/56 even seems a bit excessive for a residential user, but *shrugs*
----- Mike Hammett Intelligent Computing Solutions http://www.ics-il.com Midwest Internet Exchange http://www.midwest-ix.com ----- Original Message ----- From: "Mel Beckman" <m...@beckman.org> To: "Mike Hammett" <na...@ics-il.net> Cc: "NANOG" <nanog@nanog.org> Sent: Wednesday, July 8, 2015 8:11:05 PM Subject: Re: Dual stack IPv6 for IPv4 depletion Yes. The v6 allocation standards are simple, but can alarming to old-schoolers who have not really thought through the math. A customer gets a /56, which gives them 256 /64 subnets for their own internal use. That accommodates all except the largest customers, and those have the option of getting a /32, which gives them 4.2 billion /64s. ISPs each get a /32 by default, which supports 16.7 million /56 customers. And, of course, the /32 ISP allocation accommodates 4.2 billion ISPs. I don't see the fear. These are just integers, after all. Nothing is really "going to waste". -mel beckman > On Jul 8, 2015, at 5:58 PM, Mike Hammett <na...@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.l...@lugosys.com> > To: "Mark Andrews" <ma...@isc.org> > Cc: "NANOG" <nanog@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 <559db604.8060...@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 >
