1 1 00:00:00,320 --> 00:00:01,720 Other issues. 2 2 00:00:01,720 --> 00:00:04,510 In this video we're going to discuss some other issues 3 3 00:00:04,510 --> 00:00:05,940 you may need to troubleshoot. 4 4 00:00:05,940 --> 00:00:09,130 Things like low optical link budgets, certificate issues, 5 5 00:00:09,130 --> 00:00:11,900 license feature issues, BYOD challenges 6 6 00:00:11,900 --> 00:00:13,360 and hardware failures. 7 7 00:00:13,360 --> 00:00:16,240 First, let's talk about low optical link budgets. 8 8 00:00:16,240 --> 00:00:19,090 And what exactly is an optical link budget? 9 9 00:00:19,090 --> 00:00:21,760 Now an optical link budget is a calculation that considers 10 10 00:00:21,760 --> 00:00:24,020 all the anticipated losses along the length 11 11 00:00:24,020 --> 00:00:25,800 of a fiber optic connection. 12 12 00:00:25,800 --> 00:00:27,170 This is important to understand. 13 13 00:00:27,170 --> 00:00:28,840 Because the light signal that's going across 14 14 00:00:28,840 --> 00:00:31,410 that fiber optic cable will lose signal strength 15 15 00:00:31,410 --> 00:00:33,340 as it travels down this cable. 16 16 00:00:33,340 --> 00:00:36,040 Now this occurs naturally due to the distance of the cable, 17 17 00:00:36,040 --> 00:00:38,260 as well as from losses due to multiplexing, 18 18 00:00:38,260 --> 00:00:41,290 benzing your cable, imperfect connections, patches 19 19 00:00:41,290 --> 00:00:44,400 or splices that happen along the fiber optic cable. 20 20 00:00:44,400 --> 00:00:46,870 If you experience a low optical link budget, 21 21 00:00:46,870 --> 00:00:49,180 your fiber connection will experience issues 22 22 00:00:49,180 --> 00:00:51,110 such as reduced transmission efficiency, 23 23 00:00:51,110 --> 00:00:52,350 slower connection speeds 24 24 00:00:52,350 --> 00:00:54,530 or even downtime on that connection. 25 25 00:00:54,530 --> 00:00:57,000 To measure the condition of your fiber optic connection, 26 26 00:00:57,000 --> 00:00:59,570 you're going to use an optical time domain reflectometer 27 27 00:00:59,570 --> 00:01:01,600 to measure the amount of losses or reflections 28 28 00:01:01,600 --> 00:01:03,480 that are occurring in the connection. 29 29 00:01:03,480 --> 00:01:06,040 This reading from the optical time domain reflectometer 30 30 00:01:06,040 --> 00:01:08,720 is going to be reported in decibels per kilometer. 31 31 00:01:08,720 --> 00:01:11,710 And this indicates how much attenuation and degradation 32 32 00:01:11,710 --> 00:01:14,120 is occurring over the length of that connection. 33 33 00:01:14,120 --> 00:01:18,110 Normally, you should experience 0.25 decibels per kilometer 34 34 00:01:18,110 --> 00:01:19,910 for a standard fiber optic cable. 35 35 00:01:19,910 --> 00:01:21,790 But if you experience a higher rate than this, 36 36 00:01:21,790 --> 00:01:24,430 then you may have a low optical link budget. 37 37 00:01:24,430 --> 00:01:25,920 To calculate your link budget. 38 38 00:01:25,920 --> 00:01:28,440 You simply take the receiver's power budget or how much 39 39 00:01:28,440 --> 00:01:30,290 initial signal you're going to be transmitting out, 40 40 00:01:30,290 --> 00:01:33,270 and then you subtract any multiplexing and demultiplexing 41 41 00:01:33,270 --> 00:01:35,870 losses as well as losses from the fiber itself 42 42 00:01:35,870 --> 00:01:38,470 that's caused by those distances and the imperfections. 43 43 00:01:38,470 --> 00:01:40,980 And any losses from the connectors or patch panels 44 44 00:01:40,980 --> 00:01:42,560 that are being used as well. 45 45 00:01:42,560 --> 00:01:45,610 Now, this will give you the total optical link budget. 