> I can read one at a glance and the other makes me fill in the blanks myself after having to count how many invisible blanks I need to fill in.

The protocol chosen for IPng, SIPP, did actually have "only" 64 bits, but this was deemed not enough as folks did not want to have to worry about running out again (amongst other reasons), and so tweaked it to have a fixed 128 bits:

* https://datatracker.ietf.org/doc/html/rfc1752

SIPP originally was variable-length capable, but it was decided fixed-length was better (e.g., for hardware like ASICs).

> Wouldn't have been a problem if they hadn't given every square millimeter of the planet 100 billion addresses.

For the record: IPv6 gives 10¹⁷ addresses per mm²; in terms of volume, 10⁸ IPv6 addresses per mm³ throughout the Earth.

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wpm 3 hours ago | parent [-]

You're right, my 100B per square millimeter undershot by six orders of magnitude.

I woulda thought 18 quintillion would've been enough addresses for the next century or two but good thing we locked in all this extra data we throw away with a '::'.

I'm sure it was all well considered by intelligent people, but it was still a dumb decision.

	▲	ndriscoll 3 hours ago \| parent [-]
		What problem does 128 bits cause? Just that you don't like :: for a run of 0s? Do you need to care about ipv6 addresses in your work? Because I can tell you that when I'm trying to design simple, efficient routing and firewall rules (with e.g. 100s of thousands of endpoints across different datacenters on different continents), it's really nice to be able to subnet things the way I'd like instead of the way I must to squeeze things into the space I have, and not have to worry about backing myself into a corner later because I gave the wrong number of bits to various dimensions. And worst case, if you somehow got it wrong, just give yourself an entire /64 or more to try again, with it being compatible with what you did (no need to do a phased migration that requires reclamation as you go along). Like I only tangentially interact with this stuff, but I can't imagine how a network operator wouldn't prefer we live in an all ipv6 world.