1 00:00:05,200 --> 00:00:05,920 Now some good news. 2 00:00:05,920 --> 00:00:12,970 Before we get into the network automation section you don't have to learn python for the CCMA exam that's 3 00:00:12,970 --> 00:00:16,410 covered in the Cisco definite certification. 4 00:00:16,450 --> 00:00:20,650 I took the CCMA and definite associate exam on the same day. 5 00:00:20,650 --> 00:00:26,980 I've spoken previously about this early in the course but I'm going to replay parts of that video in 6 00:00:26,980 --> 00:00:30,180 this section just to remind you of my thoughts. 7 00:00:30,190 --> 00:00:38,230 When I took the exam the CCMA examined testing on topics such as REST API Jason formatting that's covered 8 00:00:38,620 --> 00:00:43,990 in the automation and program ability section of the blueprint. 9 00:00:43,990 --> 00:00:48,730 So as an example make sure that you know how to interpret Jason encoded data. 10 00:00:48,760 --> 00:00:56,290 Make sure that you know how to describe the characteristics of rest based APIs so as an example when 11 00:00:56,290 --> 00:01:02,980 I want to get data from a survey using a REST API that's a get if I want to delete some data it's a 12 00:01:02,980 --> 00:01:11,620 delete MAKE SURE THAT YOU KNOW THE REST API verbs but you don't have to write Python code using REST 13 00:01:11,650 --> 00:01:12,750 API. 14 00:01:13,390 --> 00:01:16,630 You don't have to learn answerable for the exam. 15 00:01:16,630 --> 00:01:19,510 Now in this section I'm going to show you python scripts. 16 00:01:19,510 --> 00:01:21,470 I'm going to show you animal scripts. 17 00:01:21,580 --> 00:01:25,740 You don't however have to learn that for the CCMA exam. 18 00:01:25,870 --> 00:01:31,240 You need to learn that for the definite exam and the developer certifications. 19 00:01:31,240 --> 00:01:33,780 Now is it recommended that you learn Python. 20 00:01:33,790 --> 00:01:34,750 Definitely. 21 00:01:34,750 --> 00:01:39,790 If you're interested in getting ahead in your career learn Python learn animal. 22 00:01:39,820 --> 00:01:42,340 I've been seeing these things for many many years. 23 00:01:42,340 --> 00:01:48,140 Years ago I was explaining the separation of the control plane and data plane. 24 00:01:48,250 --> 00:01:52,590 You can see this video on YouTube as an example made many years ago. 25 00:01:52,600 --> 00:01:55,530 This stuff has now become mainstream. 26 00:01:55,540 --> 00:02:02,500 It's important that you learn Python and sensible for the real world and to get ahead in your career. 27 00:02:02,500 --> 00:02:06,800 But for the CCMA exam you don't have to learn python scripts. 28 00:02:06,850 --> 00:02:08,700 You don't have to learn animal scripts. 29 00:02:08,890 --> 00:02:15,310 Now if I hear that this has changed that now they testing your coding ability. 30 00:02:15,310 --> 00:02:16,690 I'll update this video. 31 00:02:16,990 --> 00:02:22,240 But at the moment because I haven't heard any new updates you can assume that you don't have to learn 32 00:02:22,240 --> 00:02:25,770 python and sensible code for the exam. 33 00:02:25,900 --> 00:02:28,410 You need to understand the principles. 34 00:02:28,420 --> 00:02:35,560 So as an example here they talk about explaining how automation impacts network management. 35 00:02:35,560 --> 00:02:42,580 Let me tell you the world is changing with network automation in the same way that we had autonomous 36 00:02:42,580 --> 00:02:47,290 access points in the past and they are now managed using a controller. 37 00:02:47,290 --> 00:02:52,020 The idea here is we're going to have a controller that manages lots of devices. 38 00:02:52,120 --> 00:02:58,450 Now in the first sort of SDM or software defined networking implementation the protocol used was open 39 00:02:58,450 --> 00:02:58,870 flow. 40 00:02:59,200 --> 00:03:03,670 There's a big difference between the way open flow did things and the way network automation is done 41 00:03:03,670 --> 00:03:06,460 today in the purest form of open flow. 42 00:03:06,450 --> 00:03:10,450 The switches or devices in your network become dumb. 43 00:03:10,450 --> 00:03:16,900 The controller which would simply be a linux ubuntu server as an example controls the devices in the 44 00:03:16,900 --> 00:03:17,640 network. 45 00:03:17,830 --> 00:03:20,530 They lose their brain. 