1 00:00:06,580 --> 00:00:09,810 - Now in 11.4, we're going to do our first lesson 2 00:00:09,810 --> 00:00:11,430 on secure communications. 3 00:00:11,430 --> 00:00:14,190 We're gonna revisit secure communications again 4 00:00:14,190 --> 00:00:15,990 in a later lesson. 5 00:00:15,990 --> 00:00:18,420 A secure protocol is going to be a set 6 00:00:18,420 --> 00:00:20,910 of rules and procedures designed to ensure 7 00:00:20,910 --> 00:00:22,980 that we have secure communication between two 8 00:00:22,980 --> 00:00:26,490 or more parties over a network or the internet. 9 00:00:26,490 --> 00:00:28,800 Now the objective of secure communication 10 00:00:28,800 --> 00:00:31,842 or secure protocol is either confidentiality, 11 00:00:31,842 --> 00:00:36,360 integrity, authentication, non-repudiation 12 00:00:36,360 --> 00:00:38,673 or really any combination of those. 13 00:00:40,170 --> 00:00:41,910 We're going to be talking specifically 14 00:00:41,910 --> 00:00:46,910 about two protocols in this lesson, TLS and IPSec. 15 00:00:47,310 --> 00:00:49,800 TLS or Transport Layer Security 16 00:00:49,800 --> 00:00:53,190 and IPSec is Internet protocol security. 17 00:00:53,190 --> 00:00:56,474 And they both are widely used to secure online transactions, 18 00:00:56,474 --> 00:01:00,933 email communication, and other sensitive data transmissions. 19 00:01:01,952 --> 00:01:03,930 But before we talk about TLS 20 00:01:03,930 --> 00:01:05,400 we have to talk about SSL. 21 00:01:05,400 --> 00:01:07,620 And I know we've talked a little bit about SSL already 22 00:01:07,620 --> 00:01:10,050 but I wanna talk some more about SSL. 23 00:01:10,050 --> 00:01:13,890 So SSL, Secure Socket Layer, what's the history? 24 00:01:13,890 --> 00:01:17,280 Well, it was developed back in 1995 by Netscape. 25 00:01:17,280 --> 00:01:20,100 SSL, Secure Socket Layer, is used to establish 26 00:01:20,100 --> 00:01:22,110 a secure communication channel 27 00:01:22,110 --> 00:01:24,570 by negotiation using a stream cipher 28 00:01:24,570 --> 00:01:28,380 and SSL communicates on port 443. 29 00:01:28,380 --> 00:01:30,420 So basically the source would say 30 00:01:30,420 --> 00:01:33,210 to the destination, hey, destination, I wanna talk to you. 31 00:01:33,210 --> 00:01:34,950 The destination says would say, cool 32 00:01:34,950 --> 00:01:37,140 but we need a secure channel. 33 00:01:37,140 --> 00:01:38,940 And the the source would say, okay, 34 00:01:38,940 --> 00:01:42,030 well let me tell you what I am capable of. 35 00:01:42,030 --> 00:01:45,360 And then based on negotiating that, right, 36 00:01:45,360 --> 00:01:46,590 the destination will say, okay, 37 00:01:46,590 --> 00:01:49,140 this is how we're going to have a secure channel 38 00:01:49,140 --> 00:01:51,243 communicating on 443. 39 00:01:52,560 --> 00:01:54,390 So what's the current state? 40 00:01:54,390 --> 00:01:59,390 Well secure sock layer SSL is insecure and outdated. 41 00:01:59,580 --> 00:02:04,230 In 2015, SSL 3.0 was deprecated, meaning found to be weak 42 00:02:04,230 --> 00:02:07,410 by the internet engineering task force, the IETF, 43 00:02:07,410 --> 00:02:09,450 due to numerous security vulnerabilities 44 00:02:09,450 --> 00:02:11,610 that have been discovered over the years 45 00:02:11,610 --> 00:02:14,910 and new vulnerabilities continue to be discovered. 46 00:02:14,910 --> 00:02:18,060 So we don't wanna be using SSL anymore. 47 00:02:18,060 --> 00:02:21,570 Matter of fact, most browsers no longer support SSL 48 00:02:21,570 --> 00:02:24,540 and we wanna make sure that SSL previous versions 49 00:02:24,540 --> 00:02:27,810 like 2.0 and 3.0 are disabled, right? 50 00:02:27,810 --> 00:02:30,780 Because when they're enabled, it makes the system vulnerable 51 00:02:30,780 --> 00:02:32,610 to an attack we've already discussed 52 00:02:32,610 --> 00:02:34,413 which is a downgrade attack. 53 00:02:35,520 --> 00:02:39,360 So what are we gonna use instead if we're not using SSL? 54 00:02:39,360 --> 00:02:41,820 Well, that's where TLS comes in. 55 00:02:41,820 --> 00:02:45,750 Introduced in 1999, transport layer security is used to 56 00:02:45,750 --> 00:02:48,090 establish a secure communication channel 57 00:02:48,090 --> 00:02:50,700 by using a cryptographic key exchange. 58 00:02:50,700 --> 00:02:51,660 And you're familiar with those. 59 00:02:51,660 --> 00:02:54,300 We've seen how cryptographic key exchanges work. 60 00:02:54,300 --> 00:02:56,463 TLS communicates on port 443. 61 00:02:58,740 --> 00:03:02,318 Now one of the confusions I think about TLS 62 00:03:02,318 --> 00:03:05,490 is that a lot of us still, hopefully I don't, 63 00:03:05,490 --> 00:03:09,000 but a lot of us do still use the term SSL 64 00:03:09,000 --> 00:03:12,990 when we mean TLS because we've been using SSL for so long 65 00:03:12,990 --> 00:03:16,890 that even though we've already transitioned to TLS, 66 00:03:16,890 --> 00:03:19,260 people will still use the term SSL 67 00:03:19,260 --> 00:03:20,520 and it gets even a little more confusing 68 00:03:20,520 --> 00:03:21,720 'cause it runs on the same port. 69 00:03:21,720 --> 00:03:23,820 It runs on port 443. 70 00:03:23,820 --> 00:03:26,370 So if you're talking to someone and they're talking 71 00:03:26,370 --> 00:03:28,435 about SSL, don't hesitate to stop them and say 72 00:03:28,435 --> 00:03:31,264 do you mean SSL or TLS? 73 00:03:31,264 --> 00:03:32,370 You know, you won't sound wonky. 74 00:03:32,370 --> 00:03:34,830 You'll sound like you really just trying to understand. 75 00:03:34,830 --> 00:03:37,350 So TLS is a successor and the recommended 76 00:03:37,350 --> 00:03:39,240 replacement for SSL. 77 00:03:39,240 --> 00:03:41,640 TLS is used to provide confidentiality, 78 00:03:41,640 --> 00:03:44,400 integrity and authenticity. 79 00:03:44,400 --> 00:03:47,460 Now, TLS uses a block encryption cipher 80 00:03:47,460 --> 00:03:49,860 and does include some advanced security features 81 00:03:49,860 --> 00:03:51,720 and improved algorithms. 82 00:03:51,720 --> 00:03:54,210 Now the current version of TLS is 1.3 83 00:03:54,210 --> 00:03:55,890 and you always wanna be using the current version. 84 00:03:55,890 --> 00:03:57,420 So as a new version comes out, 85 00:03:57,420 --> 00:03:59,040 you'll wanna move to a new version 86 00:03:59,040 --> 00:04:01,590 and the IETF has officially declared 87 00:04:01,590 --> 00:04:06,450 that both TLS 1.0 and TLS 1.1 are deprecated, 88 00:04:06,450 --> 00:04:10,560 again meaning weak and vulnerable and should not be used. 89 00:04:10,560 --> 00:04:13,260 So let's take a look at how a TLS session actually works, 90 00:04:13,260 --> 00:04:14,523 how a connection is made. 91 00:04:15,579 --> 00:04:18,480 First, a client does a hello command 92 00:04:18,480 --> 00:04:21,300 and that's really the secure connection requesting 93 00:04:21,300 --> 00:04:25,710 a TLS version, supported ciphers and a random number. 94 00:04:25,710 --> 00:04:27,480 The server does a "hello", 95 00:04:27,480 --> 00:04:30,180 which is really a secure connection response 96 00:04:30,180 --> 00:04:33,060 including TLS version, selected cipher suite 97 00:04:33,060 --> 00:04:34,353 and a random number. 98 00:04:35,640 --> 00:04:37,740 Then we have a certificate exchange here. 99 00:04:37,740 --> 00:04:40,230 The server's going to send its digital certificate 100 00:04:40,230 --> 00:04:42,960 which contains the server's public key 101 00:04:42,960 --> 00:04:45,873 and other trusted information to the client. 102 00:04:47,119 --> 00:04:49,080 Then we have a server key exchange 103 00:04:49,080 --> 00:04:50,970 where the server's going to send its public key. 104 00:04:50,970 --> 00:04:53,160 Remember, public keys are freely distributed, 105 00:04:53,160 --> 00:04:55,530 to the client along with information needed 106 00:04:55,530 --> 00:04:59,400 to establish a shared secret or a symmetric key. 107 00:04:59,400 --> 00:05:01,290 Remember, symmetric key is where you use the same key 108 00:05:01,290 --> 00:05:02,850 to encrypt and decrypt. 109 00:05:02,850 --> 00:05:04,200 Why are we using a symmetric key? 110 00:05:04,200 --> 00:05:06,150 Because it is computationally efficient 111 00:05:06,150 --> 00:05:08,133 and works well in large blocks of data. 112 00:05:09,480 --> 00:05:11,070 Then we'll have a client key exchange 113 00:05:11,070 --> 00:05:13,170 where the client generates a symmetric key, 114 00:05:13,170 --> 00:05:15,180 encrypts it with the server's public key 115 00:05:15,180 --> 00:05:17,760 and sends it back to the server. 116 00:05:17,760 --> 00:05:19,770 Then we'll have our cipher specification where 117 00:05:19,770 --> 00:05:21,570 both the client and the server switch 118 00:05:21,570 --> 00:05:25,020 to the agreed upon cipher suite using that symmetric key. 119 00:05:25,020 --> 00:05:27,090 And then we have confirmation, the client 120 00:05:27,090 --> 00:05:29,670 and the server exchange messages to verify 121 00:05:29,670 --> 00:05:32,343 that a secure connection has been established. 122 00:05:34,200 --> 00:05:36,600 Next step, we wanna talk about IP security 123 00:05:36,600 --> 00:05:40,590 or internet protocol security, often referred to as IPSec 124 00:05:40,590 --> 00:05:43,980 which is a protocol suite used to secure IP 125 00:05:43,980 --> 00:05:45,780 or internet protocol communications 126 00:05:45,780 --> 00:05:48,600 by providing authentication, integrity 127 00:05:48,600 --> 00:05:51,360 and confidentiality services. 128 00:05:51,360 --> 00:05:54,930 Now introduced in the mid 1990s, IPSec was originally 129 00:05:54,930 --> 00:05:57,420 designed to secure host to host communication. 130 00:05:57,420 --> 00:06:01,260 Now, IPSec operates at the network layer of the OSI model. 131 00:06:01,260 --> 00:06:03,480 That's layer three and can be used 132 00:06:03,480 --> 00:06:06,180 to encrypt data being sent to any system 133 00:06:06,180 --> 00:06:09,240 that can be identified by an IP address. 134 00:06:09,240 --> 00:06:12,420 Now IPSec can be implemented in two modes, tunnel mode 135 00:06:12,420 --> 00:06:15,033 which is a default mode and transport mode. 136 00:06:15,870 --> 00:06:18,540 Now, even though IPSec was originally designed just 137 00:06:18,540 --> 00:06:21,390 to secure kind of host to host communication, right, 138 00:06:21,390 --> 00:06:24,090 inside a a server room, at that point 139 00:06:24,090 --> 00:06:29,090 IPSec has now become the defacto standard for IP-based VPNs. 140 00:06:31,260 --> 00:06:34,650 So looking at our two IPSec modes, we have tunnel mode. 141 00:06:34,650 --> 00:06:37,950 In tunnel mode the entire IP packet is encapsulated 142 00:06:37,950 --> 00:06:41,010 to become the payload of a new IP packet. 143 00:06:41,010 --> 00:06:44,070 And a new IP header is added on top 144 00:06:44,070 --> 00:06:46,020 of the original IP packet. 145 00:06:46,020 --> 00:06:48,240 So in tunnel mode, entire thing, right? 146 00:06:48,240 --> 00:06:50,940 The entire packet is gonna be encapsulated 147 00:06:50,940 --> 00:06:53,370 and it becomes the payload of another packet. 148 00:06:53,370 --> 00:06:56,760 And that other packet will have a new header. 149 00:06:56,760 --> 00:07:00,300 In transport mode, the payload is encrypted, 150 00:07:00,300 --> 00:07:02,910 but not the IP header information. 151 00:07:02,910 --> 00:07:06,150 So we don't have to have a packet on top of a packet. 152 00:07:06,150 --> 00:07:08,964 Transport mode has less overhead 153 00:07:08,964 --> 00:07:12,720 but could be considered less secure. 154 00:07:12,720 --> 00:07:15,390 So tunnel mode's gonna be used for configurations 155 00:07:15,390 --> 00:07:17,100 that need a really secure connection 156 00:07:17,100 --> 00:07:18,963 between two different networks. 157 00:07:20,640 --> 00:07:23,340 So I just mentioned that IPSec was a defacto standard 158 00:07:23,340 --> 00:07:26,370 for VPNs so let's talk about VPNs. 159 00:07:26,370 --> 00:07:29,160 VPNs is a virtual private network designed 160 00:07:29,160 --> 00:07:32,370 to facilitate secure remote access communication 161 00:07:32,370 --> 00:07:33,780 over a public network. 162 00:07:33,780 --> 00:07:36,030 And what's the public network we're talking about? 163 00:07:36,030 --> 00:07:38,280 Of course, over the internet. 164 00:07:38,280 --> 00:07:41,400 VPNs are an incredible cost-effective alternative 165 00:07:41,400 --> 00:07:44,689 to dedicated point-to-point connections like a T1 166 00:07:44,689 --> 00:07:48,150 or a T3 or an E1 or E3 which were very expensive 167 00:07:48,150 --> 00:07:50,130 and you'd have to go to the, you know, 168 00:07:50,130 --> 00:07:52,410 a phone company to get and you might have to wait weeks 169 00:07:52,410 --> 00:07:54,720 or even months till it got installed. 170 00:07:54,720 --> 00:07:56,550 Now we can just use the circuitry 171 00:07:56,550 --> 00:07:58,500 of the internet for this communication. 172 00:07:59,550 --> 00:08:03,900 VPNs isolate network frames from the surrounding networking 173 00:08:03,900 --> 00:08:07,230 by using a process known as encapsulation or tunneling. 174 00:08:07,230 --> 00:08:09,660 Full tunneling requires that all traffic is routed 175 00:08:09,660 --> 00:08:12,600 over the VPN and split tunneling says some traffic 176 00:08:12,600 --> 00:08:13,890 can go over the VPN and some 177 00:08:13,890 --> 00:08:15,690 can directly access the internet. 178 00:08:15,690 --> 00:08:17,280 So imagine you're at home, you connect 179 00:08:17,280 --> 00:08:18,990 via your VPN to the office. 180 00:08:18,990 --> 00:08:20,700 Full tunneling means everything you do 181 00:08:20,700 --> 00:08:22,200 goes through that tunnel. 182 00:08:22,200 --> 00:08:23,880 Split tunneling would be okay, 183 00:08:23,880 --> 00:08:27,810 I am connected to the office through my VPN 184 00:08:27,810 --> 00:08:29,190 but I can also go out directly 185 00:08:29,190 --> 00:08:32,070 to the internet without going through that VPN. 186 00:08:32,070 --> 00:08:33,570 That would be split tunneling. 187 00:08:36,030 --> 00:08:39,450 Now, the two most used protocols for virtual private network 188 00:08:39,450 --> 00:08:43,380 or VPN are gonna be are IPSec and TLS. 189 00:08:43,380 --> 00:08:47,400 Now IPSec VPNs are widely used for site to site VPNs 190 00:08:47,400 --> 00:08:49,350 and remote access VPNs. 191 00:08:49,350 --> 00:08:52,900 Now because IPSec operates at OSI layer three, 192 00:08:52,900 --> 00:08:57,690 IPSec VPNs can support all IP-based applications. 193 00:08:57,690 --> 00:09:00,630 TLS VPNs are commonly used 194 00:09:00,630 --> 00:09:03,420 for remote access VPN configurations. 195 00:09:03,420 --> 00:09:07,167 Because TL operates at the OSI layer seven, right, 196 00:09:07,167 --> 00:09:12,167 TLS VPNs generally only support browser-based applications. 