46 46 00:01:45,610 --> 00:01:48,560 For example, let's say I designed a fiber optic circuit 47 47 00:01:48,560 --> 00:01:50,740 with a receiver that can sense light received between 48 48 00:01:50,740 --> 00:01:53,550 negative seven decibels and negative 23 decibels. 49 49 00:01:53,550 --> 00:01:56,600 And I send the signal out at positive five decibels. 50 50 00:01:56,600 --> 00:01:59,020 Now, if I only have a loss of 20 decibels 51 51 00:01:59,020 --> 00:02:00,770 due to the distance, the connectors 52 52 00:02:00,770 --> 00:02:02,200 and a splice in that cable. 53 53 00:02:02,200 --> 00:02:04,160 The is going to be able to pick up that signal 54 54 00:02:04,160 --> 00:02:07,110 because I still have negative 15 decibels of light signal 55 55 00:02:07,110 --> 00:02:09,060 being received at that distant end. 56 56 00:02:09,060 --> 00:02:11,830 And negative 15 is in between negative seven 57 57 00:02:11,830 --> 00:02:13,390 and negative 23. 58 58 00:02:13,390 --> 00:02:15,820 On the other hand, if the fiber connection was broken 59 59 00:02:15,820 --> 00:02:18,490 and somebody went to repair it by splicing that connection, 60 60 00:02:18,490 --> 00:02:20,340 maybe they did a really bad job of it. 61 61 00:02:20,340 --> 00:02:23,250 And adds an extra 25 decibels of signal loss. 62 62 00:02:23,250 --> 00:02:25,730 Now I'm going to transmit at the same five decibels 63 63 00:02:25,730 --> 00:02:26,890 that I was before. 64 64 00:02:26,890 --> 00:02:29,680 But I'm losing 15 decibels for distance 65 65 00:02:29,680 --> 00:02:30,990 in that first splice. 66 66 00:02:30,990 --> 00:02:33,270 And now because of this poor second splice, 67 67 00:02:33,270 --> 00:02:35,470 I'm losing another 25 decibels. 68 68 00:02:35,470 --> 00:02:38,010 This brings my total value on the receiving end 69 69 00:02:38,010 --> 00:02:39,850 to negative 35 decibels. 70 70 00:02:39,850 --> 00:02:42,500 And that means the receiver can't pick up that signal 71 71 00:02:42,500 --> 00:02:45,300 because it can only sense the signals between negative seven 72 72 00:02:45,300 --> 00:02:46,810 and negative 23 decibels. 73 73 00:02:46,810 --> 00:02:50,410 And negative 35 is far too weak for the receiver to see it. 74 74 00:02:50,410 --> 00:02:53,090 Now, we're going to have a broken fiber link essentially, 75 75 00:02:53,090 --> 00:02:55,690 because we have a low optical link budget level. 76 76 00:02:55,690 --> 00:02:57,900 So, what can we do to fix this? 77 77 00:02:57,900 --> 00:03:00,500 Well, we can either increase the power of the transmitter 78 78 00:03:00,500 --> 00:03:03,720 to say plus 20 decibels instead of plus five decibels. 79 79 00:03:03,720 --> 00:03:06,640 Or we can have somebody go back and try to do a better job 80 80 00:03:06,640 --> 00:03:08,090 of splicing that cable. 81 81 00:03:08,090 --> 00:03:10,410 Now, this isn't a very realistic example 82 82 00:03:10,410 --> 00:03:12,840 because most professional splices will only cause a loss 83 83 00:03:12,840 --> 00:03:15,560 of 0.1 or 0.2 decibels. 84 84 00:03:15,560 --> 00:03:17,870 But hopefully you're getting the idea of how low optical 85 85 00:03:17,870 --> 00:03:19,990 link budget can work and negatively affect 86 86 00:03:19,990 --> 00:03:21,510 your fiber networks. 87 87 00:03:21,510 --> 00:03:23,210 Next, we have certificate issues 88 88 00:03:23,210 --> 00:03:25,350 that can cause network issues for us as well. 89 89 00:03:25,350 --> 00:03:27,640 A digital certificate is used as a credential 90 90 00:03:27,640 --> 00:03:29,700 to facilitate the verification of identities 91 91 00:03:29,700 --> 00:03:32,020 between users inside of a transaction. 92 92 00:03:32,020 --> 00:03:33,800 For example, when you attempt to connect 93 93 00:03:33,800 --> 00:03:36,310 to an e-commerce site over HTTPS, 94 94 00:03:36,310 --> 00:03:38,670 your network client uses digital certificates 95 95 00:03:38,670 --> 00:03:40,720 to validate the server's identity and decide 96 96 00:03:40,720 --> 00:03:43,180 if it can really trust that server when sending sensitive 97 97 00:03:43,180 --> 00:03:44,660 information over to it. 98 98 00:03:44,660 --> 00:03:47,000 The most common certificate issues are going to occur 99 99 00:03:47,000 --> 00:03:49,670 on a websites SSL or TLS certificate 100 100 00:03:49,670 --> 00:03:51,820 when it's displaying as untrusted. 101 101 00:03:51,820 --> 00:03:54,030 Now, this occurs for one of three reasons. 102 102 00:03:54,030 --> 00:03:56,250 It can be that the digital certificate is not signed 103 103 00:03:56,250 --> 00:03:57,940 by a trusted certificate authority, 104 104 00:03:57,940 --> 00:03:59,940 the certificate itself has already expired 105 105 00:03:59,940 --> 00:04:02,420 or the server didn't have a certificate associated 106 106 00:04:02,420 --> 00:04:04,370 with a trusted route certificate. 107 107 00:04:04,370 --> 00:04:06,870 Now, regardless of which of these three things is happening, 108 108 00:04:06,870 --> 00:04:08,820 the end result is going to be the same. 109 109 00:04:08,820 --> 00:04:11,130 Your client's browser is not going to show a secure 110 110 00:04:11,130 --> 00:04:14,320 connection over HTTPS because it's web browser 111 111 00:04:14,320 --> 00:04:17,540 and the server are not communicating over a secure tunnel. 112 112 00:04:17,540 --> 00:04:19,270 Now, in either of these cases, 113 113 00:04:19,270 --> 00:04:21,420 you can't solve the issue for your network clients 114 114 00:04:21,420 --> 00:04:23,260 because you don't own that web server. 115 115 00:04:23,260 --> 00:04:25,710 But if you were the one who owned that web server, 116 116 00:04:25,710 --> 00:04:27,900 then it becomes your problem to fix. 117 117 00:04:27,900 --> 00:04:30,700 Now in this case, you need to purchase a digital certificate 118 118 00:04:30,700 --> 00:04:33,160 from a trusted certificate authority and install it. 119 119 00:04:33,160 --> 00:04:36,030 Or you need to renew your expired digital certificate. 120 120 00:04:36,030 --> 00:04:38,430 Or you need to install a certificate from a trusted 121 121 00:04:38,430 --> 00:04:40,730 certificate authority with a valid route certificate 122 122 00:04:40,730 --> 00:04:42,220 on your server. 123 123 00:04:42,220 --> 00:04:44,549 In addition to using digital certificates with HTTPS 124 124 00:04:44,549 --> 00:04:45,550 websites, 125 125 00:04:45,550 --> 00:04:48,310 we also can use digital certificates inside of our networks 126 126 00:04:48,310 --> 00:04:52,610 for network authentication using 802.1X with EAP. 127 127 00:04:52,610 --> 00:04:55,020 In these cases, your security team's going to run 128 128 00:04:55,020 --> 00:04:57,120 your organizations own certificate authority 129 129 00:04:57,120 --> 00:04:59,370 to create these digital certificates and issue them 130 130 00:04:59,370 --> 00:05:01,410 to the network clients and the servers. 131 131 00:05:01,410 --> 00:05:02,243 Again, 132 132 00:05:02,243 --> 00:05:04,300 if you're having issues with these digital certificates, 133 133 00:05:04,300 --> 00:05:06,940 you need to ensure they're trusted, that they're not expired 134 134 00:05:06,940 --> 00:05:09,350 and that they're installed properly on the network devices 135 135 00:05:09,350 --> 00:05:10,930 and the network clients. 