1 00:00:00,000 --> 00:00:00,930 In this lesson, 2 00:00:00,930 --> 00:00:03,600 we're going to cover VLAN configurations. 3 00:00:03,600 --> 00:00:05,760 Virtual local area networks or VLANs 4 00:00:05,760 --> 00:00:06,960 are a fundamental aspect 5 00:00:06,960 --> 00:00:09,240 of our modern network designs and architecture 6 00:00:09,240 --> 00:00:11,160 because they offer us with more flexibility, 7 00:00:11,160 --> 00:00:13,080 improved performance, and enhanced security 8 00:00:13,080 --> 00:00:14,910 over our traditional networks. 9 00:00:14,910 --> 00:00:16,590 To effectively use A VLAN though, 10 00:00:16,590 --> 00:00:18,390 you must properly configure it. 11 00:00:18,390 --> 00:00:19,470 So in this lesson, 12 00:00:19,470 --> 00:00:20,303 we're going to take a look 13 00:00:20,303 --> 00:00:21,930 at some common interface configurations 14 00:00:21,930 --> 00:00:22,830 that you should consider 15 00:00:22,830 --> 00:00:25,620 when setting up or managing a VLAN in your network, 16 00:00:25,620 --> 00:00:28,020 including 802.1Q tagging, 17 00:00:28,020 --> 00:00:28,853 the native VLAN, 18 00:00:28,853 --> 00:00:31,500 a voice VLAN, link aggregation, 19 00:00:31,500 --> 00:00:33,930 and speed and duplex configurations. 20 00:00:33,930 --> 00:00:36,837 Now, first we have 802.1Q tagging. 21 00:00:36,837 --> 00:00:41,247 802.1Q tagging is a crucial element in VLAN configurations. 22 00:00:41,247 --> 00:00:45,540 802.1Q tagging, also known simply as VLAN tagging, 23 00:00:45,540 --> 00:00:47,400 refers to the IEEE standard 24 00:00:47,400 --> 00:00:49,800 that facilitates the management of multiple VLANs 25 00:00:49,800 --> 00:00:51,330 on a single network. 26 00:00:51,330 --> 00:00:53,850 VLAN tagging works by inserting a VLAN tag 27 00:00:53,850 --> 00:00:55,170 into an ethernet frame 28 00:00:55,170 --> 00:00:56,790 to enable your switches to identify 29 00:00:56,790 --> 00:00:59,430 and forward the frames to the proper VLAN. 30 00:00:59,430 --> 00:01:03,120 Each tag is going to contain a VLAN identifier or VID, 31 00:01:03,120 --> 00:01:04,170 which is used by our switches 32 00:01:04,170 --> 00:01:06,630 to distinguish one VLAN from another. 33 00:01:06,630 --> 00:01:08,910 This will allow for trunking to occur as well. 34 00:01:08,910 --> 00:01:09,900 Now, when I talk about trunking, 35 00:01:09,900 --> 00:01:12,060 trunking is just the transmission of traffic 36 00:01:12,060 --> 00:01:13,050 from different VLANs 37 00:01:13,050 --> 00:01:15,420 across the same physical network infrastructure 38 00:01:15,420 --> 00:01:17,490 while keeping that traffic from each VLAN 39 00:01:17,490 --> 00:01:19,290 separate and secure. 40 00:01:19,290 --> 00:01:21,090 In many large enterprise networks, 41 00:01:21,090 --> 00:01:23,160 we're going to use 802.1Q tagging 42 00:01:23,160 --> 00:01:24,630 to create logical separations 43 00:01:24,630 --> 00:01:26,070 between our different departments, 44 00:01:26,070 --> 00:01:28,200 like human resources and accounting, 45 00:01:28,200 --> 00:01:30,450 so that each one is put into a separate VLAN 46 00:01:30,450 --> 00:01:32,220 and they can each have different security measures 47 00:01:32,220 --> 00:01:34,260 put into place to protect each department 48 00:01:34,260 --> 00:01:37,140 against threats that are specific to their daily work. 49 00:01:37,140 --> 00:01:38,580 Whenever a data packet originates 50 00:01:38,580 --> 00:01:40,860 from the HR department's network, for example, 51 00:01:40,860 --> 00:01:43,050 it's going to be tagged with a unique VLAN ID 52 00:01:43,050 --> 00:01:44,910 for the human resources VLAN 53 00:01:44,910 --> 00:01:47,430 as that data leaves the departmental switch. 54 00:01:47,430 --> 00:01:49,140 Whenever these packets traverse the network 55 00:01:49,140 --> 00:01:50,790 through the shared switches and links, 56 00:01:50,790 --> 00:01:53,790 the 802.1Q tag that was applied to the frame 57 00:01:53,790 --> 00:01:54,942 will ensure that they remain isolated 58 00:01:54,942 --> 00:01:57,600 from the finance department's traffic as well. 59 00:01:57,600 --> 00:01:59,490 Similarly, the finance department's traffic 60 00:01:59,490 --> 00:02:01,740 will also be tagged with a different VID 61 00:02:01,740 --> 00:02:04,980 to signify that it belongs to the finance VLAN instead. 