On Fri, 2010-02-12 at 11:23 +0000, Us wrote:
Well, personaly as being the first commecial ipv6 provider in our country I had the same reservations. But after a talk with our IPv6 experts (go6.si) I/we just accepted the fact that we're wasting perfectly good address space and we just put /64 on P2P links...
Even though others have said that the argument of wasting space isn't useful and that the number of 64s is near infinite, I wanted to show just how :) If you've heard it before, stop reading this mail now. We're using an 1/8th of the IPv6 space this first attempt to do it, or 2001::/3. There are maybe 5 more usable eights in case we screw this up. If some ~9 billion people on this planet *each* used say 16x /64 links, the total usage for this would only amount to a /27, or a 1/2^24th of the 2001::/3 space. A whopping 6 micro-percents, or 0.000006%. 64:s are built to be unique per broadcast domain. In the technologies I am aware of today (which arguably are few), none creates a "broadcast domain scaling problem" by for example connecting each user to every other user on always unique broadcast domains -- THIS would not scale! So the "address space waste" argument for todays network models is void, but there might very well, as Pekka exemplifies, be other technical/engineering constraints that come in to play. Regards, -- Martin Millnert <millnert@csbnet.se>