1 00:00:00,330 --> 00:00:01,260 In this video, 2 00:00:01,260 --> 00:00:03,630 we're going to discuss some other issues you may need 3 00:00:03,630 --> 00:00:04,560 to troubleshoot, 4 00:00:04,560 --> 00:00:06,570 things like low optical link budgets, 5 00:00:06,570 --> 00:00:09,270 certificate issues, license feature issues, 6 00:00:09,270 --> 00:00:12,000 BYOD challenges and hardware failures. 7 00:00:12,000 --> 00:00:14,850 First, let's talk about low optical link budgets. 8 00:00:14,850 --> 00:00:17,700 And what exactly is an optical link budget? 9 00:00:17,700 --> 00:00:19,830 Now, an optical link budget is a calculation 10 00:00:19,830 --> 00:00:21,840 that considers all the anticipated losses 11 00:00:21,840 --> 00:00:24,420 along the length of a fiber optic connection. 12 00:00:24,420 --> 00:00:25,800 This is important to understand, 13 00:00:25,800 --> 00:00:26,700 because the light signal 14 00:00:26,700 --> 00:00:28,650 that's going across that fiber optic cable, 15 00:00:28,650 --> 00:00:31,950 will lose signal strength as it travels down this cable. 16 00:00:31,950 --> 00:00:34,680 Now, this occurs naturally due to the distance of the cable, 17 00:00:34,680 --> 00:00:36,870 as well as from losses due to multiplexing, 18 00:00:36,870 --> 00:00:39,300 bends in your cable, imperfect connections, 19 00:00:39,300 --> 00:00:43,020 patches or splices that happen along the fiber optic cable. 20 00:00:43,020 --> 00:00:45,480 If you experience a low optical link budget, 21 00:00:45,480 --> 00:00:47,790 your fiber connection will experience issues, 22 00:00:47,790 --> 00:00:49,740 such as reduced transmission efficiency, 23 00:00:49,740 --> 00:00:50,970 slower connection speeds, 24 00:00:50,970 --> 00:00:53,160 or even downtime on that connection. 25 00:00:53,160 --> 00:00:55,620 To measure the condition of your fiber optic connection, 26 00:00:55,620 --> 00:00:58,170 you're going to use an optical time-domain reflectometer 27 00:00:58,170 --> 00:01:00,210 to measure the amount of losses or reflections 28 00:01:00,210 --> 00:01:02,100 that are occurring in the connection. 29 00:01:02,100 --> 00:01:04,650 This reading from the optical time-domain reflectometer, 30 00:01:04,650 --> 00:01:07,380 is going to be reported in decibels per kilometer. 31 00:01:07,380 --> 00:01:08,213 And this indicates 32 00:01:08,213 --> 00:01:10,860 how much attenuation and degradation is occurring 33 00:01:10,860 --> 00:01:12,750 over the length of that connection. 34 00:01:12,750 --> 00:01:16,740 Normally, you should experience 0.25 decibels per kilometer 35 00:01:16,740 --> 00:01:18,540 for a standard fiber optic cable. 36 00:01:18,540 --> 00:01:20,400 But if you experience a higher rate than this, 37 00:01:20,400 --> 00:01:23,040 then you may have a low optical link budget. 38 00:01:23,040 --> 00:01:24,570 To calculate your link budget, 39 00:01:24,570 --> 00:01:26,550 you simply take the receiver's power budget, 40 00:01:26,550 --> 00:01:29,040 or how much initial signal you're going to be transmitting out 41 00:01:29,040 --> 00:01:30,930 and then you subtract any multiplexing 42 00:01:30,930 --> 00:01:32,640 and demultiplexing losses, 43 00:01:32,640 --> 00:01:34,470 as well as losses from the fiber itself 44 00:01:34,470 --> 00:01:37,080 that's caused by those distances and the imperfections 45 00:01:37,080 --> 00:01:39,600 and any losses from the connectors or patch panels 46 00:01:39,600 --> 00:01:41,190 that are being used as well. 47 00:01:41,190 --> 00:01:44,280 Now, this will give you the total optical link budget. 