I am not a customer of DreamHost, but a number of my friends and associates are. I have discovered a number of their sites have IPv6 addresses, but are not answering over same.
The list of sites I have discovered having this problem at present:
chris-cline.com (first discovered on 10 October 2014)
jellybabiescantrunawaywhenyoubiteofftheirlegs.co.uk (17 Nov 2014)
If there are other sites exhibiting these symptoms, please reply to this post with the URL.
To reproduce the problem:
kjotte@daedalus:~$ curl -Iv6 http://chris-cline.com/
* Hostname was NOT found in DNS cache
* Trying 2607:f298:4:141::c0c:1e7a...
* connect to 2607:f298:4:141::c0c:1e7a port 80 failed: No route to host
* Failed to connect to chris-cline.com port 80: No route to host
* Closing connection 0
curl: (7) Failed to connect to chris-cline.com port 80: No route to host
Back in September I discovered a friend's site (iamduke.com) exhibiting the same symptoms. This problem was resolved with ticket #94748597. Another customer saw this problem and filed tickets 8463 96219357 (9 Nov) 8463 96260240 (10 Nov) to no avail.
It's been over two years since World IPv6 Launch. IPv6 is production now. Having sites unavailable to a significant portion of the Internet for over a month is deplorable. It appears that DreamHost is not monitoring their own infrastructure for these defects. Customers of their customers should not detect these problems before DreamHost. See: http://blog.flyingpenguintech.org/2014/05/monitor-your-ipv6.html
I have gladly recommended DreamHost in the past because of its proactive position on IPv6. I am seriously reconsidering that recommendation.