62 00:02:04,980 --> 00:02:06,090 This type of tagging 63 00:02:06,090 --> 00:02:08,160 is going to help to maintain data segregation 64 00:02:08,160 --> 00:02:10,350 as well as enabling the use of our network resources 65 00:02:10,350 --> 00:02:12,600 by allowing multiple VLANs to coexist 66 00:02:12,600 --> 00:02:15,570 on the same physical network infrastructure devices. 67 00:02:15,570 --> 00:02:17,940 Second, we have the native VLAN. 68 00:02:17,940 --> 00:02:20,580 The native VLAN is the one VLAN on a trunk port 69 00:02:20,580 --> 00:02:23,100 that does not get tagged with a VLAN identifier 70 00:02:23,100 --> 00:02:25,770 when the frames are being passed over that trunk link. 71 00:02:25,770 --> 00:02:29,160 Essentially, this is the default VLAN for untagged frames, 72 00:02:29,160 --> 00:02:30,720 and you'll often hear the native VLAN 73 00:02:30,720 --> 00:02:33,600 also called the default VLAN because of this. 74 00:02:33,600 --> 00:02:35,370 Whenever a switch received an untagged frame 75 00:02:35,370 --> 00:02:36,390 on a trunk port, 76 00:02:36,390 --> 00:02:39,060 it's going to assign that frame to the native VLAN. 77 00:02:39,060 --> 00:02:41,130 Now, if you're transferring data from multiple VLANs 78 00:02:41,130 --> 00:02:43,260 over a single trunk link between your switches, 79 00:02:43,260 --> 00:02:45,600 you're also going to need to interact with devices or networks 80 00:02:45,600 --> 00:02:47,850 that may not understand VLAN tags. 81 00:02:47,850 --> 00:02:48,780 And in this case, 82 00:02:48,780 --> 00:02:51,360 you can assign that type of data to the native VLAN 83 00:02:51,360 --> 00:02:54,060 to increase your capability and compatibility. 84 00:02:54,060 --> 00:02:55,980 So let's pretend that you have a network 85 00:02:55,980 --> 00:02:56,970 that you're going to be designing 86 00:02:56,970 --> 00:02:59,550 that has to support some older legacy network devices 87 00:02:59,550 --> 00:03:02,070 that simply can't support VLAN tagging. 88 00:03:02,070 --> 00:03:04,800 These legacy devices are going to be sending untagged traffic 89 00:03:04,800 --> 00:03:07,110 to your newer, more modern network switches. 90 00:03:07,110 --> 00:03:09,300 And when the traffic reaches those modern switches, 91 00:03:09,300 --> 00:03:11,160 the trunk port on those modern switches 92 00:03:11,160 --> 00:03:13,560 is going to be designed to assign every piece of traffic 93 00:03:13,560 --> 00:03:15,240 to a specific VLAN. 94 00:03:15,240 --> 00:03:16,080 Since the data received 95 00:03:16,080 --> 00:03:18,030 from the legacy switches is untagged, 96 00:03:18,030 --> 00:03:20,100 the modern switch will simply tag that traffic 97 00:03:20,100 --> 00:03:22,560 as part of the native VLAN when it's received, 98 00:03:22,560 --> 00:03:24,690 and then it'll continue to pass that traffic 99 00:03:24,690 --> 00:03:27,300 along the native VLANs default pathway. 100 00:03:27,300 --> 00:03:30,060 For example, if your modern switch uses VLAN 10 101 00:03:30,060 --> 00:03:31,440 as its native VLAN, 102 00:03:31,440 --> 00:03:33,840 any untagged traffic coming into the trunk port 103 00:03:33,840 --> 00:03:36,750 is automatically going to be assigned to VLAN 10. 104 00:03:36,750 --> 00:03:38,610 This setup ensures seamless communication 105 00:03:38,610 --> 00:03:40,320 between our older legacy equipment 106 00:03:40,320 --> 00:03:41,790 that doesn't support VLANs 107 00:03:41,790 --> 00:03:44,580 and our newer more modern VLAN capable switches. 108 00:03:44,580 --> 00:03:46,590 This helps to maintain our network functionality 109 00:03:46,590 --> 00:03:48,600 without requiring us to do a complete overhaul 110 00:03:48,600 --> 00:03:51,210 of all of our existing network infrastructure. 