136 136 00:05:10,930 --> 00:05:13,500 Next, we need to talk about licensed feature issues 137 137 00:05:13,500 --> 00:05:15,120 that could arise in your networks. 138 138 00:05:15,120 --> 00:05:17,520 Sometimes when troubleshooting issues in your network, 139 139 00:05:17,520 --> 00:05:20,210 you may come across an error message such as error, 140 140 00:05:20,210 --> 00:05:21,690 feature not licensed. 141 141 00:05:21,690 --> 00:05:23,110 Now as you can see in this example 142 142 00:05:23,110 --> 00:05:25,170 from a NetScaler VPX appliance, 143 143 00:05:25,170 --> 00:05:27,210 there are many different features that are enabled 144 144 00:05:27,210 --> 00:05:29,870 or disabled based upon the license has been purchased 145 145 00:05:29,870 --> 00:05:31,290 by this organization. 146 146 00:05:31,290 --> 00:05:33,860 For example, the license they have purchased will allow them 147 147 00:05:33,860 --> 00:05:36,010 to do load balancing and content switching. 148 148 00:05:36,010 --> 00:05:38,820 But it does not support global server load balancing 149 149 00:05:38,820 --> 00:05:39,910 or clustering. 150 150 00:05:39,910 --> 00:05:42,360 This is a different feature set that requires a different 151 151 00:05:42,360 --> 00:05:44,140 and more expensive license. 152 152 00:05:44,140 --> 00:05:46,570 Now if you get an error concerning a particular license 153 153 00:05:46,570 --> 00:05:48,830 feature in this or another network device, 154 154 00:05:48,830 --> 00:05:50,860 you first need to determine what license 155 155 00:05:50,860 --> 00:05:52,500 you have loaded on that device. 156 156 00:05:52,500 --> 00:05:54,560 Then compare the license you loaded 157 157 00:05:54,560 --> 00:05:56,190 with the features it unlocks. 158 158 00:05:56,190 --> 00:05:58,770 If the license is unlocking the features you expected, 159 159 00:05:58,770 --> 00:06:01,300 you may need to contact the manufacturer to troubleshoot 160 160 00:06:01,300 --> 00:06:02,133 the issue. 161 161 00:06:02,133 --> 00:06:05,110 But you may realize you simply purchase the wrong license 162 162 00:06:05,110 --> 00:06:06,510 for the features that you need. 163 163 00:06:06,510 --> 00:06:07,480 And in this case, 164 164 00:06:07,480 --> 00:06:09,830 you need to work with your organization's purchasing agents 165 165 00:06:09,830 --> 00:06:12,330 and their contracting professionals to get the right license 166 166 00:06:12,330 --> 00:06:14,840 procured so you can load it up into the device. 167 167 00:06:14,840 --> 00:06:17,033 Now this is a common issue in large bureaucratic 168 168 00:06:17,033 --> 00:06:19,810 organizations where the people who use the things 169 169 00:06:19,810 --> 00:06:22,210 and install the devices are not the same ones 170 170 00:06:22,210 --> 00:06:24,560 who are empowered to make purchasing decisions. 171 171 00:06:24,560 --> 00:06:26,140 As a young network administrator. 172 172 00:06:26,140 --> 00:06:27,940 I remember submitting the requisition forms 173 173 00:06:27,940 --> 00:06:30,910 to my organization for all the licenses I needed. 174 174 00:06:30,910 --> 00:06:33,210 I specified that I needed the platinum license. 175 175 00:06:33,210 --> 00:06:35,340 And the contracting person decided, you know what, 176 176 00:06:35,340 --> 00:06:37,170 the gold license would be just fine 177 177 00:06:37,170 --> 00:06:39,360 because it costs 35% less. 178 178 00:06:39,360 --> 00:06:40,760 Well, guess what? 179 179 00:06:40,760 --> 00:06:43,480 That contracting person didn't know that a gold license 180 180 00:06:43,480 --> 00:06:45,090 didn't include the three critical features 181 181 00:06:45,090 --> 00:06:46,250 that we actually needed. 