46 00:03:20,590 --> 00:03:26,680 So in the CCMA they talk about separation of control plane and data plane and northbound and southbound 47 00:03:26,710 --> 00:03:30,640 APIs as a start understand the following. 48 00:03:30,640 --> 00:03:32,240 Where is the brain. 49 00:03:32,260 --> 00:03:38,050 Where is the intelligence for the network in the purest open flow implementation. 50 00:03:38,050 --> 00:03:43,080 The brain was removed from the networking device and put into the controller. 51 00:03:43,240 --> 00:03:51,430 If we had 100 routers or 100 switches in a traditional network we have 100 brains every router every 52 00:03:51,430 --> 00:03:53,180 switch controls itself. 53 00:03:53,320 --> 00:03:58,810 It has its own data plane or forwarding plane that's how it switches traffic from wanting to face to 54 00:03:58,810 --> 00:03:59,500 another. 55 00:03:59,500 --> 00:04:01,660 It has its own control plane. 56 00:04:01,660 --> 00:04:03,760 In other words its own brain. 57 00:04:04,060 --> 00:04:09,040 When a rider using a SPF receives an update it updates its routing table. 58 00:04:09,040 --> 00:04:15,030 So the rub routing information base that's a software based table that's populated with rats learnt 59 00:04:15,070 --> 00:04:20,650 through SPF so the brain is populating the routing table with ruts. 60 00:04:20,860 --> 00:04:26,710 So the rub or writing information base is a software based writing table that's then pushed down into 61 00:04:26,710 --> 00:04:29,760 hardware or into the forwarding plane or data plane. 62 00:04:29,770 --> 00:04:33,850 In other words into the Ferb or forwarding information base. 63 00:04:34,000 --> 00:04:35,630 In other words into hardware. 64 00:04:35,680 --> 00:04:41,710 So we have the control plane which is the brain of the device or SPF is populating the writing information 65 00:04:41,710 --> 00:04:42,250 base. 66 00:04:42,250 --> 00:04:44,580 The brain determines where traffic is routed. 67 00:04:44,680 --> 00:04:49,280 Same kind of idea with spanning tree spanning tree BP the user received. 68 00:04:49,450 --> 00:04:54,080 The brain decides once again which ports affording which ports are going to be blocked. 69 00:04:54,130 --> 00:04:57,700 So the thing to remember is the device has a local intelligence. 70 00:04:57,700 --> 00:04:59,740 The brain is on the device. 71 00:04:59,740 --> 00:05:07,740 If we had 100 routers they would each have their own brain brain is localized to the device. 72 00:05:07,980 --> 00:05:15,390 But in the purest open flow example the devices became dumb and we put the brain into the controller 73 00:05:15,710 --> 00:05:20,730 so that the controller centralized controller was the brain for 100 devices. 74 00:05:20,760 --> 00:05:27,630 That's nice in a way because the controller is a central device that you can manipulate and then update 75 00:05:27,870 --> 00:05:30,160 the forwarding of 100 devices. 76 00:05:30,180 --> 00:05:35,520 It also gives the centralized device more visibility of the network so you can see the entire network 77 00:05:35,850 --> 00:05:41,460 instead of the writer just seeing its own local writing table and not having visibility of the entire 78 00:05:41,460 --> 00:05:42,150 network. 79 00:05:42,150 --> 00:05:48,960 There were advantages with with this kind of model Oh SPF uses the SPF algorithm shortest path first 80 00:05:48,990 --> 00:05:49,460 algorithm. 81 00:05:49,470 --> 00:05:50,460 Very complex. 82 00:05:50,460 --> 00:05:56,730 We have a distributed system that then somehow converges to decide which is the best path in the network. 83 00:05:56,730 --> 00:06:03,600 Much easier to put the intelligence in a centralized controller but it didn't work because as an attacker 84 00:06:03,780 --> 00:06:05,400 which device am I going to attack. 85 00:06:05,430 --> 00:06:09,990 I'm going to attack that centralized device if I can take out the controller. 86 00:06:10,100 --> 00:06:15,450 I not only just take out one router I take out 100 writers I basically can destroy your network by just 87 00:06:15,450 --> 00:06:17,160 killing the controller. 88 00:06:17,190 --> 00:06:20,640 There were other problems because Okay so ever centralized device. 89 00:06:20,640 --> 00:06:24,630 But what about redundancy if this thing dies your whole network dies. 90 00:06:24,660 --> 00:06:26,010 So that kind of sucks. 