Dual stack IPv6 for IPv4 depletion
Owen DeLong
owen at delong.com
Thu Jul 9 01:32:13 UTC 2015
Only if you are trying to prevent IPv6 from reaching its full potential.
Owen
> On Jul 8, 2015, at 17:57 , Mike Hammett <nanog at ics-il.net> wrote:
>
> Isn't /56 the standard end-user allocation?
>
>
>
>
> -----
> Mike Hammett
> Intelligent Computing Solutions
> http://www.ics-il.com
>
>
>
> Midwest Internet Exchange
> http://www.midwest-ix.com
>
>
> ----- Original Message -----
>
> From: "Israel G. Lugo" <israel.lugo at lugosys.com>
> To: "Mark Andrews" <marka at isc.org>
> Cc: "NANOG" <nanog at nanog.org>
> Sent: Wednesday, July 8, 2015 7:45:50 PM
> Subject: Re: Dual stack IPv6 for IPv4 depletion
>
>
> On 07/09/2015 12:59 AM, Mark Andrews wrote:
>> In message <559DB604.8060901 at lugosys.com>, "Israel G. Lugo" writes:
>>> Doesn't seem to make sense at all for the ISP side, though. Standard
>>> allocation /32. Giving out /48s. Even if we leave out proper subnet
>>> organization and allocate fully densely, that's at most 65,536 subnets.
>>> Not a very large ISP.
>> /32 is not the standard allocation. It is the *minimum* allocation
>> for a ISP. ISPs are expected to ask for *more* addresses to meet their
>> actual requirements.
>
> Thank you for pointing that out. When speaking of /32 I was referring
> specifically to RIPE policy, with which I am more familiar: "Initial
> allocation size" for a LIR is /32, extensive to a /29 with minimal
> bureaucracy. Perhaps I should have said "default allocation".
>
> I understand ISPs should ask for more addresses; however, even e.g. a
> /24 (8x /32) seems to me like it could be "roomier".
>
>
>>> People usually look at IPv6 and focus on the vast numbers of individual
>>> addresses. Naysayers usually get shot down with some quote mentioning
>>> the number of atoms in the universe or some such. Personally, I think
>>> that's a red herring; the real problem is subnets. At this rate I
>>> believe subnets will become the scarce resource sooner or later.
>> No. People look at /48's for sites. 35,184,372,088,832 /48 sites out of the
>> 1/8th of the total IPv6 space currently in use. That is 35 trillion sites
>> and if we use that up we can look at using a different default size in the
>> next 1/8th.
> Yes, if we look at end sites individually. My hypothesis is that these
> astronomic numbers are in fact misleading. There isn't, after all, one
> single ISP-Of-The-World, with The-One-Big-Router.
>
> We must divide the addresses by ISPs/LIRs, and so on. Several bits in
> the prefix must be used for subaddressing. A larger ISP will probably
> want to further subdivide its addressing by region, and so on. With
> subdivisions comes "waste". Which is something we don't need to worry
> about at the LAN level, but it would be nice to have that level of
> comfort at the subaddressing level as well.
>
> Let's say I'm a national ISP, using 2001:db8::/32. I divide it like so:
>
> - I reserve 1 bit for future allocation schemes, leaving me a /33;
> - 2 bits for network type (infrastructure, residential, business, LTE): /35
> - 3 bits for geographic region, state, whatever: /38
> - 5 bits for PoP, or city: /43
>
> This leaves me 5 bits for end sites: no joy.
>
> Granted, this is just a silly example, and I don't have to divide my
> address space like this. In fact, I really can't, unless I want to have
> more than 32 customers per city. But I don't think it's a very
> far-fetched example.
>
> Perhaps I'm missing something obvious here, but it seems to me that it
> would've been nice to have these kinds of possibilities, and more. It
> seems counterintuitive, especially given the "IPv6 way of thinking"
> which is normally encouraged: "stop counting beans, this isn't IPv4".
>
> Regards,
> Israel G. Lugo
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