>I tried to traceroute one of them (Probe #3009) at >2002:568:1047:1:220:4aff:fee0:20ac >and it petered out at 6to4.tyo1.he.net [2001:470:0:17a::2] > >The embedded IPv4 address is 5.104.16.71, which is reachable, >and is indeed the published address of probe #3009, so it does >indeed look like a failure in the return relay path.
Probe 3009 doesn't have a default route on IPv6. I can look at other probes if requested. In the context of 6to4, I'm more curious how users would experience broken 6to4. Happy Eyeballs was supposed to hide broken IPv6 in general and the priority of 6to4 address in destination selection should be below IPv4.
