I get so many Second System Syndrome vibes off of IPv6. Surely other people must be picking it up too.

Future proofing it by jumping straight to 128 bits instead of 64. 64 would have been fine. Even with a load factor of 1:1000 by assigning semantics to ranges of IP addresses, 64 bit addressing is still enough addresses for 10 million devices per person.

If we become a galactic empire, we will have to replace the Web anyway because every interaction will have to be a standalone app or edge networking that doesn’t need to hear back from the central office for minutes, hours, days anyway. We could NAT every planet and go on forever.

The point is not really to support a galactic empire, the idea is that you have a network part and an interface part, each is 64 bits. The "network" part is used by routers, the interface part is to identify the device on the endpoint. Each interface have an identifier that is world unique (usually based on the MAC address), each network is also unique. Usually, your ISP gives you a /48 prefix, so you have 16 bits for potentially 64k internal networks. This way, you don't need something like DHCP to get an address, you just take it and you won't have conflicts.

But because you have two independent unique parts, you need twice as many bits, so 64+64=128 bits. It simplifies routing and address allocation, at the cost of 16 bytes per packet compared to 64 bit addresses.

That we could use IPv6 on galactic empires is an added bonus, but not really the reason.

> Future proofing it by jumping straight to 128 bits instead of 64. 64 would have been fine. Even with a load factor of 1:1000 by assigning semantics to ranges of IP addresses, 64 bit addressing is still enough addresses for 10 million devices per person.

128 bit is like the least of adoption issues and basically meaningless difference vs 64.

But it shows weird priorities when they decided 128 then immediately wasted half of it on host part just to achieve "globally unique" host part that isn't really all that useful characteristic of the protocol.

Don't think the problem is 64 vs 128. I don't think the problem is end users either, the vast majority of which don't even know what the IP protocol is in the first place (nor should they). The fault I think is on ISPs.

I use hyperoptic in the UK, if you replace the original router (which reserves the external 443 port for itself, i.e. no one sophisticated would keep it), there seems to be no way to get a v6 address. This is pure incompetence and carelessness. Like ISPs allowing their network to send packets spoofing IPs from outside their network. Add to that foreign ISPs (which means that even if your own network supports v6, you need v4 support when you are on holidays/travelling), and you have a situation where v4 cannot simply be switched off.

So for a website, what is the point of supporting v6 if v4 is never going away?

It's understandable that IPv6 would be ambitious rather than incremental given the cost of rolling out a new protocol; the bells-and-whistles IPv6 design is probably just a relatively small constant factor more expensive than the simplest possible address space expansion. Viewed that way, you only get the one chance to update the protocol, you might as well fix whatever you can.

how would you do SLAAC with 64 bits?

> Future proofing it by jumping straight to 128 bits instead of 64.

It's hard to disagree with your point since 64 would definitely have been better than the 32 we have. I'm not convinced the choice of going for 128 bits posed any real challenge to adoption though.