48 00:01:44,280 --> 00:01:47,160 For example, let's say I designed a fiber optic circuit 49 00:01:47,160 --> 00:01:49,020 with a receiver that can sense light received 50 00:01:49,020 --> 00:01:52,320 between negative-seven decibels and negative-23 decibels. 51 00:01:52,320 --> 00:01:55,230 And I send the signal out at positive-five decibels. 52 00:01:55,230 --> 00:01:57,660 Now, if I only have a loss of 20 decibels 53 00:01:57,660 --> 00:01:58,710 due to the distance, 54 00:01:58,710 --> 00:02:00,810 the connectors and a splice in that cable, 55 00:02:00,810 --> 00:02:02,820 the receiver's going to be able to pick up that signal, 56 00:02:02,820 --> 00:02:04,830 because I still have negative-15 decibels 57 00:02:04,830 --> 00:02:07,680 of light signal being received at that distant end. 58 00:02:07,680 --> 00:02:10,440 And negative-15 is in between negative-seven 59 00:02:10,440 --> 00:02:12,000 and negative-23. 60 00:02:12,000 --> 00:02:14,430 On the other hand, if the fiber connection was broken 61 00:02:14,430 --> 00:02:17,130 and somebody went to repair it by splicing that connection, 62 00:02:17,130 --> 00:02:18,377 maybe they did a really bad job of it 63 00:02:18,377 --> 00:02:21,870 and it adds an extra 25 decibels of signal loss. 64 00:02:21,870 --> 00:02:24,360 Now, I'm going to transmit at the same five decibels 65 00:02:24,360 --> 00:02:25,500 that I was before, 66 00:02:25,500 --> 00:02:27,450 but I'm losing 15 decibels 67 00:02:27,450 --> 00:02:29,610 for distance and that first splice. 68 00:02:29,610 --> 00:02:31,890 And now, because of this poor second splice, 69 00:02:31,890 --> 00:02:34,080 I'm losing another 25 decibels. 70 00:02:34,080 --> 00:02:36,630 This brings my total value on the receiving end 71 00:02:36,630 --> 00:02:38,520 to negative-35 decibels. 72 00:02:38,520 --> 00:02:41,130 And that means the receiver can't pick up that signal, 73 00:02:41,130 --> 00:02:42,840 because it can only sense the signals 74 00:02:42,840 --> 00:02:45,570 between negative-seven and negative-23 decibels. 75 00:02:45,570 --> 00:02:49,050 And negative-35 is far too weak for the receiver to see it. 76 00:02:49,050 --> 00:02:51,720 Now, we're going to have a broken fiber link essentially, 77 00:02:51,720 --> 00:02:54,330 because we have a low optical link budget level. 78 00:02:54,330 --> 00:02:56,520 So what can we do to fix this? 79 00:02:56,520 --> 00:02:59,100 Well, we can either increase the power of the transmitter 80 00:02:59,100 --> 00:03:02,340 to say plus-20 decibels instead of plus-five decibels, 81 00:03:02,340 --> 00:03:04,200 or we can have somebody go back 82 00:03:04,200 --> 00:03:06,690 and try to do a better job of splicing that cable. 83 00:03:06,690 --> 00:03:09,030 Now, this isn't a very realistic example. 84 00:03:09,030 --> 00:03:12,000 Because most professional splices will only cost a loss 85 00:03:12,000 --> 00:03:14,190 of 0.1 or 0.2 decibels. 86 00:03:14,190 --> 00:03:15,480 But hopefully, you're getting the idea 87 00:03:15,480 --> 00:03:17,700 of how a low optical link budget can work 88 00:03:17,700 --> 00:03:20,130 and negatively affect your fiber networks. 89 00:03:20,130 --> 00:03:21,810 Next, we have certificate issues 90 00:03:21,810 --> 00:03:23,970 that can cause network issues for us as well. 91 00:03:23,970 --> 00:03:26,280 A digital certificate is used as a credential 92 00:03:26,280 --> 00:03:28,290 to facilitate the verification of identities 93 00:03:28,290 --> 00:03:30,660 between users inside of a transaction. 