182 182 00:06:46,250 --> 00:06:48,600 And those features were the whole reason we were buying 183 183 00:06:48,600 --> 00:06:50,260 this particular network appliance. 184 184 00:06:50,260 --> 00:06:52,170 So, when we received the license key 185 185 00:06:52,170 --> 00:06:54,140 and we tried to load it up on the network appliance, 186 186 00:06:54,140 --> 00:06:57,000 we kept getting the feature not licensed error message. 187 187 00:06:57,000 --> 00:06:58,760 And it took us almost two days to figure out 188 188 00:06:58,760 --> 00:07:02,100 that the reason was our organization gave us a gold license 189 189 00:07:02,100 --> 00:07:04,420 and not a platinum license that we really needed. 190 190 00:07:04,420 --> 00:07:06,350 So learn from our mistake. 191 191 00:07:06,350 --> 00:07:08,330 Make sure you tell the contract personnel 192 192 00:07:08,330 --> 00:07:10,690 that substitutions are simply not allowed. 193 193 00:07:10,690 --> 00:07:13,260 You need this level of license or just won't work 194 194 00:07:13,260 --> 00:07:14,890 for the features you need. 195 195 00:07:14,890 --> 00:07:17,460 Next let's discuss BYOD challenges 196 196 00:07:17,460 --> 00:07:19,410 or bring your own device challenges. 197 197 00:07:19,410 --> 00:07:21,540 Now I don't want to specifically focus on security 198 198 00:07:21,540 --> 00:07:23,950 challenges associated with BYOB policies. 199 199 00:07:23,950 --> 00:07:26,410 Because we've already talked about that in other videos. 200 200 00:07:26,410 --> 00:07:29,260 Instead, I really want to focus on the networking issues 201 201 00:07:29,260 --> 00:07:31,240 that you may come across when you're trying to support 202 202 00:07:31,240 --> 00:07:34,510 a BYOB policy inside your organization. 203 203 00:07:34,510 --> 00:07:37,700 Now BYOD or bring your own device is this policy 204 204 00:07:37,700 --> 00:07:40,290 that allows your end users to bring their own smartphones, 205 205 00:07:40,290 --> 00:07:43,640 tablets, laptops and other technical devices into work 206 206 00:07:43,640 --> 00:07:46,000 and use them on your organization's network. 207 207 00:07:46,000 --> 00:07:48,820 Now BYOB allows the organization to save money 208 208 00:07:48,820 --> 00:07:50,650 by not having to purchase all these devices 209 209 00:07:50,650 --> 00:07:51,660 for the employees. 210 210 00:07:51,660 --> 00:07:54,070 But instead they're relying on the employees 211 211 00:07:54,070 --> 00:07:56,240 to bring their own equipment and their own devices 212 212 00:07:56,240 --> 00:07:58,410 and then do the business on those devices 213 213 00:07:58,410 --> 00:08:00,410 using your organization's network. 214 214 00:08:00,410 --> 00:08:02,550 Now the biggest challenge with BYOD 215 215 00:08:02,550 --> 00:08:04,130 besides securing these devices, 216 216 00:08:04,130 --> 00:08:06,450 is actually supporting these devices. 217 217 00:08:06,450 --> 00:08:08,030 When a user brings their own device, 218 218 00:08:08,030 --> 00:08:10,890 you're no longer supporting one or two models of laptops, 219 219 00:08:10,890 --> 00:08:13,130 but instead you've got 50 or 100 220 220 00:08:13,130 --> 00:08:15,410 or 200 different varieties now. 221 221 00:08:15,410 --> 00:08:18,010 Your employees may bring a Windows 10 Home Edition laptop 222 222 00:08:18,010 --> 00:08:20,700 or a MacBook Air or a Chromebook. 223 223 00:08:20,700 --> 00:08:21,690 And guess what, 224 224 00:08:21,690 --> 00:08:24,120 you're going to be expected to support all of them. 225 225 00:08:24,120 --> 00:08:26,430 This is a massive headache and a huge challenge 226 226 00:08:26,430 --> 00:08:27,540 for support personnel, 227 227 00:08:27,540 --> 00:08:29,940 like our service desk and our network technicians. 228 228 00:08:29,940 --> 00:08:32,000 Now, when a device doesn't work properly 229 229 00:08:32,000 --> 00:08:33,490 like we want to expect it to, 230 230 00:08:33,490 --> 00:08:35,420 we have to determine is it the device 231 231 00:08:35,420 --> 00:08:37,260 or is it some software the user loaded 232 232 00:08:37,260 --> 00:08:39,950 or is it a network issue that we need to solve? 233 233 00:08:39,950 --> 00:08:41,850 This makes it very challenging. 234 234 00:08:41,850 --> 00:08:44,470 Honestly, well many organizations think that implementing 235 235 00:08:44,470 --> 00:08:47,040 a BYOB policy can save them a lot of money 236 236 00:08:47,040 --> 00:08:48,940 because they'll have a reduced capital expenditure 237 237 00:08:48,940 --> 00:08:50,320 or CapEx costs. 238 238 00:08:50,320 --> 00:08:52,240 It really just increases your OPEX 239 239 00:08:52,240 --> 00:08:54,770 or operational expenditures because now you're wasting 240 240 00:08:54,770 --> 00:08:58,020 so much time on labor hours to support and troubleshoot 241 241 00:08:58,020 --> 00:08:59,840 all these different devices. 242 242 00:08:59,840 --> 00:09:02,190 Another challenge with supporting these devices is ensuring 243 243 00:09:02,190 --> 00:09:04,490 the security of your network and how these devices 244 244 00:09:04,490 --> 00:09:06,160 are going to access your network. 245 245 00:09:06,160 --> 00:09:07,570 Are you going to let these devices connect 246 246 00:09:07,570 --> 00:09:09,150 on your wired network connections 247 247 00:09:09,150 --> 00:09:11,240 or are you going to make them use wireless? 248 248 00:09:11,240 --> 00:09:13,290 We require that they be registered ahead of time 249 249 00:09:13,290 --> 00:09:15,340 so you know what their MAC addresses are and they can be 250 250 00:09:15,340 --> 00:09:16,670 identified in waitlist. 251 251 00:09:16,670 --> 00:09:19,380 Or are you going to require these BYOD devices 252 252 00:09:19,380 --> 00:09:21,030 to remain on a separate VLAN? 253 253 00:09:21,030 --> 00:09:23,270 That way they're not going to touch your internal network 254 254 00:09:23,270 --> 00:09:24,690 services, and if they do, 255 255 00:09:24,690 --> 00:09:26,780 they have to pass through a screened sub-net. 256 256 00:09:26,780 --> 00:09:28,810 All of these are valid questions to consider 257 257 00:09:28,810 --> 00:09:31,230 as you determine how you're going to support BYOB 258 258 00:09:31,230 --> 00:09:32,170 on your network, 259 259 00:09:32,170 --> 00:09:34,250 both operationally and from a troubleshooting 260 260 00:09:34,250 --> 00:09:35,960 and repair perspective. 261 261 00:09:35,960 --> 00:09:38,660 Finally, let's talk about hardware failures. 262 262 00:09:38,660 --> 00:09:41,270 Hardware failures can occur all over your network. 263 263 00:09:41,270 --> 00:09:43,550 Your routers, your switches and your firewalls 264 264 00:09:43,550 --> 00:09:45,520 can fail for all sorts of reasons 265 265 00:09:45,520 --> 00:09:47,560 just like your network clients can. 266 266 00:09:47,560 --> 00:09:49,420 As you begin to troubleshoot this issue, 267 267 00:09:49,420 --> 00:09:52,040 you need to pinpoint both which device is experiencing 268 268 00:09:52,040 --> 00:09:55,840 the failure and which component on the device has failed. 