![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
So what is this IPv6 anyway?
Dec. 18th, 2008 11:34 amSince a bunch of you said in the poll that you don't know what IPv6 is, I may as well have a shot at explaining. I'll try to keep it as non-technical as I can.
To begin with, a little bit of terminology. "IP" in this context stands for "Internet Protocol". The "v6" just means "version six". What your computer used to get the page you're currently reading was the previous version, "Internet Protocol version four" or "IPv4". For all practical purposes, IPv4 is what the entire Internet uses today.
Everything on the Internet has an address. The LiveJournal servers has addresses. Your computer has an address. If you don't have an address you can neither send nor receive stuff. When your computer wants to send something somewhere (like, for example, a request for the LJ servers to send your friends page back), it sticks the message it wants to send into a package, puts the destination address on the package and hands it off. Lots of other stuff will then make sure the package gets to its destination.
The basic problem here is that there is a limited space to write the address in. The addresses are numbers, and in IPv4 the possible addresses are the numbers from 0 to 4294967295. So there can never be more than a bit under 4.3 billion IPv4 things on the Internet. In practice, a lot of the addresses get lost to technical details, so the maximum useful number is probably closer to 3 billion. Which may sound like a lot. It is a lot. Unfortunately, the Internet has become very popular. About 85% of the possible addresses have already been assigned. Because of the way the addresses are handed out, it won't happen that one we day we just run out. Rather, there's going to be a pretty drawn-out period where it becomes harder and harder to get new addresses. The first milestone in this process, when the world-level authority runs out of addresses to hand down to the continent-level authorities, is currently estimated to come in late February 2011.
So, you say, why don't we just add more numbers? And, indeed, that's exactly the plan. In order to do that, everything on the Internet needs to be taught to understand the new address format. And since we're doing that, the opportunity was taken to change a few other things as well. The result, the new address label format, is called IPv6.
IPv6 has more possible addresses than IPv4. A lot more. I'm not going to make numerical comparisons, partly because the numbers become impossible to visualize and partly because different distribution schemes will lead to a lot of them never even being meant to be used. Let it suffice to say that we'll not run out of addresses again for centuries or more, even if we decide to give all molecules in our homes addresses of their own.
Ok, fine. So why aren't we switching over to the new addresses, then, you may ask. And the answer is, of course, money. Remember that bit above about teaching everything on the Internet the new address format? That's a big job. For some things, like just about all personal computers today, it's easy. If you're running an operating system released in the past five years or so, your machine can almost certainly handle IPv6. The problem is everything else. The stuff that actually gets the packets your machine sends from you to LiveJournal. Much of that equipment is very expensive. It needs to be very, very fast, so it has understanding of the IPv4 format built into the hardware. Which means that to deal as quickly with IPv6, it'll need to be replaced. Which, for the entire Internet, becomes a huge investment. Which nobody wants to do until they have to.
Incidentally, that last bit almost certainly means that we in the West will be the last ones to change over. Since the Internet was built here, and to begin with four billion addresses sounded like more than anyone would ever need, most of the addresses were given to organizations and companies here. Those who came later got less. IBM has as many addresses as all of Africa, for example. Which is why the first large public event to exclusively use IPv6 for its networking was the Olympic Games in Beijing this summer.
So. Anyway. That's IPv6. Wider address labels for the Internet, in a nutshell.
To begin with, a little bit of terminology. "IP" in this context stands for "Internet Protocol". The "v6" just means "version six". What your computer used to get the page you're currently reading was the previous version, "Internet Protocol version four" or "IPv4". For all practical purposes, IPv4 is what the entire Internet uses today.
Everything on the Internet has an address. The LiveJournal servers has addresses. Your computer has an address. If you don't have an address you can neither send nor receive stuff. When your computer wants to send something somewhere (like, for example, a request for the LJ servers to send your friends page back), it sticks the message it wants to send into a package, puts the destination address on the package and hands it off. Lots of other stuff will then make sure the package gets to its destination.
The basic problem here is that there is a limited space to write the address in. The addresses are numbers, and in IPv4 the possible addresses are the numbers from 0 to 4294967295. So there can never be more than a bit under 4.3 billion IPv4 things on the Internet. In practice, a lot of the addresses get lost to technical details, so the maximum useful number is probably closer to 3 billion. Which may sound like a lot. It is a lot. Unfortunately, the Internet has become very popular. About 85% of the possible addresses have already been assigned. Because of the way the addresses are handed out, it won't happen that one we day we just run out. Rather, there's going to be a pretty drawn-out period where it becomes harder and harder to get new addresses. The first milestone in this process, when the world-level authority runs out of addresses to hand down to the continent-level authorities, is currently estimated to come in late February 2011.
So, you say, why don't we just add more numbers? And, indeed, that's exactly the plan. In order to do that, everything on the Internet needs to be taught to understand the new address format. And since we're doing that, the opportunity was taken to change a few other things as well. The result, the new address label format, is called IPv6.
IPv6 has more possible addresses than IPv4. A lot more. I'm not going to make numerical comparisons, partly because the numbers become impossible to visualize and partly because different distribution schemes will lead to a lot of them never even being meant to be used. Let it suffice to say that we'll not run out of addresses again for centuries or more, even if we decide to give all molecules in our homes addresses of their own.
Ok, fine. So why aren't we switching over to the new addresses, then, you may ask. And the answer is, of course, money. Remember that bit above about teaching everything on the Internet the new address format? That's a big job. For some things, like just about all personal computers today, it's easy. If you're running an operating system released in the past five years or so, your machine can almost certainly handle IPv6. The problem is everything else. The stuff that actually gets the packets your machine sends from you to LiveJournal. Much of that equipment is very expensive. It needs to be very, very fast, so it has understanding of the IPv4 format built into the hardware. Which means that to deal as quickly with IPv6, it'll need to be replaced. Which, for the entire Internet, becomes a huge investment. Which nobody wants to do until they have to.
Incidentally, that last bit almost certainly means that we in the West will be the last ones to change over. Since the Internet was built here, and to begin with four billion addresses sounded like more than anyone would ever need, most of the addresses were given to organizations and companies here. Those who came later got less. IBM has as many addresses as all of Africa, for example. Which is why the first large public event to exclusively use IPv6 for its networking was the Olympic Games in Beijing this summer.
So. Anyway. That's IPv6. Wider address labels for the Internet, in a nutshell.
