IP4 Space - the lie

Cameron Byrne cb.list6 at gmail.com
Fri Mar 5 14:38:02 UTC 2010


On Fri, Mar 5, 2010 at 4:39 AM,  <bmanning at vacation.karoshi.com> wrote:
> On Thu, Mar 04, 2010 at 10:05:43PM -0500, Steve Bertrand wrote:
>> On 2010.03.04 20:55, Owen DeLong wrote:
>> >
>> > I proffer that
>> > such effort is better spent moving towards IPv6 dual stack on your
>> > networks.
>>
>> I *wholeheartedly* agree with Owen's assessment. Even spending time
>> trying to calculate a rebuttal to his numbers is better spent moving
>> toward dual-stack ;)
>>
>> Nice.
>>
>> Steve
>
>
>        er... what part of dual-stack didn't you understand?
>        dual-stack consumes exactly the same number of v4 and v6 addresses.
>
>        if you expect to dual-stack everything - you need to look again.
>        either you are going to need:
>
>        lots more IPv4 space
>
>        stealing ports to mux addresses
>
>        run straight-up native IPv6 - no IPv4 (unless you need to talk to
>        a v4-only host - then use IVI or similar..)
>
>        imho - the path through the woods is an IVI-like solution.

I have a similar perspective.  Your point about dual-stack is spot-on.
 Thats why the future, IMHO, will look like CGN / LSN meaning:
NAT444, NAT64, and DS-lite.  I am very focused on NAT64 since i
believe all the right incentives are in place in that solution for
both service providers and content folks to move to IPv6 as quickly as
possible, while maintaining some level of IPv4 functions.  The major
limitation here is that some old-school and fringe applications are
IPv4-only while the major applications (major web browsers, email
clients, ...).  The IPv6 capable applications have reached the tipping
point where it is now viable to do IPv6-only + NAT64.

There is one of other catch with NAT64 and IPv6-only.  It breaks
communications with IPv4 literals.  Now, you might says that IPv4
literals in URLs are very seldom.... well ... have a look at how
Akamai does a lot of their streaming.  I just hope it does not come to
a show-down where networks move to IPv6-only since IPv4 is a goner and
now Akamai content is not available while IPv6 early adopters like
Google and Limelight laugh all the way to bank.

Hint: Akamai -- stop using IPv4 literals, and and if you can't use
IPv6 then please use FQDNs so you don't break services to your
customers.

IVI is stateless, which means it requires 1 to 1 IPv4 to IPv6 mapping.
 NAT64 allows multiplexing.

>
> --bill
>
>




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