94 00:03:30,660 --> 00:03:32,400 For example, when you attempt to connect 95 00:03:32,400 --> 00:03:34,920 to an e-commerce site over HTTPS, 96 00:03:34,920 --> 00:03:37,290 your network client uses digital certificates 97 00:03:37,290 --> 00:03:38,940 to validate the server's identity 98 00:03:38,940 --> 00:03:40,920 and decide if it can really trust that server 99 00:03:40,920 --> 00:03:43,290 when sending sensitive information over to it. 100 00:03:43,290 --> 00:03:45,630 The most common certificate issues are going to occur 101 00:03:45,630 --> 00:03:48,270 on a website's SSL or TLS certificate 102 00:03:48,270 --> 00:03:50,430 when it's displaying as untrusted. 103 00:03:50,430 --> 00:03:52,680 Now, this occurs for one of three reasons. 104 00:03:52,680 --> 00:03:54,870 It can be that the digital certificate is not signed 105 00:03:54,870 --> 00:03:56,550 by a trusted certificate authority, 106 00:03:56,550 --> 00:03:58,560 the certificate itself has already expired, 107 00:03:58,560 --> 00:04:01,050 or the server didn't have a certificate associated 108 00:04:01,050 --> 00:04:03,000 with a trusted root certificate. 109 00:04:03,000 --> 00:04:05,490 Now, regardless of which of these three things is happening, 110 00:04:05,490 --> 00:04:07,440 the end result is going to be the same. 111 00:04:07,440 --> 00:04:10,320 Your client's browser is not going to show a secure connection 112 00:04:10,320 --> 00:04:11,730 over HTTPS, 113 00:04:11,730 --> 00:04:14,550 because its web browser and the server are not communicating 114 00:04:14,550 --> 00:04:16,170 over a secure tunnel. 115 00:04:16,170 --> 00:04:17,910 Now, in either of these cases, 116 00:04:17,910 --> 00:04:20,040 you can't solve the issue for your network clients. 117 00:04:20,040 --> 00:04:21,870 Because you don't own that web server. 118 00:04:21,870 --> 00:04:24,330 But if you were the one who owned that web server, 119 00:04:24,330 --> 00:04:26,520 then it becomes your problem to fix. 120 00:04:26,520 --> 00:04:27,600 Now, in this case, 121 00:04:27,600 --> 00:04:29,340 you need to purchase a digital certificate 122 00:04:29,340 --> 00:04:31,800 from a trusted certificate authority and install it, 123 00:04:31,800 --> 00:04:34,680 or you need to renew your expired digital certificate, 124 00:04:34,680 --> 00:04:36,390 or you need to install a certificate 125 00:04:36,390 --> 00:04:38,040 from a trusted certificate authority 126 00:04:38,040 --> 00:04:40,830 with a valid root certificate on your server. 127 00:04:40,830 --> 00:04:42,360 In addition to using digital certificates 128 00:04:42,360 --> 00:04:44,160 with HTTPS websites, 129 00:04:44,160 --> 00:04:46,950 we also can use digital certificates inside of our networks 130 00:04:46,950 --> 00:04:51,240 for network authentication using 802.1X with EAP. 131 00:04:51,240 --> 00:04:52,290 In these cases, 132 00:04:52,290 --> 00:04:53,220 your security team's, 133 00:04:53,220 --> 00:04:55,740 going to run your organization's own certificate authority 134 00:04:55,740 --> 00:04:57,330 to create these digital certificates 135 00:04:57,330 --> 00:05:00,030 and issue them to the network clients and the servers. 136 00:05:00,030 --> 00:05:01,590 Again, if you're having issues 137 00:05:01,590 --> 00:05:02,910 with these digital certificates, 138 00:05:02,910 --> 00:05:04,440 you need to ensure they're trusted, 139 00:05:04,440 --> 00:05:05,550 that they're not expired 140 00:05:05,550 --> 00:05:06,960 and that they're installed properly 141 00:05:06,960 --> 00:05:09,540 on the network devices and the network clients. 