> On Oct 10, 2023, at 17:20, Mark Andrews <[email protected]> wrote:
>
>
>
>> On 11 Oct 2023, at 09:43, Delong.com via NANOG <[email protected]> wrote:
>>
>>> As a community, we have failed, because we never acknowledged and addressed
>>> the need for backward compatibility between IPv6 and IPv4, and instead
>>> counted on magic handwaving about tipping points and transition dates where
>>> suddenly there would be "enough" IPv6-connected resources that new networks
>>> wouldn't *need* IPv4 address space any more.
>>
>> I’m not sure that we never acknowledged it, but we did fail to address it,
>> largely because I think we basically determined that it’s “too hard”.
>
> It’s not actually that hard to do on a small scale, i.e. inside a home CPE
> with a DNS server and a NAT64 implementation that supports semi static
> mappings. It does require IPv4 sites have IPv6 connectivity. You stand up a
> DNS46 which requests an unused IPv4 address from a prefix block, say 10/8,
> when there is an IPv6 address without an IPv4 address from the NAT64 with the
> IPv6 address it needs to be mapped to with an initial NAT64 lifetime value.
> The DNS46 would forget the mapping after half that initial lifetime. The
> DNS46 would return A records limited half the lifetime or less so they
> timeout before the NAT64 mapping expires. The hard part is scaling up to a
> large client base because not every DNS query results in IP traffic and you
> need a prefix block big enough to support the add rate of the client base.
> Doing this at ISP scale would be interesting to say the least. This is not
> theoretical. It has been implemented in the past though some to the details
> might differ.
That’s not what we’re talking about… That’s translation, not backwards
compatibility.
> Companies that have gone IPv6-only internally do this with fully static IPv4
> to IPv6 mappings and skip the DNS46 step.
But doing that requires that the companies have a certain amount of V4. The
question was how to talk to v4-only hosts with ZERO IPv4 addresses available to
you.
> So if you have a legacy device that can’t talk IPv6 there is a solution space
> that allows it to talk to the IPv6 internet. You need to install it however.
> Adding DNS46 to a nameserver is about a days if you already have a DNS64
> model. The hard bit is working out how to talk to the NAT64 implementation.
> A good project to put on a Raspberry Pi or similar.
I’m a new entity. I need to talk to the IPv4 internet. I have zero IPv4
addresses and none are available to me.
How do I make any of this work?
That’s the question that remains unsolved and that’s the one we most
desperately failed to tackle.
Owen
