1 00:00:08,930 --> 00:00:10,070 Welcome back. 2 00:00:10,100 --> 00:00:11,570 My name is David Bumble. 3 00:00:11,600 --> 00:00:12,560 C.S.I. 4 00:00:12,590 --> 00:00:14,210 11,023. 5 00:00:14,210 --> 00:00:16,850 And in this section, we're going to look at IP version six. 6 00:00:17,180 --> 00:00:22,550 We have been talking about the transition to IP version six for many years in the networking industry, 7 00:00:22,730 --> 00:00:25,010 but it looks like we finally run out of time. 8 00:00:25,490 --> 00:00:34,220 It looks like this is the final year, 2011, of being able to delay the transition to IPV six in production 9 00:00:34,220 --> 00:00:35,690 and real world environments. 10 00:00:35,990 --> 00:00:42,920 It's expected that in 2011 we will finally run out of IP version four addresses and be forced to move 11 00:00:42,920 --> 00:00:44,210 to IP version six. 12 00:00:44,630 --> 00:00:50,390 So it looks like we can no longer procrastinate the conversion of our networks to IP version six. 13 00:00:51,790 --> 00:00:54,210 But start with this news item from the BBC. 14 00:00:55,120 --> 00:01:02,080 Notice, dated 28 of January 2011, where they're talking about the lost big blocks of the nets, dwindling 15 00:01:02,080 --> 00:01:04,900 stock of addresses are about to be handed out. 16 00:01:05,319 --> 00:01:10,180 They're talking about total exhaustion in September 2011. 17 00:01:10,660 --> 00:01:17,230 However, notice what the Internet Corporation for Assigned Names and Numbers is stating on their website. 18 00:01:19,210 --> 00:01:22,360 Lost IPv4 addresses are allocated today. 19 00:01:22,480 --> 00:01:27,130 And I mean, you can read more about it on their website, but notice they say that today is a historic 20 00:01:27,130 --> 00:01:31,870 milestone for the Internet with a lost addresses have been allocated. 21 00:01:32,140 --> 00:01:38,080 So after years of rapid Internet expansion, the pool of available unallocated addresses for IP version 22 00:01:38,080 --> 00:01:40,360 four is completely depleted. 23 00:01:41,020 --> 00:01:45,280 Notice the news release February three, 2011. 24 00:01:45,430 --> 00:01:50,800 Available pool of unallocated IP version for internet addresses is now completely emptied. 25 00:01:51,860 --> 00:01:56,750 They talk about a critical point in history was reached today with allocation of the last remaining 26 00:01:56,750 --> 00:01:59,900 IP version for addresses from a central pool. 27 00:02:00,470 --> 00:02:04,460 So this is a major turning point in the ongoing development of the Internet. 28 00:02:04,970 --> 00:02:10,310 So notice you had two blocks of the dwindling IP version, four addresses, about 33 million of them 29 00:02:10,310 --> 00:02:14,300 were allocated earlier this week to the Asia Pacific region. 30 00:02:14,990 --> 00:02:20,750 When that happened, it meant the pool of IPv4 addresses had been depleted to a point where a global 31 00:02:20,750 --> 00:02:26,750 policy was triggered to immediately allocate the remaining small pool of addresses equally among the 32 00:02:26,750 --> 00:02:29,840 five global regional internet registries. 33 00:02:29,960 --> 00:02:31,520 This is now taken place. 34 00:02:32,200 --> 00:02:36,070 So they were allocated in a ceremony in Miami. 35 00:02:36,670 --> 00:02:41,290 So the procrastination for the convergence to IP version six is now finally over. 36 00:02:41,410 --> 00:02:47,470 We have to make sure we know how IP version six works and functions because we're going to come across 37 00:02:47,470 --> 00:02:50,530 it a lot more in the coming months and years. 38 00:02:51,070 --> 00:02:55,540 So what we're going to cover is firstly looking at the need for IP version six, and I think I've covered 39 00:02:55,540 --> 00:02:56,320 that already. 40 00:02:56,620 --> 00:03:02,470 We have run out of IP version for addresses and we are now forced to convert or migrate to IP version 41 00:03:02,470 --> 00:03:03,010 six. 42 00:03:03,490 --> 00:03:06,040 Going to explain the format of an IP version six address. 43 00:03:06,460 --> 00:03:10,060 An IP version six addresses 128 bits in length. 