On Mon, 9 May 2005, Daniel Roesen wrote:
I do agree that /56s will be enough for almost all customers. But then you will see scenarious that people outgrow the /56 and need a new /48 and renumber AND restructure their network into this new space. THIS is what "/48 for everone" is trying to prevent as much as possible. Reserving a /48 space but only assigning /56 makes no sense either. A /56 is 256 subnets only if ignoring ANY hierarchy. If you accept 2-3 levels of hierachy into the customer network, your efficiency goes down, and 8bits of subnetting starts to smell v4ish again.
I could probably agree to /56 for residential access though. But definately not for non-residential access like non-miniature companies, universities etc.
Do we really gain enough by going down to /56 that is worth the hassle?
IMHO, changing the HD-Ratio is a better idea, with no downside I can currently see (can anyone?).
I agree with Daniel here (wow..:), though I'd prefer to keep our finger out of /48 boundary even for residential use. I guess most people failed to register the statements in the presentation like: "This is a highly speculative exercise." "__If__ this is looking slightly uncomfortable..." etc. If the goal was to allow the more (broadband) ISPs to use the default allocation sizes, using something like /56 might be worth considering. But this doesn't seem to be the goal. It seems to me that beyond a certain point, 1) HD ratio needs to tightened (that is, if you have 10M customers, you shouldn't really need 1000M /48's.), and/or 2) The more is requested, the more the ISPs have to show evidence of their current usage base, i.e., a startup ISP in China couldn't claim 100M customer base in 2 years. -- Pekka Savola "You each name yourselves king, yet the Netcore Oy kingdom bleeds." Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings