Nathan Ward <nanog@daork.net> wrote:
The other mode would be to set up mail.ipv6.yahoo.com and have customers use that for whatever protocol they send/receive mail with, and not point an MX at an AAAA for the time being.
Actually I would do it the other way around, adding AAAA to the MX set is rather painless, as only full-blown MTAs with well-defined fallback procedures (and without a user sitting in front of it wondering why the hell it is so slow) use it anyway. Traffic won't be high, I think you won't need an LB from day 0, one server should be sufficient for current traffic (and if not, you can always add multiple AAAA records). Enabling IPv6 on customer-facing services is harder, as you will almost certainly run into some broken client. A dedicated hostname for tests is good, but that won't help you find the people that are completely unaware of the existence of IP at all, but somehow got a broken IPv6 stack installed (old Linux kernels with on-link assumption for example). Regards, Bernhard