111 00:03:51,210 --> 00:03:53,070 Now, for the native VLAN to work though, 112 00:03:53,070 --> 00:03:54,750 you have to ensure that the native VLAN 113 00:03:54,750 --> 00:03:56,010 is consistently configured 114 00:03:56,010 --> 00:03:58,170 across all of your interconnected switches 115 00:03:58,170 --> 00:04:00,840 to avoid misrouting your untagged traffic. 116 00:04:00,840 --> 00:04:04,770 By default, the native VLAN is usually defined as VLAN one, 117 00:04:04,770 --> 00:04:06,960 but most cybersecurity experts will recommend 118 00:04:06,960 --> 00:04:09,090 that you rename the native VLAN to something else 119 00:04:09,090 --> 00:04:11,610 like VLAN 10 or VLAN 100 120 00:04:11,610 --> 00:04:13,020 in order to prevent an attacker 121 00:04:13,020 --> 00:04:14,670 from successfully implementing what's known 122 00:04:14,670 --> 00:04:16,800 as a VLAN hopping attack. 123 00:04:16,800 --> 00:04:19,110 Third, we have a voice VLAN. 124 00:04:19,110 --> 00:04:21,269 Now, a voice VLAN is a specialized VLAN 125 00:04:21,269 --> 00:04:23,160 that's dedicated to your voice traffic, 126 00:04:23,160 --> 00:04:24,930 particularly voiceover IP 127 00:04:24,930 --> 00:04:27,210 or VoIP traffic within your network. 128 00:04:27,210 --> 00:04:29,220 The primary purpose of the voice VLAN 129 00:04:29,220 --> 00:04:30,360 is to ensure that the quality 130 00:04:30,360 --> 00:04:33,420 and reliability of your voice communications is insured 131 00:04:33,420 --> 00:04:34,890 by separating voice traffic out 132 00:04:34,890 --> 00:04:36,840 from your regular data traffic. 133 00:04:36,840 --> 00:04:38,550 This segregation by traffic type 134 00:04:38,550 --> 00:04:41,160 is essential because voice traffic is highly sensitive 135 00:04:41,160 --> 00:04:43,140 to delays and packet loss. 136 00:04:43,140 --> 00:04:45,270 By setting up a dedicated voice VLAN, 137 00:04:45,270 --> 00:04:46,470 we can configure our switches 138 00:04:46,470 --> 00:04:48,120 to prioritize the voice traffic 139 00:04:48,120 --> 00:04:50,340 by enabling the application of quality of service 140 00:04:50,340 --> 00:04:51,900 or QOS policies 141 00:04:51,900 --> 00:04:53,850 to optimize our voice communications 142 00:04:53,850 --> 00:04:56,250 and to ensure that we maintain higher levels of clarity 143 00:04:56,250 --> 00:04:58,710 and better continuity for our voice calls, 144 00:04:58,710 --> 00:05:01,350 even when our network is under heavy loads. 145 00:05:01,350 --> 00:05:03,390 For example, in a business environment 146 00:05:03,390 --> 00:05:06,510 where both data and VoIP services are used extensively, 147 00:05:06,510 --> 00:05:07,980 implementing a voice VLAN 148 00:05:07,980 --> 00:05:10,560 can significantly improve your call quality. 149 00:05:10,560 --> 00:05:12,720 When you set up a network device like your VoIP phones 150 00:05:12,720 --> 00:05:14,550 and your conference room video teleconference 151 00:05:14,550 --> 00:05:16,110 or VTC systems, 152 00:05:16,110 --> 00:05:17,190 you need to configure them 153 00:05:17,190 --> 00:05:19,650 to send their traffic through the voice VLAN. 154 00:05:19,650 --> 00:05:22,410 This way, whenever an employee places a VoIP call, 155 00:05:22,410 --> 00:05:23,790 the data packets from that call 156 00:05:23,790 --> 00:05:25,650 are going to be tagged for the voice VLAN, 157 00:05:25,650 --> 00:05:27,870 and this VLAN will have its traffic prioritized 158 00:05:27,870 --> 00:05:31,620 over other types of data traffic like email or web browsing. 159 00:05:31,620 --> 00:05:32,580 By doing this, 160 00:05:32,580 --> 00:05:34,020 you can ensure that the voice packets 161 00:05:34,020 --> 00:05:35,570 are given precedence in your network 162 00:05:35,570 --> 00:05:38,100 so that the latency, jitter, and packet losses 163 00:05:38,100 --> 00:05:39,810 are going to be reduced. 164 00:05:39,810 --> 00:05:42,180 Fourth, we have link aggregation. 165 00:05:42,180 --> 00:05:43,350 Now, link aggregation, 166 00:05:43,350 --> 00:05:45,600 also known as port channeling or bonding, 167 00:05:45,600 --> 00:05:46,890 is a method used in networks 168 00:05:46,890 --> 00:05:48,990 to combine multiple network connections together 169 00:05:48,990 --> 00:05:51,150 into a single logical link. 170 00:05:51,150 --> 00:05:52,890 This link aggregation technique 171 00:05:52,890 --> 00:05:54,510 enhances the bandwidth capacity 172 00:05:54,510 --> 00:05:55,860 and it provides redundancy 173 00:05:55,860 --> 00:05:58,200 for higher levels of network availability. 