In message <f1dedf9c0902041735x4a9cb6f9nc5b5bbf1201a240e@mail.gmail.com>, Scott Howard writes:
On Wed, Feb 4, 2009 at 4:16 PM, Patrick W. Gilmore <patrick@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 <mmc@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_Andrews@isc.org