> What the parent is saying is that had they implemented a scheme like IPv6 at the time, it would have been problematic for hardware reasons, so it wouldn't hav

> What the parent is saying is that had they implemented a scheme like IPv6 at the time, it would have been problematic for hardware reasons, so it wouldn't have made sense. He's right. There is some spectacular failure of communication here. What I am definitely not saying: they should have implemented IPv6 in 1978! What you are apparently somehow reading: they should have implemented IPv6 in 1978! Here's what I am saying: Some decisions made in 1978 have, with the perspective of time, had unfortunate, unforeseeable consequences. This doesn't mean that IPv4 should have had a bloody 128 bit address space in 1978. Rather, it means that, with the perspective of time, we can see that some decisions made have really had dire consequences, and that what would have been counter-intuitive or less than optimal decisions at the time would have worked out better in the long run. For instance, given the hardware limitations of the time, it would have worked out better in the long run if IPv4 had had a bit smaller address space. At 2^24, it would have lasted well into the early/mid-90s but needed to be replaced right around the huge growth spike, before anything got too entrenched, when there was ample opportunity to roll out a different addressing scheme. 2^32 has left us in an uncomfortable spot where it was big enough to have got us quite far and for us to have become incredibly dependent on it, but that means we also have really, really entrenched a lot of legacy hardware in everyone's homes and offices, and it's not big enough to allow have the world to not live behind carrier-grade NAT.