IP4 Space - the lie

Dan White dwhite at olp.net
Sat Mar 6 16:14:37 UTC 2010


On 06/03/10 23:36 +1030, Mark Newton wrote:
>
>On 06/03/2010, at 1:10 AM, Dan White wrote:
>
>> On 05/03/10 12:39 +0000, bmanning at vacation.karoshi.com wrote:
>>>> 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.
>> 
>> I would expect the number of v6 addresses assigned to a host to be a
>> multiple of the number of v4 addresses, depending on the type of host.
>
>That's because you haven't done it yet.  When you start doing it,
>you'll see that the number of v6 addresses assigned to a host will
>bear almost no relationship whatsoever to any metrics you've previously
>used to allocated IPv4 addresses.

I have. Windows XP, for instance, will auto assign multiple addresses
during auto configuration, including random identifiers.

If you through in multiple routers for redundancy, then you start to have a
multiplying effect, compared to your typical one v4 address per end user
host.

Also, the number of publicly routeable v6 addresses assigned to hosts is
surely much higher, on average, than the public v4 addresses assigned
to those hosts.

>> Or, dual stack today. When you've run out of IPv4 addresses for new end
>> users, set them up an IPv6 HTTP proxy, SMTP relay and DNS resolver and/or
>> charge a premium for IPv4 addresses when you start to sweat.
>
>I expect that once we all work out that we can use SP-NAT to turn "dynamic
>IPv4 addresses" into "shared dynamic IPv4 addresses," we'll have enough
>spare IPv4 addresses for much of the foreseeable future.
>
>If I have half a million residential subscribers and I can get ten 
>subscribers onto each NATted IPv4 addresses, then I only need 50,000
>addresses to service them.  Yet I have half a million addresses
>*right now*, which I won't be giving back to my RIR.  So that turns
>into 450,000 saleable addresses for premium customers after the
>SP-NAT box is turned on, right?

Possibly. I understand how to do HTTP proxies today, and understand its
limitations. But it's a far more appealing technology than all these future
technologies being proposed that fit in the 'once we all work out that we
can use' category.

-- 
Dan White




More information about the NANOG mailing list