44 00:03:10,060 --> 00:03:15,700 So a lot larger than the 32 bit IP version for address that we used to working with. 45 00:03:16,030 --> 00:03:19,120 We can look at the methods of assigning an IP version six address. 46 00:03:19,480 --> 00:03:21,180 We can look at routing protocols. 47 00:03:21,190 --> 00:03:23,410 We can look at implementation strategies. 48 00:03:23,440 --> 00:03:26,560 And I'd like to show you a rip in G configuration. 49 00:03:26,710 --> 00:03:31,570 So in other words, I'll get a little network running using IP version six with RIP in G. 50 00:03:32,390 --> 00:03:37,040 The thing that seems to scare people most is the format of an IP version six address. 51 00:03:37,430 --> 00:03:42,680 The great thing about IP version six is you can take a lot of your knowledge of IP version four and 52 00:03:42,680 --> 00:03:44,660 just apply it in an IP version six. 53 00:03:44,660 --> 00:03:52,880 Environment routing protocols like OSPF, RIP, IP and so forth are available in IP version six. 54 00:03:53,120 --> 00:03:58,460 The version and the syntax might be slightly different, but a lot of the concepts remain the same. 55 00:03:58,730 --> 00:04:05,150 We still have TCP, IP and UDP and a lot of the other protocols, so you don't have to learn everything 56 00:04:05,150 --> 00:04:08,610 from scratch, which is a great benefit in IP. 57 00:04:08,630 --> 00:04:14,150 Vision for an address consists of four octets, which equals 32 bits in binary. 58 00:04:14,270 --> 00:04:20,209 So this is what an IP version for address would look like in binary or in dotted decimal notation. 59 00:04:20,660 --> 00:04:24,350 This is the number of IP addresses available in IP version four. 60 00:04:25,190 --> 00:04:26,900 Now an IP version six. 61 00:04:26,930 --> 00:04:31,850 The address is 16 octets in length, which equates to 128 bits. 62 00:04:32,000 --> 00:04:36,800 This is an IP version six address written in binary and as you can see, it's a lot, lot longer. 63 00:04:37,130 --> 00:04:43,700 IP version six addresses are typically written in hexadecimal, so this is the hex representation of 64 00:04:43,700 --> 00:04:45,860 this binary IPV six address. 65 00:04:46,250 --> 00:04:51,050 There are 3.4 times ten to the 38 IP addresses available. 66 00:04:51,320 --> 00:04:54,200 The pool is a much, much larger. 67 00:04:54,380 --> 00:05:00,170 The industry is learning from the mistakes of the past, and in this case they are making the pool very 68 00:05:00,170 --> 00:05:06,350 large so that we don't run into the same issue in a few years time where we run out of IP version six 69 00:05:06,350 --> 00:05:07,160 addresses. 70 00:05:07,280 --> 00:05:12,770 It's a dangerous thing to say this, but this should be enough addresses for future Internet growth 71 00:05:12,770 --> 00:05:13,730 requirements. 72 00:05:13,880 --> 00:05:20,570 But just to put this in perspective, there are enough IP version six addresses that we could allocate 73 00:05:20,570 --> 00:05:27,710 the entire equivalent IPV four Internet address space to every individual on Earth. 74 00:05:27,980 --> 00:05:30,230 That's how big this address space is. 75 00:05:31,380 --> 00:05:39,690 When comparing the Aussie model of IP version four to IP version six, you'll notice that all the layers 76 00:05:39,690 --> 00:05:45,960 except for layer three have remained the same or have only had slight modifications. 77 00:05:46,230 --> 00:05:53,100 So the application presentation session and transport will function in IP version six in the same way 78 00:05:53,100 --> 00:05:58,140 as they function an IP version for the network layers where the changes have been made. 79 00:05:58,140 --> 00:06:04,230 For instance, an IP version for Dres consists of only 32 bits, but an IPV six address consists of 80 00:06:04,230 --> 00:06:05,580 128 bits. 81 00:06:05,910 --> 00:06:10,140 The data link layer and physical layer also remain the same. 82 00:06:10,500 --> 00:06:15,390 So from a networking point of view, this is great news because you can take all your knowledge and 83 00:06:15,390 --> 00:06:20,880 experience of IP version four protocols and apply it in an IP version six environment. 