Well the IPv4 spec only allows 4 octets, so having 5 or more is impossible. We could fix it by changing the protocol, but at that point it’s more worth it to just migrate to IPv6.
3.1 IP Addresses, versions 4 and 6
In the good old days back when Ben Kenobi was still called Obi Wan Kenobi, there was a wonderful network routing system called The Internet Protocol Version 4, also called IPv4. It had addresses made up of four bytes (A.K.A. four “octets”), and was commonly written in “dots and numbers” form, like so: 192.0.2.111.
You’ve probably seen it around.
In fact, as of this writing, virtually every site on the Internet uses IPv4.
Everyone, including Obi Wan, was happy. Things were great, until some naysayer by the name of Vint Cerf warned everyone that we were about to run out of IPv4 addresses!
(Besides warning everyone of the Coming IPv4 Apocalypse Of Doom And Gloom, Vint Cerf14 is also well-known for being The Father Of The Internet. So I really am in no position to second-guess his judgment.)
Run out of addresses? How could this be? I mean, there are like billions of IP addresses in a 32-bit IPv4 address. Do we really have billions of computers out there?
Yes.
Also, in the beginning, when there were only a few computers and everyone thought a billion was an impossibly large number, some big organizations were generously allocated millions of IP addresses for their own use. (Such as Xerox, MIT, Ford, HP, IBM, GE, AT&T, and some little company called Apple, to name a few.)
In fact, if it weren’t for several stopgap measures, we would have run out a long time ago.
But now we’re living in an era where we’re talking about every human having an IP address, every computer, every calculator, every phone, every parking meter, and (why not) every puppy dog, as well.
And so, IPv6 was born. Since Vint Cerf is probably immortal (even if his physical form should pass on, heaven forbid, he is probably already existing as some kind of hyper-intelligent ELIZA15 program out in the depths of the Internet2), no one wants to have to hear him say again “I told you so” if we don’t have enough addresses in the next version of the Internet Protocol.
What does this suggest to you?
That we need a lot more addresses. That we need not just twice as many addresses, not a billion times as many, not a thousand trillion times as many, but 79 MILLION BILLION TRILLION times as many possible addresses! That’ll show ’em!
You’re saying, “Beej, is that true? I have every reason to disbelieve large numbers.” Well, the difference between 32 bits and 128 bits might not sound like a lot; it’s only 96 more bits, right? But remember, we’re talking powers here: 32 bits represents some 4 billion numbers (232), while 128 bits represents about 340 trillion trillion trillion numbers (for real, 2128). That’s like a million IPv4 Internets for every single star in the Universe.
wouldn’t surprise me if we end up in a situation where individual programs have their own IP. then individual variables, so different programs in different networks can access them.
that might actually end up consuming all the addresses
…
stupid suggestion. just saying that future technologies might figure up a way to fuck this up again
Yeah, the Universe keep making bigger fools (of us all). But, we should still use IPv6 instead of clawing the tattered remains of IPv4. I just wish my ISP agreed.
I think that’s a bad objection. It’s idealistic in the worst way, it’s making “Perfect […] the enemy of the good”. Plus, there are significant practical advantages to a fixed-length addressing scheme, and any fixed-length going to have a maximum. So, under the constraint of fixed-length addressing “big enough” is all we have.
128 bits really is quite hard to fill up, we’ll have to worry about a lot of very different things before the run out of addresses. Like speed-of-light latency vs. TCP (and possibly TLS session) timers for interplanetary connections.
Well the IPv4 spec only allows 4 octets, so having 5 or more is impossible. We could fix it by changing the protocol, but at that point it’s more worth it to just migrate to IPv6.
fair, but isn’t IPv6 just going with the same assumption as IPv4, “so many addresses, no way we will ever use them all”
It’s pretty hard to overstate just how many addresses are in the ipv6 address space vs ipv4.
One of my favorite descriptions comes from Beej’s guide to network programming, something I first read probably in the early to mid 2000s. https://beej.us/guide/bgnet/html/#ip-addresses-versions-4-and-6
For every IPv4 address, IPv6 has 18 quintillion IPv4 Internets.
But, sure, it might be possible for us to fsck up allocations, again.
wouldn’t surprise me if we end up in a situation where individual programs have their own IP. then individual variables, so different programs in different networks can access them.
that might actually end up consuming all the addresses …
stupid suggestion. just saying that future technologies might figure up a way to fuck this up again
Yeah, the Universe keep making bigger fools (of us all). But, we should still use IPv6 instead of clawing the tattered remains of IPv4. I just wish my ISP agreed.
without a doubt ipv6 is an improvement. only loss is that it’s humanely possible to remember ipv4 addressed, but that ain’t necessary.
my only “objection” is that an actual solution should accommodate unlimited growth, rather than what we consider a big enough number.
I think that’s a bad objection. It’s idealistic in the worst way, it’s making “Perfect […] the enemy of the good”. Plus, there are significant practical advantages to a fixed-length addressing scheme, and any fixed-length going to have a maximum. So, under the constraint of fixed-length addressing “big enough” is all we have.
128 bits really is quite hard to fill up, we’ll have to worry about a lot of very different things before the run out of addresses. Like speed-of-light latency vs. TCP (and possibly TLS session) timers for interplanetary connections.
There’s enough V6 addresses for every atom on the planet and enough spare to do it 100x over. We’ll be fine.
going to gave each atom in the solar system its own IP address.
checkmate
They didn’t read xkcd 865, I guess. Or maybe they did.
there’s always a relevant XKCD