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Comment by saulpw | Hacker News Reader

It's not just you, I completely agree. 128-bit addresses are overkill. 64-bit would have been fine, and yes, backwards-compatible would have gotten us there that much sooner. For me, it's a deal-breaker that I can't reasonably speak an IPv6 address aloud (for instance when doing tech support over the phone).

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How does your backwards-compatibility dream handle ASICs built to handle only IPv4 and shitty middleboxes hard-coded to drop or -worse- mangle any IP traffic that doesn't fit a particular subset of what's permissible for IPv4?

Google and other big players go to huge lengths to build new Internet protocols on top of UDP because enough of the internet drops or mangles anything other than TCP or UDP that it's effectively impossible to use anything else on the Greater Internet. IPvNext by way of backwards-compatible IPv4 was (and continues to be) no easier than doing something that's backwards-incompatible.

As a bonus, doing the backwards-incompatible thing bypasses all the bad behavior of existing shitty middleboxes and crummy ASICs.

There is literally no way to get more than 4 bytes of address space out of midleware routers that limit the addresses to 4 bytes. There is no way to make that backwards compatible.

Overkill is good! It's impossible to get the size exactly correct; your only options are "too small" or "too big". Given how difficult it is to deploy a new L3 protocol, why wouldn't we pick the size that ensures we don't have to turn around and do it again immediately afterwards?

> backwards-compatible would have gotten us there that much sooner

v6 is already backwards compatible. Between dual stack, Teredo, 6to4, 6rd, 6over4, ISATAP, 6in4/4in6, NAT64/DNS64, 464xlat, DS-lite, MAP-T/E, 4rd, LW4over6 and probably other things I'm forgetting, you could make a reasonable argument that it's too backwards compatible, even.

If you meant "v4 being forwards-compatible would have gotten us there sooner", then yes, I agree. It's unfortunate it's not. That's entirely v4's fault though, not v6's.

You aren't supposed to be manually assigning addresses except in very small networks. You should have that centrally managed by DNS or any number of other things. No one should have to speak their address to you. You don't know what you're doing.

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