1 00:00:01,140 --> 00:00:04,820 In this video we're going to look at IP version for tracing. 2 00:00:04,920 --> 00:00:10,380 I'm going to give you an overview of IP version 4 addresses and explain the basics of provision for 3 00:00:10,380 --> 00:00:11,310 addressing. 4 00:00:11,370 --> 00:00:18,630 From now on I'm going to refer to IP addresses but be a way of please that I'm discussing IP version 5 00:00:18,630 --> 00:00:23,250 4 addresses in this video and not IP version 6 addresses. 6 00:00:23,250 --> 00:00:29,710 We're going to look at an overview of IP addresses what they looked like and how they function. 7 00:00:29,730 --> 00:00:34,670 I'm going to explain the various address classes that you get an IP version 4. 8 00:00:34,680 --> 00:00:40,000 In other words plus A plus B plus C plus D and Class E. 9 00:00:40,170 --> 00:00:41,750 We'll also talk about cyder. 10 00:00:41,850 --> 00:00:46,030 We'll see IDR and how that changes the address classes. 11 00:00:46,190 --> 00:00:53,130 But as a foundation it's important that you understand the 5 address classes A B C D and he will look 12 00:00:53,130 --> 00:00:59,310 at special IP addresses including the loopback address the local broadcast address and other special 13 00:00:59,310 --> 00:01:00,160 addresses. 14 00:01:00,360 --> 00:01:07,800 And lastly I'm going to explain what network mosques do and why they important with regards to IP addressing. 15 00:01:07,830 --> 00:01:15,560 So what is an IP address an IP address is a layer 3 logical address assigned by an administrator. 16 00:01:15,810 --> 00:01:22,380 Unlike MAC addresses which are hard coded or burnt into Network Interface Cards by the manufacturer 17 00:01:22,770 --> 00:01:25,500 an IP address is configured by an administrator. 18 00:01:25,500 --> 00:01:29,160 The IP address may change within a subnet. 19 00:01:29,160 --> 00:01:36,620 For example when using DHP or Dynamic Host Configuration Protocol an IP address resides at a layer 3 20 00:01:36,630 --> 00:01:38,250 in the overside model. 21 00:01:38,250 --> 00:01:43,590 Please refer to the oocyte videos for more details on how the overside model works. 22 00:01:43,650 --> 00:01:50,370 An IP address is used to uniquely identify a device on the network and is used by routers to determine 23 00:01:50,370 --> 00:01:52,770 where that device is. 24 00:01:52,770 --> 00:02:01,500 So a router routes traffic to a destination IP address based on a hierarchy of network and host which 25 00:02:01,500 --> 00:02:03,480 will talk about in a moment. 26 00:02:03,480 --> 00:02:10,950 So once again the IP address uniquely identifies a device in a network in a similar way to how houses 27 00:02:11,370 --> 00:02:17,300 are uniquely identified him Street houses in the street have a unique address. 28 00:02:17,310 --> 00:02:26,160 So for example 10 Oxford Street in the same way a host in a network has a unique identifier on that 29 00:02:26,160 --> 00:02:28,650 network being its IP address. 30 00:02:28,650 --> 00:02:31,970 I'm going to expand on that analogy in the next few minutes. 31 00:02:32,100 --> 00:02:36,090 Every device on Internet has a unique IP address. 32 00:02:36,090 --> 00:02:39,630 So they are millions of IP addresses out there. 33 00:02:39,840 --> 00:02:44,790 And no two devices can have the same IP address for communication on the Internet. 34 00:02:44,820 --> 00:02:52,980 Every device needs a unique IP address and hence the move to IP version 6 these days because of IP version 35 00:02:52,980 --> 00:02:54,780 4 address exhaustion. 36 00:02:54,780 --> 00:03:01,740 So for example you cannot have a device 10 dot 1.1 but one communicating with a another device with 37 00:03:01,740 --> 00:03:05,920 the same IP address that's going to cause a conflict in the network. 