Only 5x IPv4 /8 remaining at IANA

Thu Oct 21 17:25:21 UTC 2010

On Thu, Oct 21, 2010 at 8:07 AM, Ben Butler <ben.butler at c2internet.net> wrote:
> Hi,
>
> Showing my ignorance here, but this is one of the things I have wondered, given that we run both v4 and v6 for a period of time on the Internet, presumably at one time or another a particular resource may only be able in v4 land, then v4 and v6, then finally v6 only.
>
> I have never been particularly clear how an end network that exists only in v4 or v6 address space is able to access a resource that only exists in the other.  Is can sort of see some freaking huge NAT box type thing that summarizes v6 in a v4 address scope or contains the v4 address range at some point inside the v6 address space - but how can a v4 host get to a hot in v6 world that sits outside this without going through some form of proxy / nat gateway between the two.
>
> Or are the two simply not inter-communicable?
>
> Ben
>
> -----Original Message-----
> From: Patrick Giagnocavo [mailto:patrick at zill.net]
> Sent: 21 October 2010 15:59
> To: Owen DeLong; NANOG
> Subject: Re: Only 5x IPv4 /8 remaining at IANA
>
> On 10/21/2010 4:28 AM, Owen DeLong wrote:
>
>>> Actually for those of my clients in one location, it served as an
>>> impetus to extend a contract with Level3 for another 3 years - with
>>> their existing allocation of a /24 of IPv4 addresses included.
>>
>> All well and good until some of their customers are on IPv6...
>> Then what?
>
> I'm sorry, can you expand on exactly what you mean by this?
>
> Are IPv6 connected machines unable to access IPv4 addresses?

IPv6->IPv4 is called NAT64, and it works today pretty well. Most
things work very well (web, email, ...), somethings don't (skype ..)

http://www.youtube.com/watch?v=AmjlptEva4Y#t=1h32m26s
http://tools.ietf.org/html/draft-ietf-behave-v6v4-xlate-stateful-12
http://ecdysis.viagenie.ca/

As your major NAT vendor, they probably have NAT64 in the road map for
the next 6 to 12 months.

IPv4->IPv6 initiated connection are a lost cause that cannot scale in
any good way.

Cameron