Except that in the past I've had major issues with Cloudflare's IPv6 service, recently one of the issues was that Centurylink customers (at least in the Denver area) were unable to visit any Cloudflare hosted IPv6 sites.
This meant that until I reported the issue to Cloudflare/StackExchange that people using IPv6 were UNABLE to access those resources needed to load the site (the server would hang indefinitely, so happy eyeballs did not work!). In the case of StackExchange on Centurylink that meant that CSS and other resources did not load, for my site (http://defcne.net/) that meant my site didn't load at all!
I absolutely love Cloudflare, but to me it is inexcusable that there is no monitoring to verify that these issues don't exist. It took me filing a report for them to fix the issue.
Ultimately it came down to this:
"We had recently been experiencing IPv6 routing issues with one of our upstream providers for some of our data centers which may have contributed to the issues you had been seeing. We've since disabled transit for that provider to temporarily work around the issue."
Yet this meant that my site/StackOverflow and countless other sites using Cloudflare were offline (if the customer has IPv6 enabled) for almost a week (first report from customer using CenturyLink, me trying to figure out what is going on, to CloudFlare fixing the issue).
Huh, I'm on CenturyLink ipv6 at home and was having weird issues with a number of sites from early last week onwards, and then early this week it magically cleared up. Guess that was likely it.
https://twitter.com/bertjwregeer/status/470243728473325568
Was my Tweet to Stackoverflow regarding the issue.
Here is the paste of the symptoms seen: http://paste.ofcode.org/XQGqerxCNXwYsHDQMZ3aja
This meant that until I reported the issue to Cloudflare/StackExchange that people using IPv6 were UNABLE to access those resources needed to load the site (the server would hang indefinitely, so happy eyeballs did not work!). In the case of StackExchange on Centurylink that meant that CSS and other resources did not load, for my site (http://defcne.net/) that meant my site didn't load at all!
I absolutely love Cloudflare, but to me it is inexcusable that there is no monitoring to verify that these issues don't exist. It took me filing a report for them to fix the issue.
Ultimately it came down to this:
"We had recently been experiencing IPv6 routing issues with one of our upstream providers for some of our data centers which may have contributed to the issues you had been seeing. We've since disabled transit for that provider to temporarily work around the issue."
Yet this meant that my site/StackOverflow and countless other sites using Cloudflare were offline (if the customer has IPv6 enabled) for almost a week (first report from customer using CenturyLink, me trying to figure out what is going on, to CloudFlare fixing the issue).