Using IPv6 with prefixes shorter than a /64 on a LAN

Owen DeLong owen at
Tue Jan 25 17:26:29 CST 2011

On Jan 25, 2011, at 2:32 PM, Valdis.Kletnieks at wrote:

> On Tue, 25 Jan 2011 14:21:12 PST, Leo Bicknell said:
>> If you were allocating individual /48's, perhaps.  But see, I'm a
>> cable company, and I want a /48 per customer, and I have a couple
>> of hundred thousand per pop, so I need  a /30 per pop.  Oh, and I
>> have a few hundred pops, and I need to be able to aggreate regionally,
>> so I need a /24.
>> By my calculations I just used 16M /48's and I did it in about 60
>> seconds to write a paragraph.  That's about 279,620 per second, so
>> I'm well above your rate.
> Fine.  You got ARIN or somebody to allocate your *first* /24 in under a minute.
> Now how long will it take you to actually *deploy* that many destinations? And
> where do you plan to get your customers for the next 4 or 5 /24's, and how long
> will *those* deploys take?
> Face it Leo, you can't *sustain* that growth rate.
>> building in a lot of aggregation.  Remember the very first IPv6
>> addressing proposals had a fully structured address space and only
>> 4096 ISP's at the top of the chain!
> How many Tier-1's are there now, even if you include all the wannabes?
> And how long would it take at current growth rates of Tier-1 status to run
> out the *other* 4,087 entries?

RIRs allocate to lots of non-Tier-1 organizations, so, that count is pretty
meaningless no matter what definition of "tier 1" you decide to use.

I suspect that there are probably somewhere between 30,000
and 120,000 ISPs world wide that are likely to end up with a /32
or shorter prefix.


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