142 00:05:09,540 --> 00:05:12,120 Next, we need to talk about license feature issues 143 00:05:12,120 --> 00:05:13,770 that could arise in your networks. 144 00:05:13,770 --> 00:05:16,140 Sometimes, when troubleshooting issues in your network, 145 00:05:16,140 --> 00:05:17,790 you may come across an error message, 146 00:05:17,790 --> 00:05:20,340 such as "Error, feature not licensed." 147 00:05:20,340 --> 00:05:21,750 Now, as you can see in this example 148 00:05:21,750 --> 00:05:23,790 from a NetScaler VPX appliance, 149 00:05:23,790 --> 00:05:25,200 there are many different features 150 00:05:25,200 --> 00:05:26,760 that are enabled or disabled, 151 00:05:26,760 --> 00:05:27,810 based upon the license 152 00:05:27,810 --> 00:05:29,940 that's been purchased by this organization. 153 00:05:29,940 --> 00:05:32,460 For example, the license they have purchased will allow them 154 00:05:32,460 --> 00:05:34,620 to do load balancing and content switching. 155 00:05:34,620 --> 00:05:37,440 But it does not support global server load balancing, 156 00:05:37,440 --> 00:05:38,520 or clustering. 157 00:05:38,520 --> 00:05:40,050 This is a different feature set 158 00:05:40,050 --> 00:05:42,780 that requires a different and more expensive license. 159 00:05:42,780 --> 00:05:43,860 Now, if you get an error, 160 00:05:43,860 --> 00:05:45,510 concerning a particular license feature 161 00:05:45,510 --> 00:05:47,460 in this or another network device, 162 00:05:47,460 --> 00:05:48,810 you first need to determine 163 00:05:48,810 --> 00:05:51,120 what license you have loaded on that device. 164 00:05:51,120 --> 00:05:53,160 Then compare the license you loaded 165 00:05:53,160 --> 00:05:54,840 with the features it unlocks. 166 00:05:54,840 --> 00:05:57,390 If the license is not unlocking the features you expected, 167 00:05:57,390 --> 00:05:59,280 you may need to contact the manufacturer 168 00:05:59,280 --> 00:06:00,720 to troubleshoot the issue. 169 00:06:00,720 --> 00:06:03,750 But you may realize, you simply purchased the wrong license 170 00:06:03,750 --> 00:06:05,130 for the features that you need. 171 00:06:05,130 --> 00:06:06,090 And in this case, 172 00:06:06,090 --> 00:06:08,460 you need to work with your organization's purchasing agents 173 00:06:08,460 --> 00:06:09,960 and their contracting professionals 174 00:06:09,960 --> 00:06:11,490 to get the right license procured, 175 00:06:11,490 --> 00:06:13,470 so you can load it up into the device. 176 00:06:13,470 --> 00:06:14,760 Now, this is a common issue 177 00:06:14,760 --> 00:06:16,920 in large bureaucratic organizations 178 00:06:16,920 --> 00:06:17,753 where the people, 179 00:06:17,753 --> 00:06:19,710 who use the things and install the devices, 180 00:06:19,710 --> 00:06:20,820 are not the same ones, 181 00:06:20,820 --> 00:06:23,190 who are empowered to make purchasing decisions. 182 00:06:23,190 --> 00:06:24,750 As a young network administrator, 183 00:06:24,750 --> 00:06:26,580 I remember submitting the requisition forms 184 00:06:26,580 --> 00:06:29,520 to my organization for all the licenses I needed. 185 00:06:29,520 --> 00:06:31,890 I specified that I needed the platinum license. 186 00:06:31,890 --> 00:06:33,187 And the contracting person decided, 187 00:06:33,187 --> 00:06:34,020 "You know what? 188 00:06:34,020 --> 00:06:35,790 The gold license would be just fine, 189 00:06:35,790 --> 00:06:37,950 because it costs 35% less." 190 00:06:37,950 --> 00:06:39,390 Well, guess what? 191 00:06:39,390 --> 00:06:41,100 That contracting person didn't know 192 00:06:41,100 --> 00:06:42,090 that a gold license, 193 00:06:42,090 --> 00:06:43,710 didn't include the three critical features 194 00:06:43,710 --> 00:06:44,910 that we actually needed. 195 00:06:44,910 --> 00:06:46,680 And those features were the whole reason, 196 00:06:46,680 --> 00:06:48,900 we were buying this particular network appliance. 197 00:06:48,900 --> 00:06:50,820 So when we received the license key 198 00:06:50,820 --> 00:06:52,740 and we tried to load it up on the network appliance, 199 00:06:52,740 --> 00:06:55,620 we kept getting the "Feature not licensed" error message. 200 00:06:55,620 --> 00:06:57,360 And it took us almost two days to figure out 201 00:06:57,360 --> 00:07:00,750 that the reason was our organization gave us a gold license 202 00:07:00,750 --> 00:07:03,060 and not a platinum license that we really needed. 203 00:07:03,060 --> 00:07:04,950 So learn from our mistake, 204 00:07:04,950 --> 00:07:06,960 make sure you tell the contract personnel 205 00:07:06,960 --> 00:07:09,300 that substitutions are simply not allowed. 206 00:07:09,300 --> 00:07:10,890 You need this level of license, 207 00:07:10,890 --> 00:07:13,500 or it just won't work for the features you need. 208 00:07:13,500 --> 00:07:16,080 Next, let's discuss BYOD challenges, 209 00:07:16,080 --> 00:07:18,000 or Bring-Your-Own-Device challenges. 210 00:07:18,000 --> 00:07:19,590 Now, I don't want to specifically focus 211 00:07:19,590 --> 00:07:22,590 on security challenges associated with BYOD policies. 212 00:07:22,590 --> 00:07:25,410 Instead, I really want to focus on the networking issues 213 00:07:25,410 --> 00:07:26,430 that you may come across 214 00:07:26,430 --> 00:07:28,950 when you're trying to support a BYOD policy 215 00:07:28,950 --> 00:07:30,660 inside your organization. 216 00:07:30,660 --> 00:07:33,870 Now, BYOD or Bring Your Own Device is this policy 217 00:07:33,870 --> 00:07:35,160 that allows your end users 218 00:07:35,160 --> 00:07:37,680 to bring their own smartphones, tablets, laptops 219 00:07:37,680 --> 00:07:39,840 and other technical devices into work 220 00:07:39,840 --> 00:07:42,180 and use them on your organization's network. 221 00:07:42,180 --> 00:07:44,970 Now, BYOD allows the organization to save money 222 00:07:44,970 --> 00:07:46,800 by not having to purchase all these devices 223 00:07:46,800 --> 00:07:47,820 for the employees. 224 00:07:47,820 --> 00:07:50,220 But instead, they're relying on the employees 225 00:07:50,220 --> 00:07:52,410 to bring their own equipment and their own devices 226 00:07:52,410 --> 00:07:53,520 and then do the business 227 00:07:53,520 --> 00:07:56,580 on those devices using your organization's network. 228 00:07:56,580 --> 00:07:58,740 Now, the biggest challenge with BYOD, 229 00:07:58,740 --> 00:08:00,300 besides securing these devices, 230 00:08:00,300 --> 00:08:02,610 is actually supporting these devices. 231 00:08:02,610 --> 00:08:04,200 When a user brings their own device, 232 00:08:04,200 --> 00:08:07,050 you're no longer supporting one or two models of laptops. 233 00:08:07,050 --> 00:08:07,883 But instead, 234 00:08:07,883 --> 00:08:11,580 you've got 50 or a 100 or 200 different varieties now. 235 00:08:11,580 --> 00:08:14,160 Your employees may bring a Windows 10 Home Edition laptop, 236 00:08:14,160 --> 00:08:16,860 or a MacBook Air or a Chromebook. 237 00:08:16,860 --> 00:08:17,850 And guess what? 238 00:08:17,850 --> 00:08:20,280 You're going to be expected to support all of them. 239 00:08:20,280 --> 00:08:22,590 This is a massive headache and a huge challenge 240 00:08:22,590 --> 00:08:23,700 for support personnel, 241 00:08:23,700 --> 00:08:26,100 like our service desk and our network technicians. 242 00:08:26,100 --> 00:08:28,170 Now, when a device doesn't work properly, 243 00:08:28,170 --> 00:08:29,670 like we want to expect it to, 244 00:08:29,670 --> 00:08:31,590 we have to determine is it the device, 245 00:08:31,590 --> 00:08:33,450 or is it some software the user loaded, 246 00:08:33,450 --> 00:08:36,120 or is it a network issue that we need to solve? 247 00:08:36,120 --> 00:08:38,010 This makes it very challenging. 248 00:08:38,010 --> 00:08:40,020 Honestly, while many organizations think 249 00:08:40,020 --> 00:08:42,720 that implementing a BYOD policy can save them a lot 250 00:08:42,720 --> 00:08:43,553 of money, 251 00:08:43,553 --> 00:08:45,090 because they'll have a reduced capital expenditure 252 00:08:45,090 --> 00:08:46,500 or CapEx cost, 253 00:08:46,500 --> 00:08:48,390 it really just increases your OpEx, 254 00:08:48,390 --> 00:08:49,950 or operational expenditures. 255 00:08:49,950 --> 00:08:53,160 Because now, you're wasting so much time on labor hours 256 00:08:53,160 --> 00:08:56,010 to support and troubleshoot all these different devices. 257 00:08:56,010 --> 00:08:57,900 Another challenge with supporting these devices, 258 00:08:57,900 --> 00:08:59,760 is ensuring the security of your network 259 00:08:59,760 --> 00:09:02,310 and how these devices are going to access your network. 260 00:09:02,310 --> 00:09:03,750 Are you going to let these devices connect 261 00:09:03,750 --> 00:09:05,340 on your wired network connections, 262 00:09:05,340 --> 00:09:07,410 or are you going to make them use wireless? 263 00:09:07,410 --> 00:09:09,450 Will you require that they be registered ahead of time, 264 00:09:09,450 --> 00:09:11,100 so you know what their MAC addresses are 265 00:09:11,100 --> 00:09:13,200 and they can be identified in whitelist, 266 00:09:13,200 --> 00:09:15,540 or are you going to require these BYOD devices 267 00:09:15,540 --> 00:09:17,190 to remain on a separate VLAN? 268 00:09:17,190 --> 00:09:18,023 That way, 269 00:09:18,023 --> 00:09:20,130 they're not going to touch your internal network services 270 00:09:20,130 --> 00:09:20,963 and if they do, 271 00:09:20,963 --> 00:09:22,950 they have to pass through a screened subnet. 272 00:09:22,950 --> 00:09:24,990 All of these are valid questions to consider 273 00:09:24,990 --> 00:09:27,390 as you determine how you're going to support BYOD 274 00:09:27,390 --> 00:09:28,320 on your network, 275 00:09:28,320 --> 00:09:29,430 both operationally 276 00:09:29,430 --> 00:09:32,160 and from a troubleshooting and repair perspective. 277 00:09:32,160 --> 00:09:34,830 Finally, let's talk about hardware failures. 278 00:09:34,830 --> 00:09:37,440 Hardware failures can occur all over your network, 279 00:09:37,440 --> 00:09:40,140 your routers, your switches and your firewalls can fail 280 00:09:40,140 --> 00:09:41,700 for all sorts of reasons, 281 00:09:41,700 --> 00:09:43,740 just like your network clients can. 282 00:09:43,740 --> 00:09:45,600 As you begin to troubleshoot this issue, 283 00:09:45,600 --> 00:09:46,433 you need 284 00:09:46,433 --> 00:09:48,720 to pinpoint both which device is experiencing the failure 285 00:09:48,720 --> 00:09:52,020 and which component on the device has failed. 