WEBVTT - An Update On IPv6 0:00:04.160 --> 0:00:07.480 Get in tech with technology with tech Stuff from stuff 0:00:07.520 --> 0:00:14.000 works dot com. Hey there, and welcome to tex Stuff. 0:00:14.040 --> 0:00:17.680 I'm your host, Jonathan Strickland. I'm an executive producer over 0:00:17.760 --> 0:00:20.160 at how Stuff Works and I love all things tech, 0:00:20.640 --> 0:00:24.520 and today we're going to talk about a pretty technical subject. 0:00:24.600 --> 0:00:26.440 And just to get this out of the way, I 0:00:26.520 --> 0:00:30.600 am getting over a cold and it's pollen season here 0:00:30.640 --> 0:00:35.640 in Atlanta already, so I might sound a little extra 0:00:35.720 --> 0:00:39.440 grungy today. Uh just just blame that on on my 0:00:39.520 --> 0:00:43.839 health and Nirvana. But recently a listener asked me to 0:00:43.920 --> 0:00:47.760 give an update on the switchover to I p V six, 0:00:47.760 --> 0:00:50.320 which I thought presented a great opportunity to talk about 0:00:50.400 --> 0:00:53.800 what that actually means, why it's important, as well as 0:00:54.200 --> 0:00:57.520 what progress has been made in this switchover. Now. It 0:00:57.560 --> 0:01:01.320 all boils down to solving April saying problem, which is 0:01:01.400 --> 0:01:04.040 that the old set of rules we relied upon for 0:01:04.080 --> 0:01:07.679 the Internet just aren't quite sufficient to keep up with 0:01:07.760 --> 0:01:11.640 the way we're using the Internet. So first we need 0:01:11.680 --> 0:01:15.520 to define what is i P. It stands for Internet Protocol, 0:01:15.720 --> 0:01:19.560 which sounds a little daunting, but really that just means 0:01:19.640 --> 0:01:22.440 it's the method or set of rules that the Internet 0:01:22.480 --> 0:01:26.280 follows in order to send data between computers or other 0:01:26.319 --> 0:01:30.399 devices that are interconnected within this network of networks. In 0:01:30.480 --> 0:01:34.600 protocol speak, we typically refer to these devices as hosts, 0:01:35.319 --> 0:01:38.040 and from a high level, the rules are pretty straightforward, 0:01:38.120 --> 0:01:41.360 but they are absolutely necessary. Without these rules, it would 0:01:41.360 --> 0:01:44.640 be pretty challenging to find what you're looking for when 0:01:44.680 --> 0:01:47.040 you connect to the Internet. So let's take a very 0:01:47.120 --> 0:01:50.240 simple connection and that way we can build on that 0:01:50.280 --> 0:01:53.240 to understand what the challenges are. Back in the good 0:01:53.240 --> 0:01:56.840 old Bolton Board System days, the BBS days, you would 0:01:56.880 --> 0:02:00.800 typically have one machine acting like a server. Everything would 0:02:01.080 --> 0:02:05.160 live on that machine and it would serve data to 0:02:05.280 --> 0:02:08.280 a single client at a time. So that meant you 0:02:08.320 --> 0:02:12.240 add one computer or host in the terminology of the Internet, 0:02:12.639 --> 0:02:15.680 and this one is the server that has all the 0:02:15.720 --> 0:02:19.680 message boards, files, games, whatever the Bolton Board System might have. 0:02:20.520 --> 0:02:24.200 The people who want to visit the BBS would use 0:02:24.240 --> 0:02:27.240 a dial up modem on their personal computer. This is 0:02:27.240 --> 0:02:30.600 another host in Internet parlance, but we also would call 0:02:30.639 --> 0:02:33.080 it a client and they would use that to call 0:02:33.320 --> 0:02:37.280 up the server computer over a normal phone line. So 0:02:37.360 --> 0:02:39.160 it's just like if you were to make a phone 0:02:39.160 --> 0:02:43.079 call to somebody else. The connection was direct, or at 0:02:43.200 --> 0:02:45.520 least as direct as a connection can be when it 0:02:45.520 --> 0:02:49.840 crosses over telecommunications infrastructure like phone lines. The point is 0:02:50.280 --> 0:02:54.720 the client and server communicated directly with one another. The 0:02:54.800 --> 0:02:57.880 data didn't need to pass through any third party hosts. 