But in point 2 are you not confusing Dynanic DNS with DHCP?
I wasn't sure if you were referring to the IPv6 address of the router, or hosts with IPv6 addresses on your LAN. In any case, my points still stand. The ISP will delegate and route to your connection a fixed IPv6 prefix (a /64, or in my case, a /48 which allows multiple /64's). The router is then configured with any static IPv6 address that lies within that prefix, but for simplicity and to avoid conflict with other hosts on the LAN, I tend to use the very first address of the delegated prefix. So for example, if my prefix is 2001:A:B:C::/64, I'll set the router to have IPv6 address 2001:A:B:C:: (which is 2001:A:B:C:0:0:0:0).
Hosts on the LAN will then have IPv6 addresses 2001:A:B:C:X:X:X:X where, if using RADVD, the last 64 bits (the X:X:X:X) become predictable as they are based on the MAC address of the client (using EUI-64). See http://waldner.netsons.org/f3-eui64.php
- if I have a prefix of 2001:A:B:C::/64 and my MAC address is 00:01:02:03:04:05, my IPv6 address will always be 2001:A:B:C:201:2FF:FE03:405 (static) if RADVD is auto-configuring my client.
As you can see, you don't really have to worry about changing IP addresses any more, and so don't have to worry about dynamic DNS - you'll always know what clients have what addresses, since there is a direct mapping between MAC address and final IPv6 address. All you have to do is set these addresses up on any domains you have as static AAAA records (make sure your DNS servers support AAAA records, of course, which is the IPv6 version of A records).
I mentioned DHCP (and probably confused you) as there is currently another way of auto-configuring clients with IPv6 addresses - DHCPv6. I've not used this at all, but depending on how that is configured, I would imagine it is very similar to standard DHCP. So, you can either make IPv6 clients on your LAN have the same IPv6 address each time they connect (like RADVD) or, give them a different address each time. If the latter, this then does cause a requirement for Dynamic DNS as such clients will have constantly altering IPv6 addresses. But in this case, why configure the client to have a changing IPv6 address at all? If you are wanting to connect to it in the first place, best to make it static and leave it that way so you'll always know what the address is.
On a final note, the difference between DHCPv6 and RADVD is subtle but important. [RADVD doesn't know about DNS servers, or anything else]*. DHCPv6 does. Because I run standard (IPv4) DHCP on my LAN, all my devices get their DNS and domain settings from this, and the RADVD part is like a 'bolt-on' to configure their IPv6 address. If I was to go completely IPv6 (and remove IPv4), I'd have a problem because I would have the auto-address configuration part of IPv6, but not the rest of the package (eg. clients wouldn't be told what DNS servers to use to resolve stuff etc). This is why I'm sure DHCPv6 will eventually become mainstream, and RADVD rendered redundant in due course.
* - just noticed this isn't entirely true anymore: http://tools.ietf.org/html/rfc6106
- things are moving too fast these days!
Edited by mixt (Sun 15-Jan-12 05:33:03)