> Unless anyone can mention a lot of potential IPv6 deployments that will > deploy IPv6 without a router sending RA, it's not even worth discussing > the subject.
ISATAP links have routers that send RAs, but not all nodes on the link will necessarily receive them. A node on an ISATAP link can always send an RS to get back an RA, but why bother when the information is available via DHCP? > Don't tell me one will deploy DHCPv6 hosts without a router > in the deployment Not hearing unsolicited RAs is not the same thing as not having routers. > - don't give me private closed networks for an example > - it's a weak argument. Even a dinky home network I can build in my home > for IPv6 better have the Linksys router sending RA's to IPv6 hosts in my > home. OK. > If a router is deployed, then why disable the RA on the router? I > agree with James that such a RA-absent network is plain broken. It's not about disabling RA on the router at all; the routers are just ordinary routers and will still send RAs just fine. Fred [EMAIL PROTECTED] > My union statement has been qualified by "if a network has RA and > DHCPv6, both, sending prefix lengths". If such a scenario happens, then > what choice does one have but to resolve discrepancies in data provided > by two sources but to use some sort of union. > > From day one, I am with James and Bernie, that DHCPv6 should not add any > more options towards prefix information or gateway. Let only RA provide > prefix information. > > Hemant > > -----Original Message----- > From: James Carlson [mailto:[EMAIL PROTECTED] > Sent: Friday, August 17, 2007 12:34 PM > To: Hemant Singh (shemant) > Cc: Templin, Fred L; Iljitsch van Beijnum; [EMAIL PROTECTED]; > ipv6@ietf.org; JINMEI Tatuya / ???? > Subject: RE: [dhcwg] Re: prefix length determination for DHCPv6 > > Hemant Singh (shemant) writes: > > Thanks, James. I agree with Fred then that a node can try > DHCPv6. But > > now how does the node get a prefix length? As you are saying, some > > manual or static configuration can be used. I certainly > don't like the > > > host to assume any prefix length in this scenario. Since I am not a > > fan of any manual configuration, it does make sense, only > for such a > > case of absence of an RA, that DHCPv6 provides prefix length. Since > > DHCPv6 doesn't know if the network's router will issue RA's or not, > > then DHCPv6 has to provide prefix length all the time. > > My view on it is that such a network is just plain broken. V6 seems > intentionally designed to assume that networks have routers, because > routers are the _authoritative_ source of prefixes (they have to route > them). > > Thus, it's a case I test for, and one I make sure "works," > but I assume > that it's useless. In my own implementation, you end up with a > /128 for that interface. If you have a default route, everything will > go there (via the link-locals), and you'll get a pile of redirects for > the local hosts. If you don't, then you're just sunk. Enjoy the > address, because it's all you've got. ;-} > > > Then I am for what Iljitsch is saying. If a host see a > discrepancy in > > prefix lengths from RA and DHCPv6, then host has to decide > based on a > > union of information. > > "Union" doesn't make much sense to me. That just provides a needless > opportunity for error, and consequent bizarre and hard-to-diagnose > behavior out of subsets of hosts on a network that get the wrong data. > > -- > James Carlson, Solaris Networking > <[EMAIL PROTECTED]> > Sun Microsystems / 1 Network Drive 71.232W Vox +1 > 781 442 2084 > MS UBUR02-212 / Burlington MA 01803-2757 42.496N Fax +1 > 781 442 1677 > -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