0:02:58.240 --> 0:03:02.000 A good analogy is the old two cans and a 0:03:02.120 --> 0:03:04.920 string method of communication. You know, you got a can 0:03:04.919 --> 0:03:06.440 on one side and a can on the other, string 0:03:06.480 --> 0:03:08.720 connecting the two, and you speak, and the vibrations go 0:03:08.800 --> 0:03:11.160 through the string and are amplified on the other side, 0:03:11.200 --> 0:03:14.000 and thus you can talk well. The two computers in 0:03:14.000 --> 0:03:17.600 this example are those cans, and the phone infrastructure would 0:03:17.639 --> 0:03:22.960 be the string. But the Internet consists of millions of computers, 0:03:22.960 --> 0:03:26.799 plus routers and switches and other devices that are all 0:03:26.880 --> 0:03:30.720 interconnected in various ways. Whenever you visit a website or 0:03:30.800 --> 0:03:33.359 you send an email, you're sending and receiving data to 0:03:33.680 --> 0:03:36.560 and from other devices connected to that network, and some 0:03:36.680 --> 0:03:39.520 of them might be across the world from each other, 0:03:39.800 --> 0:03:42.280 which means there have to be rules in place for 0:03:42.320 --> 0:03:45.880 your messages to get to the right computers, and those 0:03:45.880 --> 0:03:48.280 computers have to know where to send the data back 0:03:48.440 --> 0:03:52.720 to you in response to your requests. Part of the 0:03:52.760 --> 0:03:56.840 Internet protocol addresses this very issue, and yes, that is 0:03:56.960 --> 0:04:00.560 kind of a pun. It's called IP addresses. An IP 0:04:00.720 --> 0:04:05.320 address is a unique identifier for every computer or connected 0:04:05.360 --> 0:04:10.120 device on the Internet. Uh, anything that's directly communicating with 0:04:10.240 --> 0:04:13.000 the Internet has to have an IP address, and it's 0:04:13.040 --> 0:04:15.880 similar to a physical address that we would use for 0:04:16.040 --> 0:04:19.600 mailing things in that it provides a means for computers 0:04:19.640 --> 0:04:23.320 to locate the right destination for data. But unlike a 0:04:23.400 --> 0:04:27.360 physical address, a machine's IP address doesn't necessarily always stay 0:04:27.440 --> 0:04:30.760 the same. It can it can be a static IP address, 0:04:30.800 --> 0:04:34.560 but it's pretty common to run into dynamic IP addresses, 0:04:34.720 --> 0:04:37.479 which means they can change depending upon the local network 0:04:37.600 --> 0:04:41.200 that it connects to the router that's in charge. Lots 0:04:41.200 --> 0:04:45.080 of different things can determine what a machine's IP address 0:04:45.240 --> 0:04:48.320 is at any given time. Now, the idea for IP 0:04:48.400 --> 0:04:52.159 addresses goes back much further than most people's experience with 0:04:52.279 --> 0:04:55.640 the Internet, unless you were a researcher or an engineer. 0:04:56.000 --> 0:04:58.640 The debut of the Worldwide Web in the early nineties 0:04:58.720 --> 0:05:01.880 kind of helped usher in a new era of computer users, 0:05:01.920 --> 0:05:05.159 but the Internet itself had been around for a decade 0:05:05.360 --> 0:05:08.440 before the Web was a thing. Those rules had to 0:05:08.480 --> 0:05:10.640 be in place for the Internet to work, and they were, 0:05:10.720 --> 0:05:13.480 in fact an evolution of the rules that engineers were 0:05:13.520 --> 0:05:17.400 creating when they built the predecessor to the Internet, called 0:05:17.400 --> 0:05:21.480 our Bonnet. Our Bonnet was a Department of Defense project. 0:05:21.680 --> 0:05:24.200 Those working on the project, we're creating the framework and 0:05:24.320 --> 0:05:29.440 rules within which different computers built on different architectures could 0:05:29.520 --> 0:05:34.200 meaningfully communicate across a network. This was a pretty hefty undertaking, 0:05:34.279 --> 0:05:37.119 but I've talked about it in other episodes of Tech Stuff, 0:05:37.120 --> 0:05:39.320 so I'm not gonna go all the way through that 0:05:39.400 --> 0:05:42.080 again right here and right now. You can find the 0:05:42.080 --> 0:05:44.440 episodes on our Bonnet and listen to those. But in 0:05:44.520 --> 0:05:48.960 a Request for Comments document and r FC document dating 0:05:49.000 --> 0:05:52.800 from nineteen eighty, the team working on Internet protocols detailed 0:05:52.839 --> 0:05:56.719 the necessity for addresses and helped clarify their role. Part 0:05:56.720 --> 0:05:59.880 of that meant explaining what an address is and is not. 0:06:00.400 --> 0:06:03.440 So here's a quote, a direct quote from RFC seven 0:06:03.520 --> 0:06:08.640 sixty and yes, fasten your seat belts because it's really 0:06:08.680 --> 0:06:13.400 exciting speech. A distinction is made between names, addresses, and routes. 