Hi, Doug, Please see inline.
2013-02-04 à 18:37, Doug Barton <[email protected]> : > On 02/04/2013 12:38 AM, Rémi Després wrote: >> It remains that IIDs having u=1 SHOULD be unique, i.e. with rare enough >> exceptions. This is somewhat similar to the expectation that ULA collisions >> shouldn't be seen). >> >> This theoretical unicity has been extensively used to assign stable IIDs, >> without administrative action, to hosts that have no privacy constraints >> requiring the opposite. > > What software exists that makes determinations based on the u bit? (*) Major OSes can assign IIDs derived from IEEE MAC addresses of their LAN adapters (if not by default, at least as a possibility). They do it because of what IEEE and IETF have specified, each one for its own domain, concerning their respective u bits. With these specifications, it is impossible on a SLAAC link that two hosts that have universal-scope addresses (necessarily different if they communicate at the MAC layer), would have conflicting IIDs at the IP layer if they derive them from MAC addresses. > > How would that software be impacted if the u bit were suddenly be devoid of > meaning? Hosts would become free to assign arbitrary IIDs having u=1, breaking applicability of (*) above. > > I am of course assuming that DAD would still be in play for dynamically > assigned addresses, which it seems we are all in agreement on. Sure (agreement confirmed). Hope it clarifies. RD > > Doug > -------------------------------------------------------------------- > IETF IPv6 working group mailing list > [email protected] > Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 > -------------------------------------------------------------------- -------------------------------------------------------------------- IETF IPv6 working group mailing list [email protected] Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
