From: Rick Astley (no email)
Date: Thu Jan 03 2008 - 04:21:18 EST
On Jan 3, 2008 3:52 AM, Rick Astley <> wrote:
>
> >Take someone like Comcast with ~12 million subscribers.
>
> >It would take an IPv6 /24 to get 16.7 million /48's (2^24). With a net
> efficiency of 10% they are going to need to be allocated 120 million /48's.
> It would take a /21 to give them 2^(48-21) = ~134 million /48's.
>
> >So in short, a /48 to subscribers seems like complete overkill, and a /32
> to ISP's seems completely inadequate (80 vs 16 bits).
>
> >I thought one of the goals of IPv6 was to assign ISP's huge blocks with
> low utilization so they don't have push a bunch of individual prefixes out
> to the worlds routing tables?
>
> >It seems to me while being extra super sure we meet goal 1 of making sure
> NAT is gone for ever (and ever) we fail goal 2 of not allocating a bunch of
> prefixes to ISP's that are too small.
>
PS. say for example we would like to meet goal 2 while giving customers
/48's at the same time. We decide a an initial projected utilization of 1%
or .1% is more appropriate for Comcast.
In order to give them 1.2 billion /48's (1% utilization), they would need 2
/18's.
For 12 billion (0.1% utilization), they would need a /14.
In which case the depletion of IPv6 space starts to seem possible.
Your response might be "Why would an ISP need 0.1% utilization?"
My answer: "Why would a customer need 0.000000000000000000000001%utilization?"
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