> % Let me try an rephrase my question. I would like to know if there is > % consensus on the architectural view that IPv6 should have addresses with > % different scopes?
No, there is definitely not consensus on that point. There are three big classes of arguments. The first class of argument is more against "ambiguous addresses" than scoped addresses: using ambiguity as a surrogate for unreachability is unnecessary (firewall can do that on any address) and inconvenient (ambiguity of addresses makes several error scenarios undecipherable). The second class of argument relates to routing and network management. Maintaining scoped addresses makes routing hard, especially if a node has to support multiple instantiations of a given scope. Margaret also developed an argument about the need to maintain a site convex, and the interaction of that requirement with shortest path routing. The third class of argument considers the use of addresses by applications. Using scoped addresses forces applications to understand scopes, which is much more complex and error prone than just considering that all addresses are equal. > % Again, I fail to see how deprecating site-local addresses (specifically > the > % FEC0::/10 prefix) solves the underlying problem (e2e communications > failing > % with some src/dst address pairs). Everybody should know that, and Bill is perfectly correct: just because an address is globally unique does not mean it is reachable. However, if it is unique, you eliminate a number of the error cases caused by ambiguity. -- Christian Huitema -------------------------------------------------------------------- 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] --------------------------------------------------------------------
