Lawrence, You have a point... For this to work, we may have to do it after the longest prefix match rule, but limit the match to the upper 64 bits.
- Alain. > -----Original Message----- > From: Lawrence Zou [mailto:[EMAIL PROTECTED] > Sent: Tuesday, October 24, 2006 10:02 PM > To: 'James Carlson'; ipv6@ietf.org > Subject: RE: address selection and DHCPv6 > > I don't think we should amending rule 7 in such a way. > in fact , i think this will make the rule 8 unworkable. > according to RFC3484,when at last we have two source address > available,both can pass rule1-rule7,then,the rule 8 will > chose the longest match prefix.but if we amend rule 7 and > prefer manul-configured address,some thing changed,for example: > address A is autoconfigured and belong to ISP1,host use it > to access network of ISP1. > address B is manuconfigured and belong to ISP2,host use it to > access network of ISP2. > then if we prefer manuconfigured address ,we will chose > address B as source when we access ISP1,that maybe refused by > the PE router of ISP1 for the reason of soure address filter. > > > Best regards, > > Lawrence > > >-----Original Message----- > >From: James Carlson [mailto:[EMAIL PROTECTED] > >Sent: Wednesday, October 25, 2006 3:52 AM > >To: ipv6@ietf.org > >Subject: address selection and DHCPv6 > > > >I've done quite a bit of searching over the archives and over > >various web resources, but I haven't seen this issue addressed > >directly. > >Apologies if I've just missed it. > > > >RFC 3484 ("Default Address Selection for Internet Protocol version 6 > >(IPv6)") section 5 gives a set of ordered comparisons for > >source address selection. However, missing from this list is > >a distinction implied by RFCs 2461 and 2462: some systems may > >have a mix of addresses acquired by stateless address > >autoconfiguration, stateful > >(DHCPv6) configuration, and manual addressing. How are these > >distinguished? > > > >Rule 7 does address the temporary (RFC 3041) addresses, but > >what about these other flavors of addresses? Are they > >distinguished only by scope? > > > >Was this issue addressed and intentionally omitted from the > >RFC? (If so, I don't see it in the archives.) > > > >I suspect that some clients may need to distinguish among the > >various flavors here. I'd suggest amending Rule 7 to read: > > > > Rule 7: Prefer stable, public addresses. > > If SA is a manually-configured address and SB is automatic or > > temporary, then prefer SA. If SA is automatically configured via > > stateful (DHCPv6) methods and SB is automatically configured via > > stateless methods or temporary, then prefer SA. If SA is > > automatically configured via stateless methods and SB is > temporary, > > prefer SA. > > > > Similarly, if SB is a manually-configured address and SA is not, > > then prefer SB. If SB is stateful and SA is stateless or > > temporary, prefer SB. If SB is stateless and SA is temporary, > > prefer SB. > > > > When the application has the "prefer temporary address" flag > > enabled, all temporary addresses are (within this rule) elevated > in > > preference above manually-configured addresses. The other > > preferences are unaltered. (In other words, the preference order > > with this flag set becomes temporary first, then manual, stateful, > > and stateless last.) > > > >... or, to simplify, defining a "stability_of_address(A)" > >function that can work here. > > > >-- > >James Carlson, KISS Network > ><[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 > >-------------------------------------------------------------------- > > > > > > -------------------------------------------------------------------- > IETF IPv6 working group mailing list > ipv6@ietf.org > Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 > -------------------------------------------------------------------- > -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
