IPv6 Addressing Help

Joe Maimon jmaimon at ttec.com
Fri Aug 14 16:43:09 CDT 2009

While I think the address planning problem is serious and hinges 
directly on this issue, I believe all these opinions and stances have 
been repeated so often here and elsewhere that I for one would like to 
hear something new.

To my mind the question is simple.

Decades or Centuries?

trejrco at gmail.com wrote:
> "IIRC, RIPE allocated a /19 to France Telecom. Doesn't take more than a few hundred thousand allocations like that one to wipe out the IPv6 address space."
> Do we expect a few hundred thousand places that need 2^29 (500M, give or take(OTTOMH)) /48s?  Didn't we _just_ get to seeing ~64k ASNs as a limiting factor?
> /TJ
> Sent from my Verizon Wireless BlackBerry
> -----Original Message-----
> From: William Herrin <herrin-nanog at dirtside.com>
> Date: Fri, 14 Aug 2009 16:52:42 
> To: Jeroen Massar<jeroen at unfix.org>
> Cc: Nanog<nanog at nanog.org>
> Subject: Re: IPv6 Addressing Help
> On Fri, Aug 14, 2009 at 2:40 PM, Jeroen Massar<jeroen at unfix.org> wrote:
>> William Herrin wrote:
>> [..]
>>> I'm not aware of any way of dynamically assigning an IPv6 subnet to a
>>> customer that's as well automated as IPv4 /32 dynamic assignment to a
>>> DSL router with an RFC1918 NATed interior, but that may just be my
>>> ignorance since I haven't needed to research it.
>> DHCP-PD (prefix delegation)
> Hi Jeroen,
> Cool. So we'll have $100 CPE which uses it in a relatively idiot-proof
> manner sometime between now and eternity.
>>> Static IP customer: /60
>> ARIN defines a /56 minimum. That is the reason that ISPs get a /32.
>> RIPE defines a /48 at the moment.
> ARIN "defines" a /64 minimum customer assignment and suggests /56.
> They go on to say that, "RIRs/NIRs are not concerned about which
> address size an LIR/ISP actually assigns."
> See ARIN NRPM  https://www.arin.net/policy/nrpm.html#six54
>>> I recommend /60 as the customer default where most folks suggest /56
>>> or /48. The IPv6 use profile looks a heck of a lot like the IPv4 use
>>> profile and /60 is 16 subnets. How many of your customers find a
>>> reason to use more than 3 IPv4 subnets, including their RFC1918 ones?
>>> Relatively few.
>> Think Future. And why bother with that anyway. If you as an ISP needs
>> more address space just ring RIPE/ARIN/APNIC and ask for more, they will
>> happily give it to you.
> The future looks a lot like the past but with more blinking lights.
> Seriously, I'm pretty nuts when it comes to networking. My basement is
> AS11875, multihomed with about 35mbps of bandwidth. If I can't imagine
> how *I* would use more than 16 subnets then it's a safe bet that many
> years will pass before Joe random DSL customer wants to.
> The world won't end, even if you assign every customer a /48. But why
> be so grossly wasteful *before* anyone has demonstrated a practical
> use for doing so?
>> I guess you ran the numbers on how to run out of IPv6 address space?
> IIRC, RIPE allocated a /19 to France Telecom. Doesn't take more than a
> few hundred thousand allocations like that one to wipe out the IPv6
> address space.
> Regards,
> Bill Herrin

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