84 00:06:21,090 --> 00:06:26,430 It's not like in other rooted protocols where you have to learn an entire new protocol stack. 85 00:06:26,700 --> 00:06:33,390 Protocols like TCP and UDP still remain at layer four and reside on top of IPV six, just like they 86 00:06:33,390 --> 00:06:34,740 do in IP version four. 87 00:06:35,710 --> 00:06:38,650 So let's look at the IPV six address format in more detail. 88 00:06:38,860 --> 00:06:46,870 It consists of eight X's where X is a 16 bit hexadecimal field separated by colons, so it would look 89 00:06:46,870 --> 00:06:48,040 something like this. 90 00:06:48,550 --> 00:06:56,320 Please note that an IPV six address is case insensitive, so you could write F in lowercase and b in 91 00:06:56,320 --> 00:06:58,790 uppercase and it wouldn't make any difference. 92 00:06:58,810 --> 00:07:00,490 It's not case sensitive. 93 00:07:00,820 --> 00:07:02,680 There are some rules that you need to remember. 94 00:07:02,920 --> 00:07:10,480 Leading zeros are optional within the 16 bit hexadecimal field, and successive fields of zeros can 95 00:07:10,480 --> 00:07:15,130 be represented as colon colon, but only once per dress. 96 00:07:15,400 --> 00:07:20,800 So as an example, you could take this address and rewrite it as the following. 97 00:07:22,000 --> 00:07:25,270 Notice these two octets could be written as a zero. 98 00:07:25,300 --> 00:07:27,640 And notice these four octets here. 99 00:07:27,760 --> 00:07:32,170 So the eight zeros in hexadecimal could be represented as colon. 100 00:07:32,170 --> 00:07:32,920 Colon. 101 00:07:33,220 --> 00:07:39,790 However, you cannot put colon colon twice within an IP address because the system would have no way 102 00:07:39,790 --> 00:07:43,690 of working out how many zeros are represented by these colons. 103 00:07:44,050 --> 00:07:50,530 Is this four zeros and this eight zeros, or is this eight zeros and this four zeros? 104 00:07:50,710 --> 00:07:54,130 So you can only put colon colon once in an address. 105 00:07:55,070 --> 00:07:55,400 Okay. 106 00:07:55,400 --> 00:07:56,750 Here's another example. 107 00:07:56,900 --> 00:08:03,650 We have an IP version six address written as follows Correct representations of this address would be 108 00:08:03,650 --> 00:08:06,590 as follows 2001 remains the same. 109 00:08:06,920 --> 00:08:09,830 This leading zero can be removed. 110 00:08:09,830 --> 00:08:11,330 So we have one, two, three. 111 00:08:11,960 --> 00:08:18,110 These four zeros and these four zeros can be condensed down to only colon. 112 00:08:18,110 --> 00:08:18,770 Colon. 113 00:08:18,950 --> 00:08:22,550 So those eight zeros can be compressed down to colon colon. 114 00:08:22,670 --> 00:08:24,860 The four F's remain the same. 115 00:08:25,190 --> 00:08:28,910 Now here you also have four zeros, followed by four zeros. 116 00:08:29,060 --> 00:08:33,770 However, you can only represent a string of zeros by colon. 117 00:08:33,770 --> 00:08:37,280 Colon once in an address, and you've already done that. 118 00:08:37,730 --> 00:08:41,270 So what you can do here is remove the leading zeros. 119 00:08:41,539 --> 00:08:46,970 And when you remove leading zeros, you have to have one value that remains between the colons. 120 00:08:47,120 --> 00:08:52,280 So notice here we've removed three leading zeros and here we've removed three leading zeros. 121 00:08:52,700 --> 00:08:56,690 Here we've removed the leading zero in front of ABC. 122 00:08:57,260 --> 00:08:59,150 So that zero has also been removed. 123 00:08:59,150 --> 00:09:01,940 So this is a correct representation of the address. 124 00:09:02,300 --> 00:09:09,290 Now you could do something similar where these eight zeros are represented by colon zero, colon zero, 125 00:09:09,530 --> 00:09:13,250 but these eight zeros are represented by Colon Colon. 126 00:09:13,490 --> 00:09:18,650 Remember, you can only have two colons written in this format once in an address. 127 00:09:19,220 --> 00:09:23,360 So this would be an incorrect format for an IPV six address. 