The "minimum" network size for IPv4 is a /29 The "Minimum" network size for IPv6 is a /64
That means that IPv6 has 2**(64-29) more minimal sized networks that IPv4 (the fact that the size of those networks is different is immaterial). 2**(64-29) is 34,359,738,368 or 3.4e10 That is quite a few more networks. Even the currently allocated space contains 2,147,483,648 times the number of "minimum sized networks" as IPv4. --- The fact that there's a Highway to Hell but only a Stairway to Heaven says a lot about anticipated traffic volume. >-----Original Message----- >From: NANOG [mailto:nanog-boun...@nanog.org] On Behalf Of Mel Beckman >Sent: Wednesday, 20 December, 2017 14:39 >To: William Herrin >Cc: nanog@nanog.org >Subject: Re: Waste will kill ipv6 too > >Bill, > >You are correct. > >As a double check, I divided 340282366920938463463374607431768211456 >by 4294967296, getting >79228162514264<tel:79%20228%20162%20514%20264>337593543950336<tel:337 >%20593%20543%20950%20336>, which is 28.8 orders of magnitude :) > > -mel > >On Dec 20, 2017, at 12:58 PM, William Herrin ><b...@herrin.us<mailto:b...@herrin.us>> wrote: > >On Wed, Dec 20, 2017 at 1:48 PM, Mel Beckman ><m...@beckman.org<mailto:m...@beckman.org>> wrote: >I won’t do the math for you, but you’re circumcising the mosquito >here. We didn’t just increase our usable space by 2 orders of >magnitude. It’s increased more than 35 orders of magnitude. > >Hi Mel, > >The gain is just shy of 29 orders of magnitude. 2^128 / 2^32 = >7.9*10^28. > >There are 2^128 = 3.4*10^38 IPv6 addresses, but that isn't 38 "orders >of magnitude." Orders of magnitude describes a difference between one >thing and another, in this case the IPv4 and IPv6 address spaces. > > >Using a /64 for P2P links is no problem, really. Worrying about that >is like a scuba diver worrying about how many air molecules are >surrounding the boat on the way out to sea. > >It's not a problem, exactly, but it cuts the gain vs. IPv4 from ~29 >orders of magnitude to just 9 orders of magnitude. Your link which >needed at most 2 bits of IPv4 address space now consumes 64 bits of >IPv6 address space. > >Then we do /48s from which the /64s are assigned and we lose another >3 or so orders of magnitude... Sparsely allocate those /48s for >another order of magnitude. From sparsely allocated ISP blocks for >another order of magnitude. It slips away faster than you might >think. > >Regards, >Bill Herrin > > >-- >William Herrin ................ >her...@dirtside.com<mailto:her...@dirtside.com> >b...@herrin.us<mailto:b...@herrin.us> >Dirtside Systems ......... Web: <http://www.dirtside.com/>
