1 00:00:01,589 --> 00:00:05,370 Now what is in a V NFI or network functions? 2 00:00:05,370 --> 00:00:11,970 Virtualization is the idea that you've virtualized network devices and network functions. 3 00:00:12,360 --> 00:00:17,820 He has a document explaining and a V and it's very good if you're interested in getting into the details. 4 00:00:18,500 --> 00:00:20,210 This is from the. 5 00:00:21,040 --> 00:00:25,000 SD in an open flow World Congress in 2012. 6 00:00:25,360 --> 00:00:29,170 But you don't need to spend a lot of time going through this document. 7 00:00:29,170 --> 00:00:30,550 That's only of interest. 8 00:00:31,390 --> 00:00:35,500 I'll explain briefly what NFI is for the CNA exam. 9 00:00:36,470 --> 00:00:38,720 Service have been virtualized for years. 10 00:00:38,960 --> 00:00:42,920 So as an example, here I'm running a Cisco core manager. 11 00:00:45,280 --> 00:00:48,550 As a virtual machine in Essex, I. 12 00:00:49,470 --> 00:00:55,980 And I couldn't connect to that server as an example using a web browser and then configure the server. 13 00:00:56,770 --> 00:01:03,040 Servers are now virtualized in the cloud, and I can spin up instances of servers very, very quickly 14 00:01:03,040 --> 00:01:09,730 using Amazon EC2 or Microsoft Azure or the Google Cloud. 15 00:01:10,730 --> 00:01:18,080 The networking, however, has generally in the past sold physical boxes for functions. 16 00:01:18,440 --> 00:01:24,590 So in other words, if you wanted a firewall, you would buy a physical piece of hardware that provides 17 00:01:24,590 --> 00:01:27,550 a function or a set of functions to you. 18 00:01:27,560 --> 00:01:28,910 In this case, firewall. 19 00:01:30,020 --> 00:01:37,820 If you wanted a VPN device in the past, you would buy a VPN concentrator or a device dedicated to creating 20 00:01:37,820 --> 00:01:39,200 VPN connections. 21 00:01:39,880 --> 00:01:46,930 In the past, if you wanted a load balancer, you would buy a physical load balancer or a session border 22 00:01:46,930 --> 00:01:47,650 controller. 23 00:01:47,650 --> 00:01:50,350 You would buy a physical device for that function. 24 00:01:51,010 --> 00:01:55,150 Rudders such as a piranha are physical devices. 25 00:01:55,150 --> 00:01:57,730 If you want a router, you would buy a physical rudder. 26 00:01:58,120 --> 00:02:06,490 Now the idea with network virtualization is we virtualize network devices in the same way that we virtualized 27 00:02:06,490 --> 00:02:07,300 servers. 28 00:02:07,900 --> 00:02:15,190 So we take these physical devices and we run them as a virtual appliances on physical servers. 29 00:02:15,700 --> 00:02:18,580 And he has an example once again of doing that. 30 00:02:18,580 --> 00:02:28,510 I've got a single physical server running iSCSI, but here I've got multiple Cisco CSR routers running. 31 00:02:29,670 --> 00:02:31,500 As a virtual machines. 32 00:02:33,280 --> 00:02:37,510 In Essex if I use the command show ip ospf neighbor. 33 00:02:38,600 --> 00:02:41,180 Notice I see multiple neighbor relationships. 34 00:02:42,070 --> 00:02:46,800 So this device, 19216812 or three is a physical router. 35 00:02:46,810 --> 00:02:52,720 So what I'll do is telnet to that physical router and I'll log in. 36 00:02:52,990 --> 00:03:00,760 Notice this is an 1841, so show version shows me that this is an 1841 physical router show. 37 00:03:00,760 --> 00:03:09,220 Diag, as an example, shows me the physical components in that router, but back on the iSCSI router 38 00:03:09,340 --> 00:03:15,310 show version shows me that this is a CSR rather show diag. 39 00:03:18,470 --> 00:03:20,720 It doesn't show the same information. 