91 00:06:26,040 --> 00:06:31,440 So what you're gonna do is have more than one controller and now you back to the distributed database 92 00:06:31,440 --> 00:06:33,510 scenario or synchronization issue. 93 00:06:33,510 --> 00:06:40,440 How do I synchronize multiple databases in multiple physical controllers to have a single logical controller. 94 00:06:40,500 --> 00:06:45,930 So there were a lot of other issues with this model became a nightmare. 95 00:06:46,010 --> 00:06:50,390 What happens if the rowdies lose connectivity to the centralized controller. 96 00:06:50,390 --> 00:06:50,950 Think about it. 97 00:06:50,960 --> 00:06:56,010 The Rada has its own localized brain in a traditional networking environment. 98 00:06:56,060 --> 00:07:00,710 If it loses connectivity to another writer that's not a problem because he has his own local brain. 99 00:07:00,800 --> 00:07:02,450 That road has its own local brain. 100 00:07:02,780 --> 00:07:07,640 But if you put the brain in the controller and then the road is loose connectivity to the controller 101 00:07:07,670 --> 00:07:11,080 because a link goes down suddenly what are the riders do. 102 00:07:11,090 --> 00:07:14,810 They have no brain so the network dies or breaks. 103 00:07:14,930 --> 00:07:18,630 So a lot of problems with the pure open flow environment. 104 00:07:18,710 --> 00:07:24,350 They then came up with this hybrid approach where we had some intelligence on the devices some intelligence 105 00:07:24,440 --> 00:07:30,800 on the controller where the controller could override what a rudder was doing so we could write open 106 00:07:30,800 --> 00:07:34,590 flow rules to the rider to override traditional networking. 107 00:07:34,670 --> 00:07:39,620 So the ride as an example switch as an example would do traditional riding or traditional switching 108 00:07:39,830 --> 00:07:45,980 but then we could create extra rules here where I could manipulate the flow of traffic from a centralized 109 00:07:45,980 --> 00:07:46,930 controller. 110 00:07:46,940 --> 00:07:52,340 Now one of the cool things with the open flow model and the whole idea of a controller is these devices 111 00:07:52,670 --> 00:07:59,300 talk to the controller using what's called a southbound API so the controller is sitting over here talks 112 00:07:59,300 --> 00:08:02,120 down to the devices using southbound API. 113 00:08:02,120 --> 00:08:07,880 Notice how I've got my hand up here northbound API is southbound API. 114 00:08:07,880 --> 00:08:10,370 Just think south down North up. 115 00:08:10,520 --> 00:08:17,030 So an application developer could write an application talk to the controller using a northbound API. 116 00:08:17,030 --> 00:08:19,200 Typically these would be Rest Api wise. 117 00:08:19,220 --> 00:08:26,000 That's very common today and then a protocol would be used on the southbound API so the controller would 118 00:08:26,000 --> 00:08:31,280 talk down to the riders and switches using some kind of protocol which could be open flow. 119 00:08:31,280 --> 00:08:33,170 That was the original idea. 120 00:08:33,260 --> 00:08:34,740 Could be s an MP. 121 00:08:34,790 --> 00:08:41,030 Don't forget a simple network management protocol been used for years from management stations to networking 122 00:08:41,030 --> 00:08:44,600 devices so S&P could be using the southbound API. 123 00:08:44,600 --> 00:08:52,940 We could use net conf we could use rest conf we could use multiple other options for NPR less BGP. 124 00:08:53,000 --> 00:08:59,160 Basically there were many protocols for CCN HS just have an understanding that we could use rest conf 125 00:08:59,690 --> 00:09:05,410 we could use rest api is actually we could use CLIA we could use as an MP. 126 00:09:05,510 --> 00:09:10,140 Now you don't have to use the rest api of the controller to manipulate devices. 127 00:09:10,550 --> 00:09:16,670 Typically the idea was you you were an application developer used a python script that wrote rules to 128 00:09:16,700 --> 00:09:20,350 the controller which then sent it down to the devices. 129 00:09:20,360 --> 00:09:23,880 The advantage of that was this concept of abstraction. 130 00:09:24,380 --> 00:09:26,870 Complex to write rules to devices. 