0:06:13.800 --> 0:06:18.000 A name indicates what we seek, an address indicates where 0:06:18.080 --> 0:06:21.919 it is. A route indicates how to get there. The 0:06:21.960 --> 0:06:26.080 Internet protocol deals primarily with addresses. Is the task of 0:06:26.240 --> 0:06:30.440 higher level i e. Host to host or application protocols 0:06:30.760 --> 0:06:34.760 to make the mapping from names to addresses, and so 0:06:34.800 --> 0:06:37.039 a device would need a name and an address. The 0:06:37.120 --> 0:06:39.520 route would be the pathway the data would take between 0:06:39.520 --> 0:06:42.400 the hosts. Now, this isn't all that different from sending 0:06:42.480 --> 0:06:45.480 snail mail in the real world. You can't just put 0:06:45.520 --> 0:06:47.760 an envelope in a mailbox with a person's name on 0:06:47.800 --> 0:06:50.080 it and expect the postal service to be able to 0:06:50.120 --> 0:06:53.320 deliver it, unless I guess the name is Santa clause 0:06:53.839 --> 0:06:56.440 you need to include an address on the envelope. The 0:06:56.480 --> 0:06:59.760 postal service then takes the collected outgoing mail and to 0:06:59.800 --> 0:07:02.200 turn emens how to deliver it, which is not that 0:07:02.320 --> 0:07:06.360 different from how computers send data across the Internet. Now, 0:07:06.400 --> 0:07:08.920 one thing that is a little different is how devices 0:07:08.920 --> 0:07:11.720 on the Internet package data when they send it across 0:07:11.760 --> 0:07:14.920 the Internet. Devices on the Internet send data in small 0:07:15.040 --> 0:07:19.480 batches called packets. These packets are sort of like puzzle pieces. 0:07:19.520 --> 0:07:21.960 They don't all have to take the same pathway to 0:07:22.000 --> 0:07:26.200 get to their destination, where they are then reassembled into 0:07:26.240 --> 0:07:28.480 whatever it is that you were sending. It's a pretty 0:07:28.600 --> 0:07:31.360 ingenious design that helps avoid problems when a particular machine 0:07:31.360 --> 0:07:34.520 on the network goes down. But let's get back to addresses, 0:07:34.560 --> 0:07:37.800 because that's kind of a separate topic. In this request 0:07:37.840 --> 0:07:41.000 for comments, the group also mentioned that addresses were a 0:07:41.080 --> 0:07:46.160 fixed length of four octets or thirty two bits. Now, 0:07:46.200 --> 0:07:50.240 a bit is a single unit of information. It can 0:07:50.280 --> 0:07:53.200 take the form of a zero or a one. So 0:07:53.280 --> 0:07:57.120 the team would refine this a bit in future RFC documents, 0:07:57.160 --> 0:08:02.200 but for the time being four octets or four uh 0:08:02.240 --> 0:08:06.360 eight bits four bytes. In other words, the thirty two 0:08:06.360 --> 0:08:09.480 bits gave the team a lot of potential addresses to 0:08:09.520 --> 0:08:12.960 play with. So each bit can have one of two states, 0:08:13.000 --> 0:08:15.040 that being a zero or a one, and there are 0:08:15.120 --> 0:08:17.040 thirty two of them total. So what you would do 0:08:17.120 --> 0:08:20.320 is you take to the states and raise it to 0:08:20.320 --> 0:08:22.440 the power of thirty two the number of bits. That 0:08:22.560 --> 0:08:26.840 gives you a grand total of four billion, two hundred 0:08:27.000 --> 0:08:31.040 ninety four million, nine hundred sixty seven thousand, two hundred 0:08:31.120 --> 0:08:36.000 ninety six addresses. Almost Now why do I say almost, 0:08:36.320 --> 0:08:39.400 because not all of those addresses are actually available to 0:08:39.520 --> 0:08:43.160 the general world. The protocol reserves nearly two hundred ninety 0:08:43.200 --> 0:08:46.800 million addresses for specialized purposes, but still more than four 0:08:46.840 --> 0:08:49.280 billion addresses. Seemed like they were going to be plenty 0:08:49.520 --> 0:08:52.520 way back in nineteen eighty. Now, the way we typically 0:08:52.559 --> 0:08:55.040 see those addresses written out is in a series of 0:08:55.080 --> 0:08:59.080 decimal numbers separated by periods. For example, you might see 0:08:59.080 --> 0:09:04.520 an address like this two hundred sixteen dot dot sixty 0:09:04.600 --> 0:09:09.080 one dot seven. Those are your four octets, except they're 0:09:09.080 --> 0:09:13.840 being represented as decimal numbers, not as bits. So you'll 0:09:13.840 --> 0:09:16.600 never see a number higher than two hundred fifty five 0:09:16.760 --> 0:09:19.880 in any of those four spots. And why is that, Well, 0:09:19.880 --> 0:09:24.480 it's because the highest number eight bets can represent would 0:09:24.480 --> 0:09:30.120 be two fifty six. So you start with zero, you 0:09:30.160 --> 0:09:32.480 can go up to two five. If we started with 0:09:32.559 --> 0:09:34.120 just one and built up, we could go all the 0:09:34.120 --> 0:09:35.760 way up to two fifty six. But we start with 0:09:35.880 --> 0:09:38.559 zero because we're talking about base ten, so once you 0:09:38.640 --> 0:09:40.280 hit nine, you need to be able to flip back 0:09:40.280 --> 0:09:43.520 over to zero. So two five is the largest number 0:09:43.600 --> 0:09:46.320 that can occupy any of those four spots. If we 0:09:46.360 --> 0:09:48.760 wrote out that same IP address I just mentioned the 0:09:48.920 --> 0:09:52.720 to sixteen dot seven dot sixty one dot one seven, 0:09:52.880 --> 0:09:55.480 it would look like this in binary code, and I 0:09:55.520 --> 0:09:57.800 apologize ahead of time because you're gonna hear a lot 0:09:57.840 --> 0:10:00.760 of ones and zeros, guys. But this is why they 0:10:00.800 --> 0:10:03.920 decided to switch over to a decimal based system for notation. 0:10:04.160 --> 0:10:08.200 The binary address would be one one zero one one 0:10:08.559 --> 0:10:13.960 zero zero zero, dot zero zero zero one one zero 0:10:14.040 --> 0:10:19.160 one one dot zero zero one one one one zero 0:10:19.240 --> 0:10:24.040 one dot one zero zero zero one zero zero one. 0:10:24.440 --> 0:10:26.600 And yes, it sounds like I just did the binary 0:10:26.679 --> 0:10:29.800 solo from the humans are dead by fly of the concords. 0:10:30.320 --> 0:10:32.960 It doesn't exactly roll off the tongue, so you can 0:10:33.000 --> 0:10:35.320 see why the team decided to go with that decimal 0:10:35.360 --> 0:10:39.079 based system. Now, at a higher level than the Internet protocol, 0:10:39.360 --> 0:10:41.319 there are rules in place that allow us to use 0:10:41.360 --> 0:10:44.480 stuff like domain names and file pathways to make it 0:10:44.559 --> 0:10:48.000 easier to direct emails or go web browsing to where 0:10:48.040 --> 0:10:51.559 we want to go. In tim Burners, Lee introduced the 0:10:51.600 --> 0:10:54.719 concept of uniform resource locators or u r l s. 0:10:55.200 --> 0:10:56.760 But all of that is just a way to make 0:10:56.760 --> 0:11:00.120 it easier for us humans to navigate the Internet and 0:11:00.160 --> 0:11:03.000 the Web. On the machine level, it's all about the bits, 0:11:03.440 --> 0:11:06.200 all right. So we have our four octets of bits, 0:11:06.280 --> 0:11:10.360 each representing a decimal number in that series of four numbers. 0:11:10.400 --> 0:11:13.200 This set of rules was part of the fourth version 0:11:13.360 --> 0:11:16.600 of the Internet Protocol, so we tend to call these 0:11:16.720 --> 0:11:21.760 i p v four addresses or just IP address for short. Typically, 0:11:21.800 --> 0:11:24.400 if someone says IP address, they're talking about i p 0:11:24.640 --> 0:11:27.839 v four. So what happened to versions one through three, Well, 0:11:27.840 --> 0:11:31.199 those were all experimental versions of Internet Protocol that were 0:11:31.200 --> 0:11:35.400 never rolled out for general public use. Now, originally IPv 0:11:35.559 --> 0:11:38.520 four divided up the octets to designate networks and hosts. 