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Comment by drnick1 | Hacker News Reader

They are better for human consumption/understanding. Have you ever had to type an IPv6? It's awful.

How could you ever have really long addresses without having that problem?

They don't need to be really long. Adding one more octet to v4 makes it 1 trillion addresses. Sure the header should support longer than that, but it doesn't mean everyone needs to use all of it.

1 trillion addresses isn't anywhere near enough[1]. Remember that we're not talking about L2 here. (...I don't think 1 trillion MACs would even be enough if we want to ensure they're unique, and it seems the IEEE agree with me since they expanded MACs to 64 bits, but that's a different conversation.)

And you already don't have to use all 128 bits in v6. You're forced to use about 48 of them, but the rest is your choice. You can just... not use some of them. It's fine.

[1] https://www.rfc-editor.org/info/rfc1715/

The world is already managing with 32 bits of addresses plus NAT, and NAT most likely gives you less than 256 concurrent users per address. But sure, if some cheap ISP only owns a few /32s and needs to use more octets, let them do that, doesn't mean my 4-octet address needs to be super long too.

You're kinda forced to use 128 bits in v6 if you're an end user, cause that's the lowest common denominator. SLAAC is default, DHCP6 is widely unsupported. Most ISPs also only give out a /64 per spec minimum.

NAT is something you use when you're not managing.

The spec minimum is more like /56, so maybe you're forced to use slightly more than 48, but not all 128 bits.

Will you repeat the whole dance when you need a second extra octet? There are good reasons IPv6 is designed the way it is.

They considered 64 bit addresses at first but they didn't want to ever risk running out again so they doubled it again.

Try to remember it's not just about the sheer number of addresses - you also want to allocate them in big blocks so that few people ever need to expand their blocks, and they can split their big block into more blocks that are still big.

No, the field should be 128-bit to have headroom, but you don't need to hand out /128s to everyone. Everyone with a /32 now would be fine with /32 or /40.

How about /48

Oh wait that's the standard recommendation so it's already exactly how you said

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