128 00:09:23,840 --> 00:09:30,530 A writer will not accept you typing this address on an interface as it cannot work out how many zeros 129 00:09:30,530 --> 00:09:34,400 are between these two colons and how many zeros are between these two colons. 130 00:09:34,400 --> 00:09:37,970 You can only write colon colon once in an address. 131 00:09:38,570 --> 00:09:40,280 So here are some more examples. 132 00:09:40,490 --> 00:09:47,240 In this IPV six address, we have f01 followed by a bunch of zeros ending in a one. 133 00:09:47,660 --> 00:09:54,050 So we could represent that address by this or by this or by this. 134 00:09:54,080 --> 00:09:57,770 And I'm sure you can think of other variations of this address. 135 00:09:58,040 --> 00:10:00,860 Please note this is the same address. 136 00:10:00,860 --> 00:10:06,920 It's like saying to motto versus tomato or napkin versus Soviet. 137 00:10:07,250 --> 00:10:11,300 It's the same thing just represented in different formats. 138 00:10:11,900 --> 00:10:13,310 He has another example. 139 00:10:13,760 --> 00:10:18,260 We've got four ones followed by one, two, three, four, followed by eight zeros followed by one, 140 00:10:18,260 --> 00:10:22,010 two, three, four, followed by eight zeros followed by four ones. 141 00:10:22,490 --> 00:10:25,550 These four zeros can be condensed down to zero. 142 00:10:25,880 --> 00:10:28,520 These four zeros can be condensed down to zero. 143 00:10:28,940 --> 00:10:32,150 And these eight zeros can be condensed down to colon. 144 00:10:32,150 --> 00:10:32,810 Colon. 145 00:10:33,410 --> 00:10:37,070 Or you can say those eight zeros are represented by colon colon. 146 00:10:37,610 --> 00:10:43,430 And these four zeros by a zero and those four zeros by a zero. 147 00:10:43,520 --> 00:10:49,340 Once again, it's the same address, different representations, whichever you prefer. 148 00:10:49,910 --> 00:10:54,590 Once again, this address, a bunch of zeros followed by one, could be represented as colon. 149 00:10:54,590 --> 00:10:55,400 Colon one. 150 00:10:55,850 --> 00:11:01,610 This is the loopback address of an interface, and a string of zeros could be represented as colon. 151 00:11:01,610 --> 00:11:02,210 Colon. 152 00:11:02,210 --> 00:11:04,610 This is an example of an unassigned address. 153 00:11:05,000 --> 00:11:06,710 So I'm on a Windows machine. 154 00:11:06,710 --> 00:11:12,020 I could ping 120 7001 the loopback in IP version four. 155 00:11:12,960 --> 00:11:19,110 By the same token, I can pin colon colon one, which is the loopback in IP version six. 156 00:11:19,770 --> 00:11:26,940 If you remember, the designers of IP version four unfortunately chose a class address for the loopback 157 00:11:26,940 --> 00:11:33,510 address and thus the IP version for address range lost 60 million host addresses because the loopback 158 00:11:33,510 --> 00:11:36,430 is a class A address in IPV six. 159 00:11:36,450 --> 00:11:40,770 The designers have tried to avoid the same mistakes that were made in the past. 160 00:11:40,890 --> 00:11:43,350 So notice the loopback address here is just colon. 161 00:11:43,350 --> 00:11:44,220 Colon one. 162 00:11:44,910 --> 00:11:46,440 But I could also ping. 163 00:11:54,050 --> 00:11:56,900 Which is the same address the loopback. 164 00:11:57,140 --> 00:11:58,880 Or I could do the following. 165 00:12:04,890 --> 00:12:06,150 Or something like this. 166 00:12:11,870 --> 00:12:14,000 Notice it's all the same address. 167 00:12:14,090 --> 00:12:20,270 My PC automatically converts it into colon colon one, which I think is the easiest representation of 168 00:12:20,270 --> 00:12:21,140 this address. 169 00:12:22,110 --> 00:12:24,240 Now in the real world, this is going to be a lot of fun. 170 00:12:24,570 --> 00:12:30,150 It's difficult enough trying to get users to type HTTP, colon, forward slash, forward slash and IP 171 00:12:30,150 --> 00:12:32,820 version for address into a web browser. 172 00:12:33,120 --> 00:12:37,080 Now, can you imagine trying to get them to do the following in IP version six? 173 00:12:37,080 --> 00:12:43,150 In a web browser, you have to enclose the IP address within square brackets as follows. 