On Tue, 30 Nov 2004, Owen DeLong wrote:
[snip a bunch of stuff where we finally appear to basically agree or at least understand each other]
Actually, that fragmentation was primarily the result of being insufficiently stingy early on.
There are many kinds of fragmentation. When you only get (e.g.,) a v4 /24 for a start, and when you need more, you'll have to get a new non-adjacent /24, there's going to be fragmentation.
I don't think you can equate v4 /24 allocation to v6 /48 allocation. A /48 gives an organization 65,536 unique subnets, each of which can accomodate enough hosts that _EVERY_ IPv4 possible host can have 4+billion addresses.
I was not referring to /48's -- that's sufficient for end-sites. I was referring to giving less than /32 or the like for ISPs, and _that_ causing fragmentation of advertisements because the _ISPs_ would have multiple prefixes. There is no need to be unusually stingy about the prefix lengths given to the ISPs.
It's not as we are carving out v4 /8's (1/256 of space) for early adopters. Or even /16's. More like the equivalent space of a host address. That's hardly too much. In fact, it's way too little for those ISPs which have home customers like DSL, and it's going to be a a pain because they either must get a new prefix or give their customers a /64 instead of /48.
I think that if an ISP can show that they have more than 65536 home DSL customers, they will not have a problem getting a /31 or larger as needed. However, I think that today, the bulk of DSL ISPs doe not have that many customers and aren't likely to in the near future.
Uhh, I'd say there are a thousand or two such ISPs in the world. That's not insignificant. It isn't useful to be stingy when allocating prefixes to ISPs which _might_ end up needing more than a /32 for their customer /48 assignments. And if such ISPs decide that rather than going through the process of justifying more space, they end up giving the customers /64's instead.. well, the result might not be pretty. -- Pekka Savola "You each name yourselves king, yet the Netcore Oy kingdom bleeds." Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings