How do you do rDNS for IPv6 ?

Sun Dec 5 22:13:59 UTC 2010

I've been pondering IPv6 setups, and I don't understand how IPv6 rDNS
is supposed to work.  It's clear enough how you look up any particular
address, but it's not at all clear to me what you put into an rDNS
zone and how you put it there.

In IPv4 land, it is standard to assign matching forward and reverse
DNS for every live IP, and a fair number of services treat requests
from hosts without rDNS with added scepticism. For consumer networks,
it's often something like 12-34-56-78.adsl.incompetent.net, with the
numbers being the IP address forward or backwards.

So if every customer gets a /64, what do you do?  You can use a
wildcard to give the same rDNS to all 2^64 addresses, but you can't do
matching forward DNS, since a DNS response with 2^64 AAAA records
would be, ah, a little unwieldy.

When hosts self-configure their low 64 bits, do you install a suitable
PTR and AAAA into your DNS?  If so, how?  Do you use DHCPv6 and have it
install the DNS?  Do you do something else?

Signed,
Confused