131 00:09:26,870 --> 00:09:28,140 That was what they said. 132 00:09:28,250 --> 00:09:34,880 Much easier to write stuff to a rest api on the controller so you would write rules to the controller 133 00:09:34,910 --> 00:09:41,130 using the rest api so application uses a high level programming language like Python. 134 00:09:41,240 --> 00:09:47,720 Easy Rest Api in the controller which then uses multiple protocols down to the devices open flow. 135 00:09:47,840 --> 00:09:56,210 Net conf BGP unless less whole bunch of weird and wonderful protocols down to the devices you as the 136 00:09:56,210 --> 00:10:00,050 application develop are being abstracted from the networking devices. 137 00:10:00,050 --> 00:10:06,920 That's the idea but you could do away with a controller and just configure the network devices directly 138 00:10:06,920 --> 00:10:09,270 using a Python script or animal script. 139 00:10:09,290 --> 00:10:15,350 That's what I'm going to show you in the course because that's a lot easier actually to get started 140 00:10:15,350 --> 00:10:15,990 with. 141 00:10:16,030 --> 00:10:21,260 It's a lot easier to say okay let's write a simple python script that updates something on the broader 142 00:10:21,260 --> 00:10:24,440 or pulls information out of the router or switch. 143 00:10:24,470 --> 00:10:31,870 You can mimic this with physical equipment in a lab or in genus 3 or viral or even if you if you like. 144 00:10:32,200 --> 00:10:35,840 So I'm gonna show you some examples of that but just remember you don't have to learn python for the 145 00:10:35,840 --> 00:10:36,580 exam. 146 00:10:36,740 --> 00:10:42,320 You don't have to learn python or sensible programming for the exam but for the real world I'd suggest 147 00:10:42,320 --> 00:10:45,110 that you do learn both of those. 148 00:10:45,110 --> 00:10:48,300 So here they talk about separation of control plane a data plane. 149 00:10:48,350 --> 00:10:52,060 Just note where is the brain local device. 150 00:10:52,130 --> 00:10:57,680 In the old days control plane forwarding plane or data plane was in the device. 151 00:10:57,710 --> 00:11:00,720 So think of the data plane as the forwarding through the ASX. 152 00:11:00,740 --> 00:11:01,840 I've got a router. 153 00:11:01,910 --> 00:11:09,110 Traffic arrives on one interface it gets switched to another interface so data gets sent through the 154 00:11:09,110 --> 00:11:10,010 device. 155 00:11:10,010 --> 00:11:14,750 It's switched on the data plane or forwarding plane that still resides in the device. 156 00:11:14,750 --> 00:11:21,140 Typically it's done using A6 but the control plane or the brain where does it reside. 157 00:11:21,140 --> 00:11:28,460 Today we still want to have the brain in the device open flow the brain was removed and put into a separate 158 00:11:28,460 --> 00:11:29,650 controller. 159 00:11:29,690 --> 00:11:30,810 We don't want to do that. 160 00:11:30,870 --> 00:11:33,230 Cisco devices didn't really support open flow. 161 00:11:33,230 --> 00:11:34,580 They still don't. 162 00:11:34,580 --> 00:11:40,340 The idea is the brain remains on the device but we can use a centralized controller to configure the 163 00:11:40,340 --> 00:11:41,150 devices. 164 00:11:41,390 --> 00:11:46,090 So rather than making the device done we still allow them to do their forwarding still allow them to 165 00:11:46,090 --> 00:11:52,390 have their local brain but we can configure the devices either directly or through a controller which 166 00:11:52,390 --> 00:11:55,140 makes it easier to manage many devices. 167 00:11:55,690 --> 00:11:59,890 So that's one of the central ideas of a controller based network. 168 00:11:59,900 --> 00:12:05,860 Now what I haven't mentioned she has the management play actually three planes control plane or forwarding 169 00:12:05,860 --> 00:12:06,340 plane. 170 00:12:06,340 --> 00:12:08,370 It's like saying write a router. 171 00:12:08,370 --> 00:12:10,530 How is the traffic forwarded through the device. 172 00:12:10,720 --> 00:12:16,090 That always remains on the device because we want high speed switching or forwarding on the device brain 173 00:12:16,090 --> 00:12:18,550 where does it reside typically resides on the device. 174 00:12:18,550 --> 00:12:20,300 But we could have put it into a controller. 175 00:12:20,710 --> 00:12:22,300 Where's the management. 