Le Friday 14 March 2008 00:27:26 Pekka Savola, vous avez écrit : > This issue was first reported about 5 years ago by Alain Durand et al and > yet there is no fix yet (and no mention in the default address selection > problem statement), see section 2 of: > http://tools.ietf.org/html/draft-ietf-v6ops-v6onbydefault-03 > > The main problem is destination address selection rule 2 which requires > that source and destination address scopes must match (which in the case of > v4 private and global addresses is not a very useful comparison given the > prevalence of NAT).
Indeed. And this was (inconclusively) discussed at the mike during the last v6ops meeting. I had also asked about this a few months ago. Nobody seemed to care (winter vacation?): http://www.ops.ietf.org/lists/v6ops/v6ops.2007/msg01150.html > Maybe we need a more systematic approach to deal with RFC3484 issues (as > in, a numbered list of all the problems noted) instead of doing a nice new > features to have PPT slideshow every IETF meeting. I think we need to "simplify" RFC3484 section 3.2 through removing the IPv4 site-local scope there: we'd be left with only global scope (public addresses + RFC1918) and link-local scope (169.254.0.0/16). I suspect some implementors (at least Windows) already ignore §3.2 for the sake of reliability. I know Linux does implement ¼3.2 to the letter of the RFC unfortunately. And I have seen people _remove_ AAAA from their server's DNS records because of this issue, combined with deficient 6to4 relays. Another problem involves incomplete implementation of RFC3484: some stacks apply RFC3484 for IPv6, in connect() and sendto() socket APIs, but fail to do RFC3484 in getaddrinfo(), and simply assume IPv6 is first, and IPv4 second. I suspect this applies to OSX and BSDs, and also "embedded" C run-times. These two issues are different, though they effectively have the same result: favor IPv6 over IPv4, when IPv4 should be favored over IPv6 (IMHO). -- Rémi Denis-Courmont -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
