|
On 8/15/19 3:33 AM, shyam bandyopadhyay wrote:
The answer is no, they cannot, particularly not if either address
assignment or routing are hierarchical. It remains to be seen whether 128 bits is sufficient. I'd place
even odds on an extension to IPv6 to permit addresses longer than
128 bits, gaining favor while I'm still alive. (Though it's also possible that global climate change will eventually make even 32 bits more than enough.. But it doesn't seem prudent to presume that.) More generally, any decision made long in the past can always be
second-guessed. But the people who insist that a different
decision should have been made, have little reason to have
confidence in their belief. After all, they didn't have the
burden of making their preferred choices work in the real world.
It's also hard to believe that with nearly 25 years of painful
investment in IPv6, dual-stack transition, and NAT, with
plenty of accumulated evidence that IPv6 actually does (mostly)
work better than the alternatives, that people are going to
somehow abandon all of that investment for a completely new packet
format that has the worst features of both IPv4 and IPv6 -
insufficient address space AND transition burden. To put it
differently, IPv6 is going to have to fail a lot worse than it
has, before there's sufficient interest to face another
transition. And while anything is possible, IPv6 really was
designed to last for several decades (and with the assumption that
human population AND internet appliances will continue to grow
exponentially). 64bit addresses were considered for IPng, and
that would have likely been the choice had they appeared to be
sufficient. Keith
|