174 00:12:43,170 --> 00:12:49,740 So in other words, you would type HTTP colon forward, slash forward, slash the IP version six, address 175 00:12:49,740 --> 00:12:50,790 colon. 176 00:12:50,790 --> 00:12:55,980 And then for instance, the port number, let's say 80, 80, and then for instance, a file name, 177 00:12:55,980 --> 00:12:57,870 let's say indexed HTML. 178 00:12:58,440 --> 00:13:01,020 This is obviously going to be very difficult for users. 179 00:13:01,200 --> 00:13:04,590 So I suppose you would use this mostly for diagnostic purposes. 180 00:13:04,860 --> 00:13:08,080 But I can see that we're going to have to ask users to do this at some point. 181 00:13:08,100 --> 00:13:09,480 So good luck with that. 182 00:13:09,690 --> 00:13:14,130 So it's recommended to use fully qualified domain names rather than IP addresses. 183 00:13:14,130 --> 00:13:19,770 So rather than typing something like this, you would say Cisco dot com and then rely on DNS to do the 184 00:13:19,770 --> 00:13:20,610 conversion. 185 00:13:21,150 --> 00:13:27,960 Now to test your IP version six connectivity, you can go to this website, HTTP forge slash forward 186 00:13:27,960 --> 00:13:35,460 slash test IPV six dot com and this will run a series of tests to check your connectivity to IP version 187 00:13:35,460 --> 00:13:36,030 six. 188 00:13:36,930 --> 00:13:40,830 As you can see, I'm going to have a problem where I'm currently residing. 189 00:13:42,410 --> 00:13:47,480 Is also information about IPv6 Day, which, depending on when you're viewing this, may have taken 190 00:13:47,480 --> 00:13:48,410 place already. 191 00:13:48,800 --> 00:13:55,100 It's scheduled for eight of June 2011, when there's going to be a global scale test flight of IP version 192 00:13:55,100 --> 00:13:55,730 six. 193 00:13:56,090 --> 00:13:56,840 It's a major Web. 194 00:13:56,840 --> 00:14:03,290 Companies and other industry players will enable IP version six on their main websites for 24 hours. 195 00:14:04,490 --> 00:14:09,330 Now the different types of addresses in IP version six, some of which you'll recognize already. 196 00:14:09,350 --> 00:14:14,810 The first one is a unicast address, which is an address allocated to a single interface, for example. 197 00:14:15,170 --> 00:14:19,940 There are several types of unicast addresses and I'll go through all of these in more detail in the 198 00:14:19,940 --> 00:14:21,110 upcoming slides. 199 00:14:21,440 --> 00:14:24,560 But firstly, you have a global unicast address. 200 00:14:24,590 --> 00:14:28,400 There is no need for net in IP version six. 201 00:14:28,610 --> 00:14:30,620 That comes as a big shock to a lot of people. 202 00:14:30,620 --> 00:14:34,820 Remember net was introduced to try and conserve IP version for addresses. 203 00:14:35,210 --> 00:14:38,870 Yeah, we have plenty of addresses, so there's no need for net. 204 00:14:38,960 --> 00:14:44,150 A lot of people say that that's a security vulnerability, but remember that net or network address 205 00:14:44,150 --> 00:14:47,330 translation was not developed for security originally. 206 00:14:47,330 --> 00:14:49,280 That's a byproduct of net. 207 00:14:49,520 --> 00:14:53,010 Yeah, we have globally unique unicast addresses. 208 00:14:53,030 --> 00:14:59,240 The address on your interface, on your PC at home will be unique globally. 209 00:14:59,540 --> 00:15:04,250 There is no need for your IP address to be netted to an external or public address. 210 00:15:04,700 --> 00:15:10,340 There are enough public, if you like, global unicast addresses available for all devices in the world. 211 00:15:10,520 --> 00:15:14,120 There are also reserved unicast addresses and we won't worry too much about them. 212 00:15:14,330 --> 00:15:20,180 We also have link local unicast addresses and only refer to a particular physical link. 213 00:15:20,270 --> 00:15:23,120 Routers do not forward link local addresses. 214 00:15:23,300 --> 00:15:23,630 Link. 215 00:15:23,630 --> 00:15:29,210 Local addresses will allow two hosts to communicate with each other without IP addresses being assigned 216 00:15:29,210 --> 00:15:30,290 to those devices. 