Another v6 question

Owen DeLong owen at
Tue Jan 25 15:15:35 CST 2011

On Jan 25, 2011, at 12:03 PM, bmanning at wrote:

>>> Second, as I was crunching a few numbers to get a rough estimate of what a
>>> global table would look like in say 3 or 5 years after v4 is exhausted (I
>>> understand that it's completely unpredictable to do this, but curiosity
>>> killed the cat I guess), and in a few cases, I stopped due to the shear size
>>> of the amount of prefixes I was coming with. Where i'm getting with this is
>>> has anyone done any crunching on prefix count for v6 (as in estimates of
>>> global table usage with the various prefix lengths seen above _based_ on the
>>> initial allocation of the v6 space (not the entire v6 space itself)). I'm
>> You really can't map prefix availability to prefix usage.
> 	this is so true. and yet you proceed, in your next few sentences
> 	to do -exactly- that. :)
Not really...

>> There are 4 billion IPv4 /32s. There aren't 4 billion LIRs that will get /32s.
> 	presuming the LIR model holds...

>> There are 256 trillion IPv4 /48s (roughly). There are not 256 trillion
>> end sites that will apply for /48s.
> 	apply to whom? the RIR/LIR model is not the only place/venue
> 	for getting a /48.
To whomever they are getting their addresses from. It's irrelevant to
the purposes of the discussion. The point was to show the total
amount of supply vastly exceeds any rational perception of demand.

>> The whole point of IPv6 is that the number of prefixes vastly exceeds
>> the number of applicants that will use them.
> 	not sure I buy that arguement.  
OK, maybe not the whole point, but, certainly the primary reason
for widespread IPv6 adoption is going to be to eliminate the shortage
of IP addresses present in IPv4.

>> To measure the likely content of the IPv6 global table, then, we need
>> to look at the number and type of users rather than looking at the
>> maximum available number of prefixes.
> 	if there is a global table that is interesting (debatable point)
> 	then I'd be more interested in curn rates and overlapping announcements.
Whatever. The point is that to predict the likely size of such a table,
presuming it continues to exist, one must consider the size and
type of prefixes that will be in it rather than considering the maximum
possible size based on available prefixes.


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