I imagine a bigger problem with your hypothetical might be the sheer mass of such a thing. Plus, you underestimate just how mind-bogglingly huge 2^64 is. (Grant

I imagine a bigger problem with your hypothetical might be the sheer mass of such a thing. Plus, you underestimate just how mind-bogglingly huge 2^64 is. (Granted, the IPv6 address space is going to very quite sparsely populated, but still.) I mean, the estimate on the number of atoms in the observable universe is "only" 10^80, for comparison.