Hi, On Thu, May 19, 2016 at 10:19:07AM +0200, Mikael Abrahamsson wrote:
My opinion is that anything between /56 and /48 is fine. As far as I know, current RIPE policy gives the ISP the option to without motivation, ask for enough IPv6 addresses to offer each customer a /48 and I'd like to keep it that way.
Right. The reason why the address policy isn't fixed at "customer = /48" anymore is because Geoff Huston did some math, "back then", and came to the conclusion that IPv6 might actually be not sufficiently large if - every residential customer receives one or more /48s (multiple ISPs) - RIR->LIR policy has very liberal HD ratio (so for large blocks you get 1:10000 or worse utilization ration) - every human on earth gets access to the Internet so the policy was changed to make this a local decision, and sort of recommend a /56 (but /48 is OK, and counted as "256 customers with /56" when judging utilization) (and tightened HD ratio somewhat). With-no-hats, I think a /56 for residential is good enough, especially with homenet coming to replace the old DHCP-PD hierarchical model where you could end up with prefix shortage if you have router cascades, due to protocol inflexibility ("/56 router delegating /60 -> delegating /64 and then?"). With homenet, 250 subnets in the home would "just work" given a /56, and I'm too narrow-minded to imagine deployments that need more *subnets*. Gert Doering -- APWG chair -- have you enabled IPv6 on something today...? SpaceNet AG Vorstand: Sebastian v. Bomhard Joseph-Dollinger-Bogen 14 Aufsichtsratsvors.: A. Grundner-Culemann D-80807 Muenchen HRB: 136055 (AG Muenchen) Tel: +49 (0)89/32356-444 USt-IdNr.: DE813185279