In message <f1dedf9c0902041735x4a9cb6f9nc5b5bbf1201a2...@mail.gmail.com>, Scott Howard writes: > On Wed, Feb 4, 2009 at 4:16 PM, Patrick W. Gilmore <patr...@ianai.net>wrote: > > > I guess I was thinking about v4 modems which do not get a subnet, just an > > IP address. If we really are handing out a /64 to each DSL & Cable modem, > > then we may very well be recreating the same problem. > > > v4 just gets a single IP address, which is why we need NAT, and apparently > NAT is evil. > > To some extent the /64 can be though of as "just an IP" from the ISP > perspective (in the same sense that an IPv4 IP is just a /32 "network"), > which has the ability for the CPE to then somehow split it out between > multiple hosts - probably using autoconfig (in the same way with IPv4 it's > "split up" by the port with NAT).
You hand out multiple /64's. As many as the client requests up to a /56 or /48 depending apon which break point you choose. The address space is assigned to ISP's on the presumption that you will be handing out the equivalent of /56's or /48's worth of address space to each customer. > What happens when a customer wants to run multiple networks is something I > haven't seen answered yet - with NAT it's easy, but as I said, NAT is > apparently evil... > > > On Wed, Feb 4, 2009 at 5:20 PM, Matthew Moyle-Croft <m...@internode.com.au>wro > te: > > > but my point was that people are starting to assume that v6 WILL mean > > static allocations for all customers. > > > By design IPv6 should mean _less_ static allocations than IPv4 - in the > event that a client disconnects/reconnects and gets a new /64 then their > network *should* automatically handle that fact, with all clients > automagically renumbering themselves to the new /64, updating DNS, etc. > Local communications won't be impacted as they should be using the > link-local address. > > The bit that isn't clear at the moment is if (and how well) that will > actually work in practice. And that brings us back to the good old catch-22 > of ISPs not supporting IPv6 because consumer CPE doesn't support it, and CPE > not supporting it because ISP don't... > > Scott. -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: mark_andr...@isc.org