217 00:15:30,290 --> 00:15:35,660 So two users could connect their PCs back to back using, for instance, a crossover cable, and they'll 218 00:15:35,660 --> 00:15:42,560 have immediate IP connectivity without the need for manual configuration of addresses or for a DHCP 219 00:15:42,560 --> 00:15:43,190 server. 220 00:15:43,520 --> 00:15:48,530 Many IPV six routing protocols also use link local addresses to communicate with each other. 221 00:15:48,980 --> 00:15:54,020 Link Local addresses are also used for link communication such as automatic address configuration, 222 00:15:54,020 --> 00:15:56,570 neighbor discovery and router discovery. 223 00:15:56,870 --> 00:15:59,540 I'll show you what a link local address looks like in a moment. 224 00:15:59,780 --> 00:16:06,440 We also have site local unicast addresses, which are similar in concept to RFC 1918 private addresses. 225 00:16:06,770 --> 00:16:11,000 These are addresses assigned to an entire site within an organization. 226 00:16:11,360 --> 00:16:18,110 So a site local address would only be valid within the site network of an organization so that local 227 00:16:18,110 --> 00:16:23,270 addresses were part of the original addressing architecture from 1995. 228 00:16:23,450 --> 00:16:31,090 But please note that site local unicast addresses have been deprecated since September 2004. 229 00:16:31,100 --> 00:16:37,670 And you can go to read more about this in or of C three, eight, seven, nine where they talk about 230 00:16:37,670 --> 00:16:39,710 deprecating site local addresses. 231 00:16:40,160 --> 00:16:46,040 It's important to note that the development of IPV six has been ongoing for a number of years, and 232 00:16:46,040 --> 00:16:51,380 certain terms that you come across, such as site local addresses, will have changed or been updated 233 00:16:51,380 --> 00:16:53,090 or in this case, deprecated. 234 00:16:53,330 --> 00:16:59,990 So they no longer used because of the confusion and ambiguity of the term site, they have now been 235 00:16:59,990 --> 00:17:03,080 replaced with what are called unique local addresses. 236 00:17:03,650 --> 00:17:08,630 There also some special purpose unicast addresses such as unspecified, which have already shown you 237 00:17:08,630 --> 00:17:09,589 it's just colon. 238 00:17:09,589 --> 00:17:16,550 Colon and is used to refer to the host itself and is used when a device does not know its own IP address. 239 00:17:16,880 --> 00:17:22,520 This would be typically used in the source field of a datagram that is sent by a device that seeks to 240 00:17:22,520 --> 00:17:24,260 have its IP address configured. 241 00:17:24,560 --> 00:17:25,310 So colon. 242 00:17:25,310 --> 00:17:26,990 Colon means unspecified. 243 00:17:27,170 --> 00:17:28,910 I've already demonstrated loopback. 244 00:17:28,940 --> 00:17:29,690 That would be colon. 245 00:17:29,690 --> 00:17:34,850 Colon one which is very similar to 120 7001, for example. 246 00:17:35,090 --> 00:17:39,350 Now IP version for compatible addresses have also been deprecated. 247 00:17:39,410 --> 00:17:45,110 It would allow for the representation of an IP version for address within IP version six. 248 00:17:45,230 --> 00:17:52,130 The most significant 96 bits of the address would be set to zero, while the lot 32 bits of the IP version 249 00:17:52,130 --> 00:17:53,810 for address that is represented. 250 00:17:54,230 --> 00:17:56,510 This was deprecated in 2006. 251 00:17:57,020 --> 00:18:02,240 The reason I still mention these addresses is that you may come across them in IP version six literature. 252 00:18:02,510 --> 00:18:03,290 Just be aware. 253 00:18:03,320 --> 00:18:08,510 Like a lot of things in life, changes have taken place and certain technologies and addresses have 254 00:18:08,510 --> 00:18:10,400 been dropped or deprecated. 255 00:18:10,700 --> 00:18:15,080 So be aware the first type of address and IP version six is unicast. 256 00:18:15,950 --> 00:18:22,910 The second is multicast, where one host speaks to many hosts, and this is very similar to multicast 257 00:18:23,000 --> 00:18:29,450 and IP version four because it enables more efficient use of the network but uses a longer address range. 