Wrt: >Either way: You need to know the customer's address. A DHCPv6 server off in the weeds does not necessarily know what link local address the client is >using (because it might change without notification).
If the client performed DHCPv6 with server, and the deployment includes a relay agent between client and server, then the peer-address between relay and server lets the server know what is the link-local address of the client. Also each time the link-local address of the client changes for a DHCPv6 client, the client will reinitiate DHCPv6 which lets the server know again what the latest link-local address is. If you are talking about a more generalized DHCPv6 deployment, then show us a topology and we can discuss it. As for broadband operators and untrusted devices in residential homes, one plan for IPv6 cable MSO's is to dole out a PD to an eRouter cable modem. The PD is doled out by DHCPv6 server. DHCPv6 Lease Query protocol can verify the cable modem eRouter traffic by sending a query by address from relay to server. A query by address will return the client information for either that client that has been assigned that address *OR* been delegated a prefix that contains that address. See the URL below for details on DHCPv6 Lease Query protocol. http://www.ietf.org/internet-drafts/draft-ietf-dhc-dhcpv6-leasequery-01. txt Hemant -----Original Message----- From: David W. Hankins [mailto:[EMAIL PROTECTED] Sent: Wednesday, August 15, 2007 3:02 PM To: [EMAIL PROTECTED] Cc: [email protected] Subject: Re: [dhcwg] Re: prefix length determination for DHCPv6 On Wed, Aug 15, 2007 at 02:16:31PM -0400, James Carlson wrote: > Ole Troan writes: > > >> If you delegate a prefix, then you route to the prefix -- best match. > > > > > > Yes, but how does that route get in the table, and what next-hop > > > is set? You have to know your customer's address eventually. > > > > next-hop is the link-local address though. > > Right; it's the link-local address of the router to which you've > delegated the prefix. Well, sometimes. It depends what you're doing. Either way: You need to know the customer's address. A DHCPv6 server off in the weeds does not necessarily know what link local address the client is using (because it might change without notification). It may know what global addresses the client is using (because it allocated them), but won't if router solicition is in use. A router solicitation system certainly doesn't have any knowledge of which customer is which nor what addresses global or not which they're using. This is but one facet of a network's operation: try not to focus on it too much. There are potentially a multitude of reasons to know which of your customers are online, and how to reach them. Testing connectivity alone (such as during a support call). > It's not the address of every single machine on the customer's > network. In fact, knowing the addresses of the machines on the > customer's network is useless, as it doesn't tell you the address of > that CPE router. I'm not sure why you make this declaration (twice now), when no one has suggested the counterpositive. Maybe I misunderstood Iljitsch. > Obvious sorts of ways to get this would be to keep track of your > delegations or (alternatively) use an appropriate routing protocol. Which I think gets us back to what Iljitsch said in the first place, except that realistically ISPs are going to find it difficult and/or costly to trust routing information from eg broadband customers, so really what you're looking at is some way to provide a register of your customers' current addresses. -- Ash bugud-gul durbatuluk agh burzum-ishi krimpatul. -- David W. Hankins "If you don't do it right the first time, Software Engineer you'll just have to do it again." Internet Systems Consortium, Inc. -- Jack T. Hankins -------------------------------------------------------------------- IETF IPv6 working group mailing list [email protected] Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
