BBC News - 'Fresh proposals' planned over cyber-monitoring

[Ben Laurie]

On 11 May 2013 17:26, Roland Perry <lists at internetpolicyagency.com> wrote:
> In article <EADEBDCB-9FBA-4EAA-ADC8-444B93CAD478 at batten.eu.org>, Ian Batten
> <igb at batten.eu.org> writes
>
>>> Basically, the people who specified IPv6 screwed up, big time, in not
>>> making it backwards compatible. They've got all sorts of excuses, that
>>> only geeks who understand products, but not product management, would
>>> relate to.
>>
>>
>> It would be interesting to understand what such a protocol would look
>> like.  The basic problem surely is that if you have two address spaces,
>> one larger than the other, you can't have a 1:1 mapping between the two
>> (and to do so would defeat the object of making the address space
>> larger).
>
>
> All that was necessary was making the bottom 0.1% (or whatever) of IPv6 map
> onto the old IPv4 space.

Oh yeah? So how would an IPv4 machine address the remaining space?