176 00:12:22,300 --> 00:12:24,130 So what's the management plan. 177 00:12:24,160 --> 00:12:31,270 We typically manage a Cisco device using a console or remotely would be telnet bad idea and SSA. 178 00:12:31,330 --> 00:12:38,110 So how do we manage the device now us as humans would use one of those interfaces to configure the device 179 00:12:38,140 --> 00:12:45,400 but to manage the device using a application we in the old days would use SMP simple network management 180 00:12:45,400 --> 00:12:48,070 protocol is an MP has issues. 181 00:12:48,190 --> 00:12:51,990 No one is an MP Virgin wanted to are insecure very easy to hack. 182 00:12:52,000 --> 00:12:55,640 Bad idea to use S&P version 1 and version 2. 183 00:12:55,720 --> 00:13:02,830 It's an MP version 3 supports encryption and authentication much better but it's an MP is not easy. 184 00:13:02,860 --> 00:13:10,030 The OED and the way to extract information from a device is difficult so the rage today which has actually 185 00:13:10,030 --> 00:13:15,680 been going on for a few years is to use a API application programming interface again. 186 00:13:15,720 --> 00:13:21,490 Rest is one of the most popular API is used all over the place. 187 00:13:21,610 --> 00:13:28,060 So when we transition from being a pure network engineer to doing more programming. 188 00:13:28,060 --> 00:13:31,350 The guys from the programming world are used to rest api. 189 00:13:31,360 --> 00:13:35,020 They used all over the place once again in applications. 190 00:13:35,020 --> 00:13:41,800 So when they want to configure network devices it makes sense that that device has a rest api but just 191 00:13:41,800 --> 00:13:45,310 be aware that a lot of old devices will not have a rest api. 192 00:13:45,310 --> 00:13:49,540 You need to use a modern Cisco network device to get a rest api. 193 00:13:49,540 --> 00:13:55,480 So just because rest is cool doesn't mean that all devices are going to support rest. 194 00:13:55,480 --> 00:14:01,990 So in the examples that I'm going to show you in this course which is very much based from my original 195 00:14:01,990 --> 00:14:07,060 Python course I'm going to show you how to configure the devices using telnet and SSA. 196 00:14:07,120 --> 00:14:10,360 Because that's an easy way to get started. 197 00:14:10,360 --> 00:14:17,520 Start with the basics at CCN a level then go and do your definite associate exam. 198 00:14:17,520 --> 00:14:22,530 I highly recommend that you do the definite certification so get your definite certification so that 199 00:14:22,530 --> 00:14:29,580 you can prove to employers that you are not just a network engineer but you also understand programming. 200 00:14:29,760 --> 00:14:33,500 Now as I've said I've been talking about programming for a long time. 201 00:14:33,510 --> 00:14:36,760 I spoke about open flow more than five years ago. 202 00:14:36,930 --> 00:14:43,570 So the idea is this stuff has been bubbling up in the industry but now Cisco have formalized it. 203 00:14:43,650 --> 00:14:51,120 So my recommendation is learn Python and sensible learn the stuff for the real world not for the CCMA 204 00:14:51,450 --> 00:14:56,250 loner for the real world and for the definite certification and go and get your definite certification 205 00:14:56,250 --> 00:15:01,050 as soon as you can so that you can prove to employers that you're not just a network engineer but you 206 00:15:01,080 --> 00:15:02,640 also understand programming. 207 00:15:02,700 --> 00:15:08,640 I'm afraid that being a traditional network engineer with no understanding of programming is over you 208 00:15:08,640 --> 00:15:14,580 will need to learn programming if you wanted to have a good job in future I'm really glad that Cisco 209 00:15:14,580 --> 00:15:20,730 have done this but they've only put 10 percent of the exam being automation and programming so automation 210 00:15:20,730 --> 00:15:27,600 program ability 10 percent of the exam not very big and they use words like explain and compare. 211 00:15:27,600 --> 00:15:32,610 They don't use words like configure or troubleshoot so this is a very high level. 212 00:15:32,610 --> 00:15:38,550 This is typical Cisco way of doing it very high level but then perhaps in the next release of the CCMA 213 00:15:38,880 --> 00:15:42,360 it will become more detailed and you'll be asked more information.