0:11:38.960 --> 0:11:41.760 In other words, part of the address would tell the 0:11:41.800 --> 0:11:46.160 system which network your computer was on, and the rest 0:11:46.200 --> 0:11:49.120 of the address would be specific to your actual computer 0:11:49.320 --> 0:11:53.079 on that network. Because remember, the Internet is a network 0:11:53.320 --> 0:11:57.320 of networks. It's not like each computer is just independently 0:11:57.880 --> 0:12:03.240 plugging into a giant web of data. These are hierarchies 0:12:03.280 --> 0:12:05.920 that we're looking at. So this is not again that 0:12:06.080 --> 0:12:09.040 different from an address on an envelope, because on an 0:12:09.040 --> 0:12:12.600 address and an envelope you'll have general information such as 0:12:12.679 --> 0:12:15.560 a country, a state, a city, that kind of thing, 0:12:16.040 --> 0:12:19.679 and then more specific information like a house number and 0:12:19.760 --> 0:12:22.880 a street that sort of thing. So again, very similar 0:12:22.920 --> 0:12:25.800 to the way physical mail works. But even early on 0:12:25.880 --> 0:12:29.120 while before the Web. The team working on Internet Protocol 0:12:29.240 --> 0:12:31.760 realized that this was going to limit the useful number 0:12:31.760 --> 0:12:34.280 of addresses a bit too much, and so in nine 0:12:34.960 --> 0:12:39.040 they redefined the approach by creating five classes of networks. 0:12:39.040 --> 0:12:43.360 They designated the classes from A to E. This became 0:12:43.400 --> 0:12:47.120 known as class full networking. Now, classes D and E 0:12:47.360 --> 0:12:50.240 contained the reserved addresses I talked about before. Some of 0:12:50.240 --> 0:12:53.640 them were for uh experimental purposes and some of them 0:12:53.679 --> 0:12:57.319 were reserved for other reasons. Classes A through C use 0:12:57.400 --> 0:13:01.439 different bit lengths to designate specific networks. This removed the 0:13:01.480 --> 0:13:03.520 tight restriction on the number of networks that could join 0:13:03.520 --> 0:13:06.199 the Internet using IPD four, which up to that point 0:13:06.200 --> 0:13:09.080 had been a measly two fifty six networks. If the 0:13:09.120 --> 0:13:11.920 Internet only consisted of two ft six networks, we never 0:13:11.960 --> 0:13:15.600 would have had to worry about adding this change. But 0:13:15.920 --> 0:13:18.640 clearly that was not going to stay the same now. 0:13:18.800 --> 0:13:22.160 If you connect your computer directly to your Internet service provider, 0:13:22.440 --> 0:13:25.120 also known as your I s P, your computer would 0:13:25.120 --> 0:13:27.880 get an IP address from that I s P. It 0:13:27.880 --> 0:13:32.040 would have some sort of designation for this, but many 0:13:32.120 --> 0:13:35.679 people are using routers or connecting to the network through 0:13:35.920 --> 0:13:38.880 another network that has its own router, and in these cases, 0:13:39.200 --> 0:13:42.720 the router has an IP address specific to it and 0:13:42.760 --> 0:13:46.240 typically creates a subnetwork for all the devices or nodes 0:13:46.280 --> 0:13:50.120 that connect through that router. So let's take our little 0:13:50.160 --> 0:13:53.640 example again. So let's say your computer's IP address is 0:13:53.679 --> 0:13:57.360 currently set to to sixty seven dot sixty one dot 0:13:57.400 --> 0:14:00.440 one seven, and in this example, we'll say your network's 0:14:00.480 --> 0:14:04.400 identity is represented in the first three octets, so that 0:14:04.440 --> 0:14:09.920 means your network's identity is to sixteen dot dot sixty one. 0:14:10.400 --> 0:14:14.360 The final octet designates the node on that network, in 0:14:14.400 --> 0:14:17.840 other words, your computer, So you could theoretically have any 0:14:17.920 --> 0:14:22.320 value from dot zero as the final one to dot to. 0:14:23.200 --> 0:14:25.680 Now I say theoretically because this is a Class C 0:14:26.000 --> 0:14:28.960 network and as such may not have an ending in 0:14:29.080 --> 0:14:31.240 zero or two fifty five. But that gets a little 0:14:31.240 --> 0:14:33.880 too technical. The computers on the network use a set 0:14:33.880 --> 0:14:37.359 of rules called a subnet mask to separate the octets 0:14:37.400 --> 0:14:41.920 that indicate networks versus nodes. Uh sub net masks in 0:14:42.320 --> 0:14:44.720 I p V four follow up patterns. So the first 0:14:44.720 --> 0:14:47.960 such mask is two five five dot zero dot zero 0:14:48.080 --> 0:14:53.000 dot zero. This mask reserves eight bits to designate the networks. 