> > The default is still to use public addresses not temporary > addresses, > > although implementations MAY reverse this default if they want to > > emphasize privacy over application compatibility. > > > I'm wondering why having an escape clause that only apply > to that particular rule.
First, note that most of the source address slection rules are SHOULD requirements. (The "prefer matching scope" rule being an exception - it's MUST.) An implementation can violate a SHOULD requirement - from RFC 2119: 3. SHOULD This word, or the adjective "RECOMMENDED", mean that there may exist valid reasons in particular circumstances to ignore a particular item, but the full implications must be understood and carefully weighed before choosing a different course. So even without the explicit escape clause, an implementor could decide given their implementation's particular circumstances to prefer temporary addresses over public addresses. Second, note that this escape clause has been there for more than a year (since version 04) and already passed WG & IETF last calls. The reason for having the explicit escape clause is that this rule has been the subject of much discussion in the WG & IESG; some feel that privacy is the overriding concern and some feel that application compatibility is more important. We have a rough consensus to favor application compatibility by default. But as a member of the privacy camp, I think it's helpful to remind implementors that if in their particular circumstances privacy is more important than app compatibility, then they can prefer temporary addresses by default. Rich -------------------------------------------------------------------- IETF IPng Working Group Mailing List IPng Home Page: http://playground.sun.com/ipng FTP archive: ftp://playground.sun.com/pub/ipng Direct all administrative requests to [EMAIL PROTECTED] --------------------------------------------------------------------
