> [snip... I hate slash, I hate android, blah balh] > > 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 -- and the > catastrophic part is people *ARE*
Incorrect... If you want to make that argument, that we shouldn’t have SLAAC and we should use /96 prefixes, that wouldn’t double the space, it would multiply it by roughly 4 billion. However, I have to wonder why you think we will burn through 18 quintillion /64s, even with the current scheme? Put another way, that’s roughly 281 trillion /48 end sites. > 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. Most of the time, I use the 10B people = 200B /48s, or less than 1/1000th of the total address space. (2.5x for sparse and infrastructure and 8x for provider free pools). The routing problem might be real if everyone goes to PI, but I think that’s an unlikely scenario. > > 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. Your definition of “amazingly fast is pretty odd... we’ve allocated tiny fractions of 2 /3 prefixes to special uses (multicast, ULA, loopback, unknown, etc.). Beyond that, there’s a /3 delegated to IANA as unicast space for distribution to the RIRs. Of that /3, IANA has delegated a little more than 5 /12s to RIRs. That’s the total of 20 years worth of turkey carving and constitutes well under 1/8th of the address space. Issued. By that measure, we’ve got well over 160 years to worry about runout. I’m not saying we won’t ever run out, but I am saying that nobody alive today is likely to see it. Owen