258 00:18:29,750 --> 00:18:36,290 The advantage of multi costing is that a single stream from a single server can go to many, many devices. 259 00:18:36,380 --> 00:18:42,710 So 100 devices could be receiving the same video stream of one megabits per second rather than having 260 00:18:42,710 --> 00:18:48,350 101 megabits per second streams and thus using up 100 megabits per second. 261 00:18:48,380 --> 00:18:52,020 If unicast was used, the third type is any cost. 262 00:18:52,040 --> 00:18:55,220 Now this does exist in IP version four as well. 263 00:18:55,520 --> 00:19:02,450 This is known as one to nearest unicast addresses are used, but the same address is configured on two 264 00:19:02,450 --> 00:19:03,800 or more devices. 265 00:19:04,010 --> 00:19:08,900 The idea here is that routers will decide on the closest device to reach the destination. 266 00:19:09,020 --> 00:19:14,870 If you are going to Amazon.com, for example, you wouldn't care if that server was hosted in California 267 00:19:14,870 --> 00:19:16,130 or in New York. 268 00:19:16,430 --> 00:19:19,760 You just want to purchase a book, for example, from Amazon. 269 00:19:20,000 --> 00:19:26,180 If you are on the West Coast of the US, you would be closer to a server in California than you would 270 00:19:26,180 --> 00:19:27,830 be to a server in New York. 271 00:19:27,950 --> 00:19:33,710 So with any cost to servers, one in New York, one in San Francisco, for example, are configured 272 00:19:33,710 --> 00:19:35,180 with the same IP address. 273 00:19:35,360 --> 00:19:41,270 If you're on the West Coast of the US and you are going to Amazon.com, for example, you would be routed 274 00:19:41,270 --> 00:19:47,090 to the server in San Francisco because it's physically closer to you than the server in New York. 275 00:19:47,360 --> 00:19:52,850 By the same token, if you're on the East Coast, you'd be routed to the server in New York. 276 00:19:52,880 --> 00:19:55,940 It allows for load balancing and content delivery services. 277 00:19:56,150 --> 00:19:59,060 As I've mentioned, it already exists in IP version four. 278 00:19:59,180 --> 00:20:02,350 So there are three address types in IP version six. 279 00:20:02,390 --> 00:20:06,830 So we are broadcasts which are so common in IP version four broadcasts. 280 00:20:06,830 --> 00:20:08,360 Addresses no longer exist. 281 00:20:08,750 --> 00:20:16,220 Broadcasts can cause lots of issues on networks, and broadcasting has been replaced with multi costing 282 00:20:16,220 --> 00:20:18,170 in an IP version six environment. 283 00:20:18,290 --> 00:20:23,340 We no longer send broadcasts if we want to contact multiple devices. 284 00:20:23,360 --> 00:20:26,600 We send a multicast instead of a broadcast. 285 00:20:27,600 --> 00:20:32,340 Now, as mentioned, an IP version six address is 128 bits in length. 286 00:20:32,550 --> 00:20:34,470 It consists of two main portions. 287 00:20:34,470 --> 00:20:40,950 We have the network portion or network prefix and the interface identifier or host portion. 288 00:20:41,220 --> 00:20:43,920 Each of these is 64 bits in length. 289 00:20:44,130 --> 00:20:49,890 Now, it may come as a surprise to you, but there's no subletting an IP version six like an IP version 290 00:20:49,890 --> 00:20:56,190 for we're not going to subnet to say a slash 30 or slash 28 or slash 16. 291 00:20:56,520 --> 00:21:02,880 We're not going to have classes of addresses like class A, B and C and subnets of those, like taking 292 00:21:02,880 --> 00:21:06,450 a Class C address and submitting it to slash 28 or slash 30. 293 00:21:06,750 --> 00:21:08,760 That no longer exists. 294 00:21:08,790 --> 00:21:11,400 The following statement is important to understand. 295 00:21:11,550 --> 00:21:18,020 Every interface has a mask of slash 64 in your enterprise environments. 296 00:21:18,030 --> 00:21:23,520 Every interface when using a unicast address has a mosque of slash 64. 297 00:21:24,090 --> 00:21:25,200 I'll say that again. 298 00:21:25,200 --> 00:21:28,950 All interfaces have a subnet mask of slash 64. 