On 04/01/2013 06:14 PM, SM wrote: >> with IPv6 connectivity. However, it's inappropriate to rely on >> pervasive implementation of Happy Eyeballs as the sole solution to >> prevent end host impacts, since the end user may not know that IPv6 is >> actively being disabled on this network, or that their IPv6 >> implementation is otherwise broken. This is a problem that continues >> to get worse the more dual-stack content becomes available. > > I agree with the last sentence. Happy Eyeballs is about the HTTP. > There are other applications protocols too. :-) Happy eyeballs is about HTTP. But part of the approach predates "Happy Eyeballs" -- please see RFC5461. Signaling hosts when packets are being dropped allows for a more informed decision/reaction on the host-side. Removing the AAAA records when you're not going to allow such connectivity reduces the potential problem (at the end of the day, this is kind of the whitelisting approach that has been applied to the general case by content providers -- with the caveat that in this case you positively know that such connectivity is not present). Thanks, -- Fernando Gont SI6 Networks e-mail: fgont@xxxxxxxxxxxxxxx PGP Fingerprint: 6666 31C6 D484 63B2 8FB1 E3C4 AE25 0D55 1D4E 7492