Eric - Fred has the model right. The CPE router (actually a gateway with router/firewall/DHCP/DNS services) uses DHCPv6 PD (prefix delegation; RFC 3633) to obtain a prefix (either a /64 or shorter) and then assigns /64 prefixes to any downstream links. The devices in the home use either autonomous address selection or DHCPv6 for address assignment and DHCPv6 for other configuration information. Those devices use DDNS - either in the gateway or provided by the ISP - to announce any publicly accessible addresses.
The net effect is that a customer can plug in a gateway and then devices on the downstream links from the gateway without any hands-on configuration by either the customer or the ISP. There seems to be pretty broad consensus among ISPs that this model describes the initial version of IPv6 service.
Check out draft-vandevelde-v6ops-nap-00.txt for more thoughts about why NATs are in use today and how IPv6 provides the same functions.
As Fred says, the IETF continues to identify specific needs - in this case, the need for minimal overhead to both the customer and the ISP for IPv6 service - get buy-in from the interested parties and develop solutions and standards for protocols that can meet those needs, such as the RFCs and Internet Drafts we've referred to in this thread...
- Ralph
At 10:29 AM 11/22/2004 -0800, Fred Baker wrote:
At 12:35 PM 11/22/04 -0500, Eric A. Hall wrote:One potentially technical hurdle here is the way that the device discovers that a range/block of addresses is available to it. Some kind of DHCP sub-lease, or maybe a collection of options (is it a range of addresses or an actual subnet? how big is it, and does that include net/bcast addresses?),is going to be required.
I think you're saying that the router/firewall/gateway thingie needs to have some sequence like:
- initial boot or expiration of previous lease occurs
- CPE router has or forms link-local association with upstream router
(note that a non-link-local address on the upstream interface is optional)
- CPE router sends DHCP request for configuration
- upstream router replies with address of DHCP server, DNS Server, and a
prefix with a lease. It also configures itself with a local route to that
prefix via CPE router.
- CPE router configures interior interface with said prefix and starts some
combination of autoconfiguration and DHCP configuration of downstream hosts.
- If Dynamic DNS is in use, some hosts may advise the DNS server of their
new address. If there is a management contract (ISP knows about and does
something with the CPE router), supplying the router's address upstream is
one possible use of DDNS.
Note that in the case that DDNS is in use and we are triggering off lease expiration, the process needs to take the concepts and issues of
http://www.ietf.org/internet-drafts/draft-ietf-v6ops-renumbering-procedure-02.txt into account.
I have added Ralph Droms to this. Ralph, your suggestion?
So it would obviously be useful that Linksys et al make sure that the specs are there to help them continue providing the same kind of high-value low-management experience. This is the kind of cross-industry participation I'm talking about needing.
I'll argue that this is pretty much what the IETF has always done. It comes down to "someone who sees the need propose a solution and make sure the other folks who are likely to be interested buy into it". It is fundamental to what we do.
_______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf