On 17 Sep 2012, at 15:55, Adrian Bool <a...@logic.org.uk> wrote: > > Hi, > > On 17 Sep 2012, at 15:02, Nick Hilliard <n...@foobar.org> 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