197 00:09:13,980 --> 00:09:17,820 I wanna just briefly introduce you to two more concepts 198 00:09:17,820 --> 00:09:20,940 of ways that we can further secure our networks. 199 00:09:20,940 --> 00:09:23,040 And the first is having software-defined 200 00:09:23,040 --> 00:09:25,770 wide area networks or SD-WANs. 201 00:09:25,770 --> 00:09:28,592 A software defined wide area network is a technology 202 00:09:28,592 --> 00:09:31,320 that enables the creation of a software-defined 203 00:09:31,320 --> 00:09:35,340 network overlay over an existing wide area network. 204 00:09:35,340 --> 00:09:36,960 So why would we do that? 205 00:09:36,960 --> 00:09:38,430 Well, the SD-WAN focuses 206 00:09:38,430 --> 00:09:41,400 on providing software defined application routing 207 00:09:41,400 --> 00:09:44,910 to the WAN but it includes built-in security features 208 00:09:44,910 --> 00:09:49,200 such as encryption, firewalling, and threat detection 209 00:09:49,200 --> 00:09:52,083 and response to improve the security of the network. 210 00:09:54,270 --> 00:09:56,730 The other concept I want you to become familiar with 211 00:09:56,730 --> 00:10:01,730 is known as Secure Access Service Edge or SASE, 212 00:10:01,920 --> 00:10:04,170 which is a cloud-based network security model 213 00:10:04,170 --> 00:10:06,360 that really combines wide area networking 214 00:10:06,360 --> 00:10:10,593 and security functions into a single cloud-based service. 215 00:10:12,060 --> 00:10:14,730 Now, SASE is based on the principle of software-defined 216 00:10:14,730 --> 00:10:18,090 networking and the SASE architecture 217 00:10:18,090 --> 00:10:20,100 integrates various security functions 218 00:10:20,100 --> 00:10:23,430 such as a secure web gateway, a firewall-as-a-service, 219 00:10:23,430 --> 00:10:27,600 a secure access gateway, a cloud access security broker 220 00:10:27,600 --> 00:10:29,820 and zero trust network access 221 00:10:29,820 --> 00:10:33,363 into a single unified in the cloud platform. 222 00:10:35,160 --> 00:10:36,990 That was a lot of stuff, wasn't it? 223 00:10:36,990 --> 00:10:39,210 Yeah, let's do a three second challenge together. 224 00:10:39,210 --> 00:10:41,400 Five challenge questions, three seconds each. 225 00:10:41,400 --> 00:10:42,600 You ready? 226 00:10:42,600 --> 00:10:43,800 1, 2, 3. 227 00:10:43,800 --> 00:10:45,570 We're gonna start. 228 00:10:45,570 --> 00:10:48,390 This protocol is a successor to SSL. 229 00:10:48,390 --> 00:10:49,653 1, 2, 3. 230 00:10:51,840 --> 00:10:53,163 That's gonna be TLS. 231 00:10:54,150 --> 00:10:57,060 Number two, OSI layer three protocol suite 232 00:10:57,060 --> 00:10:59,490 that can be used to encrypt data being sent 233 00:10:59,490 --> 00:11:03,633 between any systems identified by an IP address. 234 00:11:05,010 --> 00:11:06,663 1, 2, 3. 235 00:11:07,590 --> 00:11:08,913 That's gonna be IPSec. 236 00:11:10,140 --> 00:11:12,450 Number three, in this IPSec mode 237 00:11:12,450 --> 00:11:15,420 the entire original IP packet is encapsulated 238 00:11:15,420 --> 00:11:18,153 to become the payload of a new IP packet. 239 00:11:19,230 --> 00:11:20,883 1, 2, 3. 240 00:11:21,720 --> 00:11:23,043 It's gonna be tunnel mode. 241 00:11:24,000 --> 00:11:25,380 Number four. 242 00:11:25,380 --> 00:11:28,260 This VPN encapsulation approach allows the routing 243 00:11:28,260 --> 00:11:31,560 of some traffic over the VPN while letting other traffic 244 00:11:31,560 --> 00:11:33,423 directly access the internet. 245 00:11:34,410 --> 00:11:35,973 1, 2, 3. 246 00:11:37,110 --> 00:11:39,120 That's gonna be split tunneling. 247 00:11:39,120 --> 00:11:41,340 And lastly, number five. 248 00:11:41,340 --> 00:11:43,200 This cloud-based network security model 249 00:11:43,200 --> 00:11:45,150 combines wide area networking 250 00:11:45,150 --> 00:11:49,560 and security functions into a single cloud-based service. 