I'm not sure if there is a meta-bug that this should be attached to, but today I noticed that the current tooling really does not allow to test and debug issues coming from the ipv4/6 transition. Some things that are missing: a) See how the browser resolves the hosts that are part of the website. For which host does it use ipv4 and for which ipv6? b) Force the browser to only use ipv4 / ipv6 to actually test the infrastructure and see if there are holes in it if only one of the two connectivities is available. I'm sure there is lots more, but this would already be a good start.
Good ideas. I don't know of any existing meta-bug.
<rdar://problem/16070885>