299 00:21:29,340 --> 00:21:32,880 In other words, the network prefix is always slash 64. 300 00:21:32,910 --> 00:21:37,560 In our enterprise environment, the host portion is always 64 bits. 301 00:21:37,830 --> 00:21:43,010 So this actually makes our lives a lot easier because we don't have to do crazy sub netting in IP version 302 00:21:43,020 --> 00:21:46,380 six in a similar way to we had to do an IP version four. 303 00:21:46,770 --> 00:21:49,440 So there's no subnet like an IP version four. 304 00:21:49,470 --> 00:21:54,990 There's also no net like an IP version for NAT is no longer required. 305 00:21:55,970 --> 00:22:02,750 Addresses an organization's use what are called aggregate able global unicast addresses, which is quite 306 00:22:02,750 --> 00:22:03,620 a mouthful. 307 00:22:03,740 --> 00:22:06,680 I'll just refer to these as global unicast addresses. 308 00:22:06,800 --> 00:22:11,660 But the full name once again is aggregate all global unit cost addresses. 309 00:22:11,690 --> 00:22:15,750 In other words, addresses within your organization are globally unique. 310 00:22:15,770 --> 00:22:22,070 There is no need to net those addresses when going on to the internet because they are like public IP 311 00:22:22,070 --> 00:22:23,950 addresses within organizations. 312 00:22:23,960 --> 00:22:25,520 They are globally unique. 313 00:22:25,760 --> 00:22:27,650 There also unicast addresses. 314 00:22:27,920 --> 00:22:34,100 The term aggregate able means that they can be aggregated or summarized in the global internet. 315 00:22:34,280 --> 00:22:41,330 The designers of IP version six have specifically looked at aggregation of addresses to reduce routing 316 00:22:41,360 --> 00:22:44,000 table sizes within the global Internet. 317 00:22:44,370 --> 00:22:46,370 Now, I'll show you an example of that in a moment. 318 00:22:46,970 --> 00:22:51,410 Each link or interface will have a slash 64 subnet mask. 319 00:22:51,620 --> 00:22:53,870 Once again, this makes life a lot easier. 320 00:22:54,200 --> 00:23:03,140 The interface identifier or ID, which is 64 bits in length, can use a modified UI 64 format address, 321 00:23:03,140 --> 00:23:05,270 which I'll explain in a moment. 322 00:23:05,510 --> 00:23:11,580 But it's essentially a modified Mac address for those of you who've been in networking for a long time. 323 00:23:11,600 --> 00:23:18,620 You may remember how IP also use the Mac address and that same thinking can be used in IP version six. 324 00:23:19,190 --> 00:23:25,280 So the UI address allows us to get the interface ID portion of an IP version six address. 325 00:23:25,430 --> 00:23:31,100 This can be used in multiple IP version six addresses, including linked local site, local as well 326 00:23:31,100 --> 00:23:33,980 as the stateless order configuration mechanism. 327 00:23:34,430 --> 00:23:36,260 Don't worry too much about those now. 328 00:23:36,410 --> 00:23:38,390 I'll be talking about them in a moment. 329 00:23:38,390 --> 00:23:44,180 But please note an IP address can also be used in an aggregated global unicast address. 330 00:23:44,330 --> 00:23:50,780 It doesn't have to be, but you can use it if you so desire and you just set that with a command on 331 00:23:50,780 --> 00:23:51,770 a Cisco router. 332 00:23:52,010 --> 00:23:58,010 So what happens is the router or other device takes its Ethernet MAC address, which is 48 bits in length. 333 00:23:58,370 --> 00:24:01,160 And here's an example of an Ethernet MAC address. 334 00:24:01,550 --> 00:24:07,340 And the address is split in half between the vendor portion and the unique portion of the MAC address. 335 00:24:07,640 --> 00:24:14,480 F f e is inserted in the middle, which results in a 64 bit address. 336 00:24:14,660 --> 00:24:17,510 Remember all of these values on hexadecimal? 337 00:24:17,510 --> 00:24:20,210 So this represents 64 bits. 338 00:24:21,710 --> 00:24:29,000 So again, please note that this address is written in hexadecimal because IP version six addresses 339 00:24:29,030 --> 00:24:30,590 are written in hexadecimal. 340 00:24:31,860 --> 00:24:36,150 These two hexadecimal values equate to eight binary bits.