On Mon, Jan 25, 2010 at 8:01 PM, Owen DeLong <o...@delong.com> wrote: > > 2^128 is a "very big number." However, from a network engineering > perspective, IPv6 is really only 64bits of network address space. 2^64 > is still a "very big number." > > An end-user assignment /48 is really only 2^16 networks. That's not > very big once you start planning a human-friendly repeatable number > plan. > > An end-user MINIMUM assignment (assignment for a single "site") is > a /48. (with the possible exception of /56s for residential customers > that don't ask for a /48). > I have worked in lots of different enterprises and have yet to see one that > had more than 65,536 networks in a single site. I'm not saying they don't > exist, but, I will say that they are extremely rare. Multiple sites are a > different > issue. There are still enough /48s to issue one per site.
Networks per site isn't the issue. /48s per organization is my concern. Guidelines on assignment size for end-user sites aren't clear. It comes down to the discretion of ARIN. That's why I like pp 106. It takes some of the guess-work/fudge-factor out of assignments. > An ISP allocation is /32, which is only 2^16 /48s. Again, not that big. > > That's just the starting minimum. Many ISPs have already gotten much larger > IPv6 allocations. Understood. Again, the problem for me is medium/large end-user sites that have to justify an assignment to a RIR that doesn't have clear guidelines on multiple /48s. > Once you start planning a practical address plan, IPv6 isn't as big as > everybody keeps saying... > > It's more than big enough for any deployment I've seen so far with plenty > of room to spare. > Owen > -- Tim:> Sent from Brooklyn, NY, United States