0:14:53.040 --> 0:14:55.920 That eight bits is in that first octet, the number 0:14:55.960 --> 0:14:59.520 that's represented in there is two five, and then it 0:14:59.600 --> 0:15:03.040 reserves the other twenty four bits to designate nodes, So 0:15:03.080 --> 0:15:05.640 that would be a Class A network. On the flip side, 0:15:06.000 --> 0:15:08.440 you have two five five dot two five five dot 0:15:08.480 --> 0:15:11.240 two five five dot zero. That would mean you would 0:15:11.240 --> 0:15:15.480 have twenty four bits the first three octets to designate 0:15:15.560 --> 0:15:19.480 the network and only eight bits to designate the various nodes. 0:15:19.520 --> 0:15:22.280 This would be a Class C network. These are called 0:15:22.320 --> 0:15:25.320 masks because they guide routers to look at specific numbers 0:15:25.360 --> 0:15:28.400 within the addresses, and by looking only at the numbers 0:15:28.440 --> 0:15:31.200 that are pertinent to the network, the routers can save 0:15:31.240 --> 0:15:33.560 some time. They don't have to process an entire thirty 0:15:33.560 --> 0:15:35.120 two bit address. They just look at the bit of 0:15:35.160 --> 0:15:38.240 the address that's important. Again, going back to the postal service, 0:15:38.520 --> 0:15:41.200 this would be like if you had UH two major 0:15:41.240 --> 0:15:43.360 piles and one of them is for local mail and 0:15:43.400 --> 0:15:46.040 the other is for non local mail, and you look 0:15:46.040 --> 0:15:48.360 at the address and just by looking at the bottom 0:15:48.400 --> 0:15:51.160 line where you look at the the state, you know 0:15:51.400 --> 0:15:53.280 is it local or nonlocal, and so you just do 0:15:53.360 --> 0:15:55.960 a quick sorting that way. It's kind of similar to that. 0:15:56.160 --> 0:15:58.640 But why would we have all these different classes. Anyway, 0:15:58.720 --> 0:16:01.200 let's all in how a network work gets set up. 0:16:01.240 --> 0:16:04.640 So a network administrator would make these sort of determinations. Uh, 0:16:04.680 --> 0:16:06.920 if a network is going to have a lot of subnets, 0:16:06.960 --> 0:16:10.800 you need more bits to designate networks. If the subnets 0:16:10.840 --> 0:16:12.840 are going to have a lot of nodes, that is, 0:16:13.080 --> 0:16:15.880 computers connected to those subnets, then you would need to 0:16:15.880 --> 0:16:19.720 dedicate more bits for the node or a computer side 0:16:19.720 --> 0:16:22.400 of things. It's all dependent upon the infrastructure of the network. 0:16:22.840 --> 0:16:25.240 I'll explain a little bit more, but first, why don't 0:16:25.240 --> 0:16:35.120 we take a quick break to thank our sponsor. All Right, 0:16:35.200 --> 0:16:38.560 on the Internet itself, only the network part of an 0:16:38.560 --> 0:16:43.200 IP address is important. Uh, the the Internet machines don't 0:16:43.280 --> 0:16:47.040 care about your specific computers address. They just need to 0:16:47.040 --> 0:16:49.400 know what network it needs to go to. Data will 0:16:49.440 --> 0:16:52.480 move toward that appropriate network, and once it's there, the 0:16:52.520 --> 0:16:55.600 host part of the address then becomes important. It's it's 0:16:55.640 --> 0:16:57.360 kind of like once you get the mail to the 0:16:57.440 --> 0:17:00.000 right state, then you need to start dividing it up 0:17:00.000 --> 0:17:03.000 by a city and thus neighborhood and that kind of thing. 