269 269 00:09:55,840 --> 00:09:57,770 Once you identify the device that failed, 270 270 00:09:57,770 --> 00:09:59,570 such as a router that isn't passing traffic 271 271 00:09:59,570 --> 00:10:01,080 from one subnet to another. 272 272 00:10:01,080 --> 00:10:03,870 You then need to identify the component that failed. 273 273 00:10:03,870 --> 00:10:05,540 Most components on our network devices 274 274 00:10:05,540 --> 00:10:06,870 are field replaceable. 275 275 00:10:06,870 --> 00:10:09,120 Which means you can swap them out with different components 276 276 00:10:09,120 --> 00:10:12,340 and get the device back up and operational very quickly. 277 277 00:10:12,340 --> 00:10:14,980 For example, if we had one of our dual power supplies fail 278 278 00:10:14,980 --> 00:10:16,070 in a border router, 279 279 00:10:16,070 --> 00:10:18,210 we can schedule an emergency maintenance window. 280 280 00:10:18,210 --> 00:10:20,740 We can power down the device, open up the chassis, 281 281 00:10:20,740 --> 00:10:22,320 replace the broken power supply 282 282 00:10:22,320 --> 00:10:24,760 and then return the device to normal operations. 283 283 00:10:24,760 --> 00:10:27,610 If an interface card or module is broken or defective, 284 284 00:10:27,610 --> 00:10:29,370 we can simply replace that as well. 285 285 00:10:29,370 --> 00:10:32,140 And many of these are considered hot pluggable modules. 286 286 00:10:32,140 --> 00:10:34,520 So if you have an SFP plus module that fails, 287 287 00:10:34,520 --> 00:10:36,600 we can simply replace it without even shutting down 288 288 00:10:36,600 --> 00:10:38,940 the network device or taking it offline. 289 289 00:10:38,940 --> 00:10:40,560 If a client or server on the other hand 290 290 00:10:40,560 --> 00:10:43,150 is found to have a defective component or hardware failure, 291 291 00:10:43,150 --> 00:10:45,480 we can work with our CompTIA A+ technicians 292 292 00:10:45,480 --> 00:10:47,730 to solve those issues by replacing the associated 293 293 00:10:47,730 --> 00:10:49,100 hardware components. 294 294 00:10:49,100 --> 00:10:51,640 Normally with a defective or field piece of hardware, 295 295 00:10:51,640 --> 00:10:54,210 the fastest way to restore service is simply to replace 296 296 00:10:54,210 --> 00:10:55,770 the component that's failed us. 297 297 00:10:55,770 --> 00:10:56,640 In some cases, 298 298 00:10:56,640 --> 00:10:58,930 such as a failed motherboard on a router or switch, 299 299 00:10:58,930 --> 00:11:01,160 you may need to replace the entire device. 300 300 00:11:01,160 --> 00:11:03,670 In these cases, you should get a spare switch or router 301 301 00:11:03,670 --> 00:11:06,270 from your supply closet, mounted into the rack, 302 302 00:11:06,270 --> 00:11:08,750 load up your backup configurations from the failed device 303 303 00:11:08,750 --> 00:11:10,440 and put that into the replacement device 304 304 00:11:10,440 --> 00:11:12,450 and then reconnect all the cables to it. 305 305 00:11:12,450 --> 00:11:15,690 And finally restore service using your new device. 306 306 00:11:15,690 --> 00:11:18,200 Then you can take the field device out of the rack, 307 307 00:11:18,200 --> 00:11:20,140 return it to the manufacturer for repair 308 308 00:11:20,140 --> 00:11:22,620 and then it can become part of your spares in the future 309 309 00:11:22,620 --> 00:11:25,620 if it's under warranty or you could dispose of it properly 310 310 00:11:25,620 --> 00:11:27,770 if it's reached the end of its useful life.