On Thu, Dec 28, 2017 at 7:24 PM, Ricky Beam <jfb...@gmail.com> wrote:
> Back to the main theme... artificially cutting the address space in half, > just makes the point even stronger. IPv6 address space is, in fact, half as > big as people think it is, because we've drawn a line at /64 Hi Ricky, Your math is a little off. Drawing the line at /64 doesn't cut the address space in half, it shrinks it by roughly 19 orders of magnitude. There are 10^38 IPv6 addresses but only 10^19 IPv6 /64 LANs. -- and the catastrophic part is people *ARE* wiring that into hardware. > Every example I've seen people bat around about just how big 2^128 is, > ignores the reality of Real World Networking(tm). They ignore > infrastructure. The ignore route table size. They ignore the sparse nature > of hierarchical address assignment. In the "10B people === 10B /48's" > example, that's a dense PI allocation scheme that will lead to a global > routing table approaching 10B routes -- you can't aggregate a random > selection of /48s -- with zero consideration for how those 10B networks > will interconnect. > > The simple truth is, we're doing the exact same thing with IPv6 that we > did with IPv4: "The address space is so mind alteringly large we'll never > use even a fraction of it." *pause* "Umm, wait a minute, we're carving this > turkey up alarmingly fast." Will we use up the entire thing? Of course we > will; it's not, in fact, *infinite*, so we *will* eventually assign all of > it. It's going to happen a lot faster than most people think, as we're so > cavalier with handing out vast amounts of space for which most people will > never use more than (a) one LAN, and (b) a few dozen addresses within that > single LAN. Will it happen in 5, 10, 100 years? The later is a safer bet. > (not that I'll be around to collect) But just like IPv4, some decades down > the road, people will see how stupid our allocation scheme really is, and > begin a new "classless" era for IPv6. The short of it is, we got here > first, so we don't have to give a shit about being efficient or frugal. > Yep. Regards, Bill Herrin -- William Herrin ................ her...@dirtside.com b...@herrin.us Dirtside Systems ......... Web: <http://www.dirtside.com/>
