On Oct 9, 2007, at 8:49 AM, Ralph Droms wrote:
is it provable that no design for a follow-on to IPv4 would have
provided that backward compatibility?
I don't know about 'provable', but there's a strong argument as to
why that's challenging.
Any new design would have necessarily required more bits to address
more end systems. Making legacy systems interact with these
additional addressing bits without some form of gateway, NAT or other
translation would indeed be challenging. You're literally trying to
expand the size of the namespace that a legacy implementation will
And, I guess I'll stop here as I'm rehashing a train that long ago
left the station...
While the train has left the station, it seems like it can still be
modified while in motion.
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