Re: Ipv6 help

[Mark Andrews <marka () isc org>]

> On 27 Aug 2020, at 15:58, Bjørn Mork <bjorn () mork no> wrote:
>
> Brian Johnson <brian.johnson () netgeek us> writes:
>
> > > 1) It needs *much less* IPv4 addresses (in the NAT64) for the same number of customers.
> >
> > I cannot see how this is even possible. If I use private space
> > internally to the CGN, then the available external space is the same
> > and the internal customers are the same and I can do the same over sub
> > ratio under both circumstance. Tell me how the math is different.
>
> Because NAT64 implies DNS64, which avoids NATing any dual stack service.
> This makes a major difference today.

Only if you don’t have a CLAT installed and for home users that is suicide
at there is too much IPv4 only equipment.

What really pushes traffic to IPv6 is that hosts prefer IPv6 by default.  This
works as long as the clients see a dual stack network.

And no NAT64 does not imply DNS64.  You can publish a ipv4only.arpa zone with
the mappings for the NAT64.  There are now also RA options for publishing these
mappings.  There are also DHCPv6 options.

Mark

> Bjørn

-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742              INTERNET: marka () isc org