0:17:03.760 --> 0:17:07.320 IP addresses can be static, which means they don't change, 0:17:07.600 --> 0:17:09.960 or they can be dynamic, meaning they get assigned every 0:17:09.960 --> 0:17:12.840 time the device connects to the Internet. Most devices in 0:17:12.880 --> 0:17:16.040 the hands of consumers use dynamic IP addresses, and many 0:17:16.080 --> 0:17:19.680 are connected to sub networks or subnets, which are networks 0:17:19.680 --> 0:17:23.399 that share a common network address. A single company might 0:17:23.520 --> 0:17:28.560 use subnets to share a single network address across all subnets, 0:17:28.560 --> 0:17:31.480 even if they are geographically distant from one another, and 0:17:31.520 --> 0:17:34.200 that helps conserve the number of network addresses that are 0:17:34.240 --> 0:17:38.280 generally available. Even so, it didn't take very long for 0:17:38.359 --> 0:17:40.679 the engineering team to realize that thirty two bits was 0:17:40.680 --> 0:17:42.879 a big limiting factor, and so they set about to 0:17:42.920 --> 0:17:45.480 solve this problem. Otherwise, the world would reach a limit 0:17:45.520 --> 0:17:48.320 on the number of useful addresses, and no new networks 0:17:48.320 --> 0:17:50.480 would be able to join the Internet. It would have 0:17:50.600 --> 0:17:55.000 hit capacity. So with IPv four addresses again, we have 0:17:55.119 --> 0:17:58.320 a little bit more than four billion available ones once 0:17:58.359 --> 0:18:01.280 you take away the ones that have been reserved for 0:18:01.320 --> 0:18:04.680 other purposes. A billion is admittedly a very large number, 0:18:04.720 --> 0:18:07.200 but not nearly large enough. Even in the late eighties 0:18:07.200 --> 0:18:10.359 and early nineties, engineers were saying this is gonna be 0:18:10.359 --> 0:18:13.320 a problem. Things were changing quickly, and it soon became 0:18:13.359 --> 0:18:16.040 clear that we'd hit a real crunch with IP addresses. 0:18:16.080 --> 0:18:18.800 For one thing, there was an emerging trend of moving 0:18:18.840 --> 0:18:23.000 from an on demand connection to the Internet to pervasive connections. 0:18:23.560 --> 0:18:25.320 Now by that I mean in the early days, you 0:18:25.320 --> 0:18:27.960 would typically use a dial up modem to connect to 0:18:28.000 --> 0:18:30.639 the Internet, and frequently this meant that you were engaging 0:18:30.720 --> 0:18:34.400 your homes one phone line so that you could call 0:18:34.560 --> 0:18:37.879 up an Internet server and browse the Internet. So you 0:18:37.880 --> 0:18:40.800 wouldn't stay on it forever because you need that phone 0:18:40.840 --> 0:18:44.400 line for other things, and frankly, you could end up 0:18:44.560 --> 0:18:46.399 racking up big charges if you were on for a 0:18:46.400 --> 0:18:50.120 really long time, so you would typically hang up when 0:18:50.119 --> 0:18:52.880 you were done. Now hanging up meant that you were 0:18:53.040 --> 0:18:55.240 you had just freed up an IP address. You didn't 0:18:55.240 --> 0:18:58.320 need that IP address anymore because you were no longer 0:18:58.320 --> 0:19:01.560 connected to the Internet. So even if you had more 0:19:01.600 --> 0:19:03.760 people than you had I P addresses, not everyone was 0:19:03.800 --> 0:19:05.480 going to be connected at the same time, and so 0:19:05.520 --> 0:19:08.119 you can kind of fudge things a little bit. But 0:19:08.200 --> 0:19:11.280 then we gradually began to move toward more broadband connections 0:19:11.400 --> 0:19:14.600 using things besides just dial up modems, and we also 0:19:14.640 --> 0:19:17.480 started to make a move towards always connected devices. Now 0:19:17.520 --> 0:19:20.360 this is even more true today when you have everything 0:19:20.400 --> 0:19:23.480 from set top boxes like video game consoles, to wireless 0:19:23.520 --> 0:19:26.320 devices like smart thrum, the stats and home security devices 0:19:26.320 --> 0:19:29.080 to add in. Then there's an added problem that any 0:19:29.119 --> 0:19:31.679 device that has multiple ways to connect to the Internet 0:19:31.800 --> 0:19:36.080 needs a different i p address for each of those methods. So, 0:19:36.200 --> 0:19:39.159 for example, if you have a smartphone that connects to 0:19:39.200 --> 0:19:43.879 an LTE network as well as