On Sep 17, 2012, at 08:16 , Mark Blackman <[email protected]> wrote:
> > On 17 Sep 2012, at 15:55, Adrian Bool <[email protected]> wrote: > >> >> Hi, >> >> On 17 Sep 2012, at 15:02, Nick Hilliard <[email protected]> wrote: >>> On 17/09/2012 14:37, Adrian Bool wrote: >>>> It seems a tad unfair that the bottom 80 bits are squandered away with a >>>> utilisation rate of something closely approximating zero >>> >>> You are thinking in ipv4 mode. In ipv6 mode, the consideration is not how >> >>> many hosts you have, but how many subnets you are dealing with. Instead of >>> thinking of 128 bits of addressing space, we talk about 64 bits of subnet >>> space. So your statement comes down to: "it seems a tad unfair that the >>> bottom 16 bits are squandered away". This is a more difficult argument to >>> make. >> >> I don't really agree with the "IPv6 think" concept - but let's put that >> aside for now... >> >> The default allocation size from an RIR* to an LIR is a /32. For an LIR >> providing /48 site allocations to their customers, they therefore have >> 16-bits of address space available to them to address their customers. >> >> So, even in "IPv6 think", homes that typically have one subnet have an equal >> number of bits to address their single subnet as an LIR has to address all >> of their customers. >> >> It seems illogical to me that we've got an 128-bit address space, featuring >> numbers far larger than any human can comprehend, yet the default allocation >> to an LIR allows them to address such a feeble number as 65,536 customers - >> a number far smaller than the number of customers for medium to large ISPs. >> >> The default LIR allocation should be a several orders of magnitude greater >> than the typical customer base - not a smaller default allocation. > > Amen, brother! I was doing that particular computation about six months ago > when we had > our first request and arrived at the same conclusion. I've concluded that /48 > for businesses > and /56 for residential sites is the more reasonable approach until we start > getting /24 IPv6 > allocations for LIRs and I think many others have concluded the same. > > - Mark > LIRs which need /24s can get /24s. /32 was never a maximum, it was merely the minimum and as such is a reasonable starting point. The vast majority of ISPs in operation today can give all their customers /48s out of a /28 and still have lots of room to spare. For larger providers, they should have no trouble justifying a much larger block. I know from experience that it is possible to get /24s in the ARIN region with reasonable justification, for example. Owen
