Jeroen Massar wrote :
Rémi Després wrote:Why ???Because ::x.x.x.x and ::ffff:x.x.x.x are IPv4, it is not IPv6.
IMO too general to be sufficient
Consider in particular a dual stack site with a private IPv4 space. Its CPE, which has a NATv4-v4, may also have a NATv6-v4.If it has one, and if it uses it for outgoing packets that have 0::/64::/96 you mean I guess ;)
No.Routing is in general performed on 64 bits (the remainder is IID, IMU not candiadate to be part of a prefix).
But no objection to /96 where it is supported.
destinations, IPv6-only hosts on the LAN can establish connections with IPv6 *AND* IPv4 remote hosts.Why are you trying to translate IPv4 -> IPv6 to IPv4 and introduce state at the two translators, not even thinking of the mess it has to create for NATting these packets? You can simply do IPv4 -> IPv4.
I don't!If you read carefully, you will see that IPv6 host reach IPv4 hosts via only one NAT (v6-v4).
IMHO this is nice and clean.That is very dirty in my opinion.
Matter of taste then.But at least this lets a real *IPv6-only* hostto reach an IPv4-only server, e.g. in HTTP.
I copied this URL, pasted it in Mozilla thunderbird, and reached the (obsolete) document. Either you were wrong in being "pretty sure" (once more ??) or your browser, or your OS, has a problem.On the other hand, reasons for such a definite statement as "never a mapped address on any wire" have to be presented.How do you write your firewall? The user has IPv4 enabled, they have a working IPv4 firewall. IPv6 gets enabled, and suddenly the IPv4 firewall is completely moot as it can be bypassed by sending those packets as IPv6 in the ::/96 range. Ouch.The reference I know on the subject isfile:///Users/Pro/Documents/_%20TECHNIQUE%20/IPv6-IPv4/MSG%20Itojun%20Hagino%20-%20Mapped%20addresses%20Considered%20Harmful00301.htmlI am pretty sure I can't reach that location.
Regards Rémi