Martin Rex wrote:
It was the IETFs very own decision to build IPv6 in a fashion that it is
not transparently backwards compatible with IPv4. If the is anyone to
blame for the current situation, than it is the IETF, not the consumers
or the ISPs (except for those folks at ISPs who participated in the
development of IPv6).
People say this from time to time, but it's a complete myth.
IPv4 provides no mechanism whatever for addresses greater than 32 bits.
Therefore, mathematically, there is no possible design for an IP with
bigger addresses that is transparently backwards compatible. We've known
that since at least 1992.
The design error was made in the late 1970s, when Louis Pouzin's advice
that catenet addresses should be variable length, with a format prefix,
was not taken during the design of IPv4.
(There were advocates of variable length addresses for IPng, but the
128 bit choice won on the grounds that it is enough for anything, which
32 bits clearly wasn't.)
Brian (donning flameproof clothing)
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