On Tue, 29 Jan 2002, Hesham Soliman (ERA) wrote: > > 3) IMO, it's a bit questionable to use IPv4-mapped > > addresses like this > > anyway. IPv4-mapped addresses should only be used (apart > > from e.g. SIIT > > definition) as a node's internal representation for IPv4 > > address; for > > better compatibility, the node should use: > > > > u=http://10.2.12.126/marsII > > > > => But this does not look like an IPv6 address > for an IPv6-only node. The SIIT case you > mentioned above is an example where this > would not work.
See below. > > (this way the receiving IPv6 node can decide the mechanism > > to reach the > > IPv4-address; that is, if u= can contain either IPv4 or > > IPv6 address) I'll restate this: this depends on the definition of u=. If 'u' can have: 1) only IPv6 addresses, using mapped address is fine 2) either iPv6 or IPv4 address, IMO IPv4 should be used when _sending_ the packet We're arguing about point 2). My point is that if address can be either, some nodes [a dual stack] can receive values with u=[ipv4] _anyway_, and must be able to cope with them. > => The 'network' must give an indication > of the mechanism to be used. If you use > NAT-PT then you'll always see IPv6 > addresses, if you use SIIT then you will > see the mapped addresses, which will dictate > certain actions by the IPv6-only device. [snip rest] Yeah, but the draft isn't about what the packet will look like after it has been mangled by NAT-PT or SIIT -- what should be best when sent by some node. It's clear that if an IPv6-only node sees a packet, u= must be an IPv6 address of _some_ form (if it's supposed to be reachable). -- Pekka Savola "Tell me of difficulties surmounted, Netcore Oy not those you stumble over and fall" Systems. Networks. Security. -- Robert Jordan: A Crown of Swords -------------------------------------------------------------------- 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] --------------------------------------------------------------------
