6 support on our CDN, which should resolve the issue for the time being. We'll continue to monitor the resolution of these DNS entries for both A and AAAA queries.

  • 1
    Just in case it helps: I'm on IPv6 too, and I did NOT get any problems, from Amsterdam.
    – Arjan
    Commented Jun 4, 2013 at 17:16
  • Learned something new today, but I don't know if it means anything ;-) When I run host -t ANY ... with my own provider, I only get IPv6 addresses (if available). Like host -t ANY sstatic.net.cdn.cloudflare.net only gets me IPv6 addresses. But with Google, I get both IPv4 and IPv6, like host -t ANY sstatic.net.cdn.cloudflare.net The Google output matches the output of NOT using -t ANY with my own provider. Again: it might not mean anything, but who knows ;-) (So far, I was always using -t AAAA to force seeing IPv6.)
    – Arjan
    Commented Aug 11, 2013 at 17:00
  • And though I have no problems, nslookup -type=AAAA cdn.sstatic.net on my Mac shows Non-authoritative answer [...] just fine, but also an EMPTY line after Authoritative answers can be found from:. Same when using Google, nslookup -type=AAAA cdn.sstatic.net (Again, no idea if it implies anything. Using host -t AAAA cdn.sstatic.net does not give me any clue about authoritativeness at all.)
    – Arjan
    Commented Aug 12, 2013 at 15:54
  • I am currently having this problem. I am having to disable IPv6 on my network adapter in order to access stack overflow.
    – Lewray
    Commented Sep 25, 2013 at 10:59
  • 1
    Test test test test Commented Jun 7, 2014 at 23:37

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