38 00:03:05,970 --> 00:03:13,440 Every device on the Internet has its own unique IP address and requires a unique IP address for communication. 39 00:03:13,440 --> 00:03:22,270 Now I will be talking about RAFC 1918 addresses in a moment in that RAFC private IP address as I explained. 40 00:03:22,380 --> 00:03:31,150 So tender at 1.1 that one is an example of a private IP address as specified in our FC 19:18 you know 41 00:03:31,160 --> 00:03:38,010 a lot of organizations today private IP addresses are used internally and then those addresses on nattered 42 00:03:38,180 --> 00:03:41,870 or network address translated onto the Internet. 43 00:03:41,880 --> 00:03:49,410 So when a device with IP address 10 1 1 1 is connected to a public IP address such as 12 to one that 44 00:03:49,480 --> 00:03:57,890 1.1 the public IP address in this case 12 the one at one time one needs to be unique on the Internet. 45 00:03:57,990 --> 00:04:04,200 For now just understand that IP address is on the internet need to be unique from each other network 46 00:04:04,200 --> 00:04:08,050 address translation or Knecht once again is not covered in this video. 47 00:04:08,160 --> 00:04:12,930 But I will be discussing that in the set of CCMA videos. 48 00:04:12,930 --> 00:04:20,430 So be aware that in the real world multiple companies may use my IP address to send out one but one 49 00:04:20,460 --> 00:04:25,280 at one but those addresses are not tied to unique IP addresses. 50 00:04:25,320 --> 00:04:28,900 When those devices in traffic onto the Internet. 51 00:04:29,030 --> 00:04:33,560 Now here's a quick demonstration of some IP addresses. 52 00:04:33,560 --> 00:04:37,430 If I'm paying w w w dot yahoo dot com. 53 00:04:37,460 --> 00:04:41,970 Notice that the domain name is translated to an IP address. 54 00:04:41,990 --> 00:04:50,540 So in this case yahoo dot com is translated by a protocol called DNS or Domain Name Service to an IP 55 00:04:50,540 --> 00:04:56,370 address of 87 dot 2:48 dot 112 dot 181. 56 00:04:56,480 --> 00:05:02,540 DNS is used to convert easy to read names to IP addresses. 57 00:05:02,570 --> 00:05:09,790 It's much easier to remember a simple name such as Yahoo dot com or Cisco dot com or BBC. 58 00:05:09,810 --> 00:05:16,410 It's here to UK rather than having to remember the IP address of those domain names. 59 00:05:16,700 --> 00:05:23,450 As an analogy this is similar to a phone book where we are translating human friendly computer names 60 00:05:23,660 --> 00:05:25,100 to IP addresses. 61 00:05:25,340 --> 00:05:32,090 But what I'd like you to notice is that the IP address of yahoo dot com was resolved and we got an IP 62 00:05:32,090 --> 00:05:36,490 address of 87 to 4 8 1 1 2 181. 63 00:05:36,650 --> 00:05:40,100 I could pick another web site such as HP dot com. 64 00:05:40,100 --> 00:05:47,160 Notice the IP address is translated to 15 from 192 45 139. 65 00:05:47,210 --> 00:05:52,160 Now a lot of Web sites don't permit pings which uses ICMP. 66 00:05:52,370 --> 00:05:54,860 So the request times out. 67 00:05:55,040 --> 00:06:01,540 But notice that the DNS server did resolve HP to come to a 15 address. 68 00:06:01,790 --> 00:06:05,210 Now in a moment I'm going to explain what class A addresses are. 69 00:06:05,360 --> 00:06:14,780 But for this example HP own the 15 class a public address range so anything that starts with 15 in the 70 00:06:14,780 --> 00:06:17,370 first octet belongs to HP. 71 00:06:17,570 --> 00:06:25,670 Here's another example a pink Google dot com notice in this case it resolves to 74 125 233 50.