286 00:09:52,020 --> 00:09:53,970 Once you identify the device that failed, 287 00:09:53,970 --> 00:09:55,740 such as a router that isn't passing traffic 288 00:09:55,740 --> 00:09:57,270 from one subnet to another, 289 00:09:57,270 --> 00:10:00,030 you then need to identify the component that failed. 290 00:10:00,030 --> 00:10:00,863 Most components 291 00:10:00,863 --> 00:10:03,030 on our network devices are field-replaceable, 292 00:10:03,030 --> 00:10:05,370 which means you can swap them out with different components 293 00:10:05,370 --> 00:10:08,520 and get the device back up and operational very quickly. 294 00:10:08,520 --> 00:10:09,360 For example, 295 00:10:09,360 --> 00:10:11,160 if we had one of our dual power supplies fail 296 00:10:11,160 --> 00:10:12,240 in a border router, 297 00:10:12,240 --> 00:10:14,370 we can schedule an emergency maintenance window, 298 00:10:14,370 --> 00:10:16,920 we can power down the device, open up the chassis, 299 00:10:16,920 --> 00:10:18,510 replace the broken power supply 300 00:10:18,510 --> 00:10:20,940 and then return the device to normal operations. 301 00:10:20,940 --> 00:10:23,760 If an interface card or module is broken or defective, 302 00:10:23,760 --> 00:10:25,560 we can simply replace that as well. 303 00:10:25,560 --> 00:10:28,320 And many of these are considered hot pluggable modules. 304 00:10:28,320 --> 00:10:30,690 So if you have an SFP+ module that fails, 305 00:10:30,690 --> 00:10:31,800 we can simply replace it 306 00:10:31,800 --> 00:10:33,600 without even shutting down the network device, 307 00:10:33,600 --> 00:10:35,130 or taking it offline. 308 00:10:35,130 --> 00:10:37,110 If a client or server on the other hand is found 309 00:10:37,110 --> 00:10:39,300 to have a defective component or hardware failure, 310 00:10:39,300 --> 00:10:41,640 we can work with our CompTIA A+ technicians 311 00:10:41,640 --> 00:10:42,870 to solve those issues 312 00:10:42,870 --> 00:10:45,270 by replacing the associate hardware components. 313 00:10:45,270 --> 00:10:47,820 Normally, with a defective or failed piece of hardware, 314 00:10:47,820 --> 00:10:49,920 the fastest way to restore service is simply 315 00:10:49,920 --> 00:10:51,960 to replace the component that's failed us. 316 00:10:51,960 --> 00:10:52,830 In some cases, 317 00:10:52,830 --> 00:10:55,110 such as a failed motherboard on a router or switch, 318 00:10:55,110 --> 00:10:57,360 you may need to replace the entire device. 319 00:10:57,360 --> 00:10:58,350 In these cases, 320 00:10:58,350 --> 00:10:59,850 you should get a spare switch or router 321 00:10:59,850 --> 00:11:01,140 from your supply closet, 322 00:11:01,140 --> 00:11:02,430 mount it into the rack, 323 00:11:02,430 --> 00:11:04,860 load up your backup configurations from the failed device 324 00:11:04,860 --> 00:11:06,600 and put that into the replacement device 325 00:11:06,600 --> 00:11:08,640 and then reconnect all the cables to it 326 00:11:08,640 --> 00:11:11,850 and finally, restore service using your new device. 327 00:11:11,850 --> 00:11:14,370 Then you could take the failed device out of the rack, 328 00:11:14,370 --> 00:11:16,320 return it to the manufacturer for repair 329 00:11:16,320 --> 00:11:18,780 and then it can become part of your spares in the future 330 00:11:18,780 --> 00:11:20,040 if it's under warranty, 331 00:11:20,040 --> 00:11:21,780 or you could dispose of it properly 332 00:11:21,780 --> 00:11:23,930 if it's reached the end of its useful life.