40 00:03:28,360 --> 00:03:32,290 Because this is a virtual router, not a physical router. 41 00:03:32,710 --> 00:03:39,910 You can see as an example that it's a CSR 1000 ve so show ip ospf neighbor once again shows me different 42 00:03:39,910 --> 00:03:44,620 neighbor relationships and I could telnet to another router. 43 00:03:48,200 --> 00:03:52,250 This Rada is a 1941. 44 00:03:52,550 --> 00:03:54,590 So this is another physical Rada. 45 00:03:55,880 --> 00:04:01,400 So what's the point rather than running physical rotters? 46 00:04:02,880 --> 00:04:10,500 Why not run multiple virtual routers in the same way that you run the virtual servers? 47 00:04:11,280 --> 00:04:18,510 The concept of having a physical device for every function doesn't make sense in today's world. 48 00:04:19,260 --> 00:04:24,160 As I demonstrated, it only takes a few minutes to spin up a virtual machine. 49 00:04:24,180 --> 00:04:30,720 On Amazon, it's been easy in the past to spin up virtual servers and allocate a virtual disk space 50 00:04:30,720 --> 00:04:31,620 or storage. 51 00:04:32,160 --> 00:04:38,280 But one of the big problems in the past has been that networking required physical devices. 52 00:04:38,880 --> 00:04:46,770 So just like years ago, server administrators no longer have a physical server per application, such 53 00:04:46,770 --> 00:04:49,230 as email or web services. 54 00:04:49,740 --> 00:04:54,150 We now in networking don't have a physical device. 55 00:04:54,820 --> 00:05:05,380 For a physical function, we can run virtual routers and virtual firewalls as virtual machines alongside 56 00:05:05,380 --> 00:05:06,820 our virtual servers. 57 00:05:07,590 --> 00:05:14,010 One of the advantages of doing that as an example is you could run a virtual firewall in front of every 58 00:05:14,010 --> 00:05:16,740 virtual server if you needed to. 59 00:05:16,770 --> 00:05:23,970 You can implement what's called micro segmentation, where you segment your network down into tiny subnets 60 00:05:23,970 --> 00:05:30,810 or tiny segments to reduce broadcasts to implement better security and other benefits. 61 00:05:31,290 --> 00:05:37,620 It doesn't make sense today to have a physical network device for every function. 62 00:05:37,650 --> 00:05:44,130 If you have the requirement for a firewall, it doesn't make sense to buy a physical firewall for your 63 00:05:44,130 --> 00:05:45,150 virtual servers. 64 00:05:45,180 --> 00:05:52,170 In some cases, it makes sense to buy a virtual firewall that you run on the same hypervisor as your 65 00:05:52,170 --> 00:05:53,280 virtual servers. 66 00:05:53,970 --> 00:05:56,980 So this is the idea of network function virtualization. 67 00:05:57,000 --> 00:06:04,440 We firstly virtualize an appliance such as a router or a firewall or a load balancer, but then taking 68 00:06:04,440 --> 00:06:08,520 it a step further, we can also load balance functions. 69 00:06:08,910 --> 00:06:15,900 So if all you need is to implement something such as DRP or HSP, it doesn't make sense to run a full 70 00:06:15,900 --> 00:06:18,810 operating system in the server world. 71 00:06:18,810 --> 00:06:26,310 We have the concept of Docker and the same kind of idea is now starting to happen in networking where 72 00:06:26,310 --> 00:06:29,880 we just run functions rather than entire operating systems. 73 00:06:30,420 --> 00:06:33,220 I've added some videos about Docker to the course. 74 00:06:33,240 --> 00:06:37,710 They are only of interest and are not part of the CCNA exam. 75 00:06:38,160 --> 00:06:42,780 So if you're interested in learning some real world stuff about Docker and newer technologies, have 76 00:06:42,780 --> 00:06:43,980 a look at those videos.