While migrating from ipv4 to ipv6, there are going to be a lot of servers with AAAA/A6 records in the DNS, but either no actual ipv6 connectivity (not interconnected networks), or some services not listening for ipv6 (it'll take quite some time before all server applications are fixed to do ipv6). If the connection attempt using ipv6 fails (connection refused or timed out or whatever), I think the networking component should mark the service or address unreachable using ipv6 and retry using ipv4 instead. Currently I need to use an IPv4 proxy to disable IPv6 in the browser and reach my IPv4-only web server since apache was untrivial to patch to do IPv6 with all the modules I use.

This is a dupe of bug 86917. (see also the dupe bug 66872) *** This bug has been marked as a duplicate of 86917 ***

VERIFIED: same problem. marked the original bug mostfreq.