to a WiFi router UH, 0:19:43.920 --> 0:19:46.200 it has to have an IP address for each of those, 0:19:46.359 --> 0:19:47.919 Or if you have a laptop that has both a 0:19:47.920 --> 0:19:50.920 wired and a wireless connection, has to have an IP 0:19:50.960 --> 0:19:53.560 address for each of those, So a single device can 0:19:53.600 --> 0:19:56.760 take up more than one IP address. And of course 0:19:56.800 --> 0:19:59.080 the other big challenge was that more of the world 0:19:59.160 --> 0:20:02.760 was going online. The Internet when it first got started 0:20:02.840 --> 0:20:08.600 was kind of an exclusive club, really nerdy exclusive club, 0:20:08.640 --> 0:20:11.840 but still exclusive. But now it was going global, so 0:20:11.880 --> 0:20:13.720 there were just a lot more people trying to connect 0:20:13.720 --> 0:20:18.199 and a new method of addressing was needed. In the 0:20:18.200 --> 0:20:21.760 Internet Engineering Task Force developed the successor to i p 0:20:21.920 --> 0:20:24.840 V four. This one was called i p V six, 0:20:25.240 --> 0:20:28.400 So that immediately raises a question, why the heck did 0:20:28.400 --> 0:20:31.800 we jump from four to six. Well, what would have 0:20:31.880 --> 0:20:35.359 been Internet Protocol five was an Internet stream protocol that 0:20:35.440 --> 0:20:38.800 was in development as far back as the late seventies. Ultimately, 0:20:38.840 --> 0:20:41.479 that protocol never rolled out for public use, and it 0:20:41.520 --> 0:20:45.520 also was never adopted as i p V five officially. 0:20:45.600 --> 0:20:47.640 But back then no one was really sure how things 0:20:47.640 --> 0:20:49.080 were going to turn out, and so they went with 0:20:49.119 --> 0:20:51.560 i p V six to be safe. It expanded that 0:20:51.640 --> 0:20:55.879 bit number for addresses from thirty two to one twenty eight, 0:20:56.480 --> 0:20:59.160 and they don't look like i p V four addresses either, 0:20:59.600 --> 0:21:03.159 and I V six address consists of eight groups of 0:21:03.280 --> 0:21:10.280 four hexadecimal digits. The hexadecimal system is a base sixteen system. 0:21:10.640 --> 0:21:12.760 So with a base ten system, you start at zero, 0:21:12.840 --> 0:21:15.400 you go up to nine, and then you start over right, 0:21:15.640 --> 0:21:18.320 ten is just one zero, and then you can go 0:21:18.400 --> 0:21:21.080 up to nineteen, which is just one nine, and then 0:21:21.080 --> 0:21:23.280 you start over again. Now you go to twenty, which 0:21:23.320 --> 0:21:27.080 is to zero, and over and over again. Now hexadecimal 0:21:27.720 --> 0:21:30.199 goes up to sixteen, but you really can't show that 0:21:30.280 --> 0:21:33.959 using just decimal numerals. It doesn't work that way. So 0:21:34.000 --> 0:21:37.560 with hexadecimal, you start at zero, you go up to nine, 0:21:37.760 --> 0:21:41.560 and then to fill in the additional digits you use 0:21:41.600 --> 0:21:45.639 a sequence like a B C d, E and F, so, 0:21:45.680 --> 0:21:48.600 in other words, and hexadecimal it goes zero to f 0:21:49.200 --> 0:21:53.480 before repeating. Each hexadecimal digit in this sequence of thirty 0:21:53.520 --> 0:21:58.160 two represents four bits, also known as a nibble. So 0:21:58.280 --> 0:22:01.679 while each decimal is and I p v for in 0:22:01.720 --> 0:22:05.800 an IPv for address represents an octet, each digit and 0:22:05.840 --> 0:22:09.600 a hexadecimal address represents a nibble. And now I'm not 0:22:09.640 --> 0:22:12.000 making any of that up. Four times thirty two is 0:22:12.080 --> 0:22:16.560 one eight, So that's where you get the one eight bits. 0:22:18.119 --> 0:22:20.920 What this means is that the effective number of addresses 0:22:21.400 --> 0:22:25.159 sky rockets. If none of the addresses were reserved for 0:22:25.240 --> 0:22:28.320 special use, you would have three point four times ten 0:22:28.400 --> 0:22:32.240 to the thirty eight power of addresses. So what is 0:22:32.280 --> 0:22:35.879 that in real numbers? I'd love to tell you, but 0:22:36.000 --> 0:22:39.080 the closest I can really get is three hundred forty 0:22:39.200 --> 0:22:43.000