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Mail from an IPv6 host to an IPv4 host

2004-08-28 15:33:00
Koen Martens wrote:

I'm not in the position of correcting you if you're wrong, I've just
recently started testing with ipv6 again after a year or so of having it
put aside for a while.

I am not an IPv6 expert either.

Why, is my question to you, does the sender not know the ipv4 address
the receiver will see? How does this work when a ipv6 only host connects
to an ipv4 server?

When an IPv6 host talks to an IPv4 host then this goes through a decice that
does the required Network Address Translation - Protocol Translation
(NAT-PT) (see RFC 2766, and also 1933). So the IPv6 host will not see the
IPv4 address and vice versa. Different IPv4 hosts talking to the same IPv6
host will see a different IPv4 addresses dependent on the NAT-PT device
inbetween.

This is similar to the NAT in IPv4. For example you cannot find out the IP
address of my server that is is behind a NAT router (except by asking me).

Roger


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