251 00:11:49,560 --> 00:11:51,183 1, 2, 3. 252 00:11:52,050 --> 00:11:56,610 That's gonna be secure access service edge, SASE. 253 00:11:56,610 --> 00:11:58,083 Not an easy thing to say. 254 00:11:59,910 --> 00:12:02,250 All right, that takes us to a security-in-action 255 00:12:02,250 --> 00:12:05,760 about secure communications and VPN options. 256 00:12:05,760 --> 00:12:07,890 Your company is growing rapidly. 257 00:12:07,890 --> 00:12:10,290 Two remote offices are planned, and employees 258 00:12:10,290 --> 00:12:13,710 in emerging markets are being asked to work from home. 259 00:12:13,710 --> 00:12:16,800 They'll be connecting to an on-premises data center 260 00:12:16,800 --> 00:12:19,440 and cost is a consideration. 261 00:12:19,440 --> 00:12:21,360 What is your best option for expanding 262 00:12:21,360 --> 00:12:22,860 your network securely? 263 00:12:22,860 --> 00:12:25,650 So we talked about different VPN options. 264 00:12:25,650 --> 00:12:28,170 Based on what we're doing, two remote offices 265 00:12:28,170 --> 00:12:30,540 plus employees working from home, 266 00:12:30,540 --> 00:12:33,150 they're connecting to an on-premise data center 267 00:12:33,150 --> 00:12:35,520 and cost is a consideration. 268 00:12:35,520 --> 00:12:37,080 So go ahead and put me on pause. 269 00:12:37,080 --> 00:12:38,940 Think about what your best options are 270 00:12:38,940 --> 00:12:40,863 for expanding your network security. 271 00:12:43,290 --> 00:12:44,790 Well, here's some of your options. 272 00:12:44,790 --> 00:12:46,710 For the remote office, we're going 273 00:12:46,710 --> 00:12:48,180 to have site to site, right? 274 00:12:48,180 --> 00:12:50,310 We're not doing individuals, you know, host to host, 275 00:12:50,310 --> 00:12:51,690 we're doing site to site. 276 00:12:51,690 --> 00:12:53,340 So promptly our best bet is gonna be 277 00:12:53,340 --> 00:12:56,640 a site to site IPSec VPN, right? 278 00:12:56,640 --> 00:12:58,593 So remote office to corporate. 279 00:12:59,790 --> 00:13:01,530 Now for work at home users, 280 00:13:01,530 --> 00:13:03,870 it's gonna be important to get an understanding of 281 00:13:03,870 --> 00:13:08,870 how often and with what applications they need to connect. 282 00:13:09,030 --> 00:13:12,090 Because our options to consider will be a TLS VPN 283 00:13:12,090 --> 00:13:17,090 which is browser based, or a host to site IPSec VPN. 284 00:13:17,310 --> 00:13:19,020 So hard to know, we don't have really have enough 285 00:13:19,020 --> 00:13:21,480 information to really make a recommendation 286 00:13:21,480 --> 00:13:24,120 for our home users but we can explore both 287 00:13:24,120 --> 00:13:26,010 by saying what do we need to do? 288 00:13:26,010 --> 00:13:27,180 What are they gonna be doing? 289 00:13:27,180 --> 00:13:30,810 How often they can gonna connect, through what applications? 290 00:13:30,810 --> 00:13:33,870 That'll help us kind of further refine 291 00:13:33,870 --> 00:13:35,770 what our recommendations are gonna be. 292 00:13:36,630 --> 00:13:37,890 Been able to do this? 293 00:13:37,890 --> 00:13:38,723 Absolutely. 294 00:13:38,723 --> 00:13:39,723 Security in action. 295 00:13:40,800 --> 00:13:42,360 All right, there's your word cloud. 296 00:13:42,360 --> 00:13:43,193 You know what to do. 297 00:13:43,193 --> 00:13:45,270 Do not move on until you're really comfortable 298 00:13:45,270 --> 00:13:47,970 and confident with all of these terms and concepts. 299 00:13:47,970 --> 00:13:50,160 And when you are, head on over 300 00:13:50,160 --> 00:13:52,260 to our lesson quiz and I'll see you there.