[Kea-users] Getting Started: Dual-stack Dynamic DNS Updates

[Dan Oachs]

I can't answer most of your questions, but I can tell you that the
fd75:81b2:5386:4f06::/64 subnet is part of the Unique Local Address ( ULA
<https://en.wikipedia.org/wiki/Unique_local_address> ) range for IPv6.  And
you are correct, that is somewhat akin to rfc1918 space.  They should only
be getting an address in that range if your router or DHCPv6 server is
telling them to.

--Dan


On Fri, Mar 3, 2023 at 3:23 PM Troy Telford <ttelford.groups at gmail.com>
wrote:

> I’ve been successful so far in getting Kea to serve IPv4 with both forward
> & reverse dynamic DNS. Thus far I’ve only used SLAAC and static zone files
> for IPv6 in DNS in my test/educational network. (A small network, so I can
> learn & experiment).
>
> I’ve had a notion of also learning DHCPv6 so I know how it works. (I’ve a
> goal to understand and have dual stack DHCP with forward/reverse DNS
> updates).
>
> It’s already clear it’s different from IPv4 DHCP. I’ve been able to piece
> together a rough idea of some basics - enough that there are signs of life:
> I configured `radvd` with the correct flags so macOS & iOS use DHCPv6, for
> example. it seems many of the hosts are getting IPv6 addresses from
> Kea-dhcp6, though it’s equally clear I’m missing important details, as
> things aren’t working as I’d thought:
>
> In this dual-stack environment, it seems kea-dhcp-ddns is sort of all over
> the place: I’m seeing either IPv4 updates, or IPv6 updates, but not both in
> DNS.
>
> I want to make sure I understand the situation properly before getting
> lost in the weeds (ie. Trying to ‘fix’ the wrong thing):
>
>    * Is it true that in a dual-stack environment, it’s necessary for the
> _client_ to be configured properly in order for `kea-dhcp-ddns` to be able
> to update the DNS server properly?
>        * I’ve read that both v4 and v6 clients need to send the same DUID
> for ddns to work properly - is that correct?
>        * Am I wrong that most Linux distributions, and macOS aren’t
> configured this way by default? (I haven’t checked Windows yet…)
>        * I’m sure there are minutae I need to learn - any hints?
>    * While I don’t _think_ I’m running into any unimplemented
> functionality, is there something I should be aware of for the simple goal
> of dual-stack forward/reverse dynamic DNS? - (I’m using kea-2.2.0 on Debian
> Sid because I’ve apparently 'lived dangerously' for 25 years.)
>
> I’ve also noticed that many hosts are getting “new” IPv6 addresses that
> are from a subnet that’s not link-local (I think), and _not_ the subnet
> that I’m assigning via DHCPv6: fd75:81b2:5386:4f06::/64.
>
> * I think it’s something akin to the 169.254 IPv4 address range, but my
> Google-fu fails me; is there anything special about such a subnet? Why
> would the interfaces be getting such an address?
>
> Thank you.
> --
> ISC funds the development of this software with paid support
> subscriptions. Contact us at https://www.isc.org/contact/ for more
> information.
>
> To unsubscribe visit https://lists.isc.org/mailman/listinfo/kea-users.
>
> Kea-users mailing list
> Kea-users at lists.isc.org
> https://lists.isc.org/mailman/listinfo/kea-users
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.isc.org/pipermail/kea-users/attachments/20230303/2e63fa10/attachment.htm>