The Sheer Size of IPV6

http://pthree.org/2009/03/08/the-sheer-size-of-ipv6/

by timf • 17 years ago

29 19 17 years ago

tptacek6• 17 years ago

Well this post sure makes an incisive point about the power of... successive powers of 2? We could add just 4 bits to IPv4 addresses and address any reasonable addressing argument, providing 10-20 static IP addresses for every man, woman, and child on the planet. That's not the challenge.

The challenges are:

* It is extremely painful to migrate from IPv4 to IPv6, not just because of the obvious stuff (like renumbering and upgrading routers) but also because tons of important programs are written to assume an IP address is 4 bytes long, or fits in a scalar data type.

* The argument for enduring that pain is weak. There are 6 billion people in the world, so we can't number them directly. But I haven't had a static IP address in years and years, and if you offered me an address out of 172/8 for my laptop I wouldn't take it. Most of the Internet works fine through NAT, and the trend is towards more NAT-friendliness.

* Any argument about the scarcity of IP addresses is clouded by the fact that IP addresses are doled out OPEC-style by a cartel of standards groups with an ideological bias towards hastening IPv6 adoption. There's no liquid market for netblocks, so we don't know what they're actually worth. Of course, if we had such a market, we'd probably find out that they're not worth all that much to people with laptops, and readily affordable for people with servers.

Put differently, in a vain attempt to steer this back to the topic at hand: you could make a similar point about the sheer size and flexibility of ASN.1 and X.500 directory naming schemes. But nobody's talking about chucking the DNS to get that.

trezor3• 17 years ago

While I'm not going to dismiss your argument entirely, it basically boils down to "Migrating to IPv6 is hard. Let's go shopping". Now the question which would be reasonable to ask is how hard would this migration actually be, coupled with how needed it actually is.

Right now you might say "There are 6 billion people in the world. Exploiting the existing address-space more efficiently, coupled with NAT will be 'good enough'". This may or may not be true as for now.

However, fast forward one generation, 30 years, whatever. Lets (optimistically? pessimistically?) assume world population is doubled. How about now? Will squeezing the existing address-space coupled with NAT be enough?

At this point there will be 3 people per IP address. And most people will probably have more networked devices than ever, accustomed to being able to work with data independent of network location.

Sure we can add hacks on hacks to make this viable, but at some point we will have to toss IPv4 out and accept that there will be a painful migration. At some point these hacks will cause more pain than a migration away from IPv4.

The question is not as much if we will have to ditch IPv4 but when. If your argument is that we have too much stuff which relies on current IPv4 configuration now, imagine in 30 years.

In short: Your primary concern is not going to get any better.

tptacek6• 17 years ago

First: "IPv6 is hard, let's go shopping" is exactly what happened on the Internet. Several hundred billion dollars later, nobody much cares about IPv6.

Second, when you make an point like "NAT may or may not be good enough", the onus is on you to support that point with evidence. Most of the problems NAT-unfriendly technologies were supposed to solve have instead been solved by brute force; HD movies move just fine over inefficient HTTP CDNs.

The rest of your comment just ignores my argument, which is that individuals don't need routable IP addresses for the Internet to work. Many of us never even use routable IP addresses. 6 billion, 10 billion, 20 billions --- as long as the next YouTube can get reachable servers online, what do I care whether my iPencil has a 1918 address?

Networking technologies are "hacks" when they challenge the greybeard orthodoxy, and they're "sound engineering" when they don't. It's funny how quickly we forgot that the Internet itself was a pragmatic reaction to OSI standards. You want to see a "hack"? How about, the NSF decides that commercial entities shouldn't connect to the NSF backbone, and the entire Internet splits in two, and I can't get to University sites from Ripco in Chicago? Guess how long ago that happened? Sorry if I can't get all worked up over whether my phone can talk to your phone over direct BitTorrent.

klahnako• 17 years ago

Should have compared cubes instead of squares

jodrellblank• 17 years ago

With 128bit addresses, it makes it the same size as the GUID address space, and betterexplained.com has this to say:

http://betterexplained.com/articles/the-quick-guide-to-guids...

"Think about how big the Internet is: Google has billions of web pages in its index. Let’s call it a trillion (10^12) for kicks. Think about every wikipedia article, every news item on CNN, every product in Amazon, every blog post from any author. We can assign a GUID for each of these documents.

Now let’s say everyone on Earth gets their own copy of the internet, to keep track of their stuff. Even crazier, let’s say each person gets their own copy of the internet every second. How long can we go on?

Over a billion years.

Let me say that again. Each person gets a personal copy of the internet, every second, for a billion years."

sam_in_nyc2• 17 years ago

I think it's pretty amazing that you'd have to have a 52ft x 52ft monitor to display all of the addresses in IPv4... and that 88% of the pixels on the screen would represent a device hooked up to the internet, right now.

wmf2• 17 years ago

That's an oversimplification, since not all assigned addresses are used.

sam_in_nyc2• 17 years ago

I guess I'll just have to wait another year to be amazed. :(

The Sheer Size of IPV6

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