174 00:05:58,200 --> 00:05:59,550 By aggregating, bonding, 175 00:05:59,550 --> 00:06:01,980 or teaming our network lines together this way, 176 00:06:01,980 --> 00:06:03,960 we can combine multiple network links 177 00:06:03,960 --> 00:06:06,240 so that our data can be distributed across multiple links 178 00:06:06,240 --> 00:06:07,560 in an organized manner 179 00:06:07,560 --> 00:06:08,940 to utilize the combined bandwidth 180 00:06:08,940 --> 00:06:10,980 of all of those combined links. 181 00:06:10,980 --> 00:06:11,813 Now, additionally, 182 00:06:11,813 --> 00:06:12,960 link aggregation will help 183 00:06:12,960 --> 00:06:15,060 to provide redundancy and resiliency 184 00:06:15,060 --> 00:06:16,920 because our network traffic can continue to flow 185 00:06:16,920 --> 00:06:18,090 over the remaining links 186 00:06:18,090 --> 00:06:20,340 to minimize the risk of a complete network outage 187 00:06:20,340 --> 00:06:22,620 if one of your links in the aggregated links 188 00:06:22,620 --> 00:06:24,180 happens to fail. 189 00:06:24,180 --> 00:06:26,070 Now, link aggregation is commonly used 190 00:06:26,070 --> 00:06:28,830 to support trunking lines between our switches as well. 191 00:06:28,830 --> 00:06:32,700 After all, if I have a 24 port one gigabit per second switch 192 00:06:32,700 --> 00:06:35,370 and we're only using one gigabit per second network uplinks 193 00:06:35,370 --> 00:06:36,840 between each of our switches, 194 00:06:36,840 --> 00:06:38,490 this will cause a bottleneck in our network 195 00:06:38,490 --> 00:06:41,730 because these trunk lines can quickly become overloaded. 196 00:06:41,730 --> 00:06:44,010 Instead, if you have a 24 port switch 197 00:06:44,010 --> 00:06:46,410 with one gigabit per second switch ports on it, 198 00:06:46,410 --> 00:06:47,280 I recommend that you use 199 00:06:47,280 --> 00:06:49,200 either a 10 gigabit per second fiber link 200 00:06:49,200 --> 00:06:50,460 between your switches, 201 00:06:50,460 --> 00:06:53,700 or you use link aggregation across four switchboards 202 00:06:53,700 --> 00:06:55,290 to provide at least an aggregated 203 00:06:55,290 --> 00:06:58,110 four gigabits per second network link between your switches 204 00:06:58,110 --> 00:07:00,150 for your VLAN trunks to use. 205 00:07:00,150 --> 00:07:02,460 For example, if you're working in a data center 206 00:07:02,460 --> 00:07:04,200 where consistent high speed connectivity 207 00:07:04,200 --> 00:07:06,180 is crucial for your server operations, 208 00:07:06,180 --> 00:07:08,490 you probably want to configure the use of link aggregation 209 00:07:08,490 --> 00:07:10,050 with all of your switches. 210 00:07:10,050 --> 00:07:11,820 By implementing link aggregation, 211 00:07:11,820 --> 00:07:13,350 your server can be connected to a switch 212 00:07:13,350 --> 00:07:15,120 via multiple ethernet cables 213 00:07:15,120 --> 00:07:17,100 to effectively multiply the available bandwidth 214 00:07:17,100 --> 00:07:18,420 to that server. 215 00:07:18,420 --> 00:07:19,890 So if we're able to aggregate 216 00:07:19,890 --> 00:07:22,080 four one gigabit per second links together, 217 00:07:22,080 --> 00:07:23,820 we're actually creating a total bandwidth 218 00:07:23,820 --> 00:07:26,490 of four gigabits per second for us to use. 219 00:07:26,490 --> 00:07:28,470 This aggregation not only provides 220 00:07:28,470 --> 00:07:29,700 a high throughput connection 221 00:07:29,700 --> 00:07:31,860 that's suitable for intensive data operations, 222 00:07:31,860 --> 00:07:33,660 but also ensures network resilience 223 00:07:33,660 --> 00:07:35,760 because our server can maintain its network connection 224 00:07:35,760 --> 00:07:36,690 to its remaining links 225 00:07:36,690 --> 00:07:39,360 if one of those four links happens to fail. 226 00:07:39,360 --> 00:07:40,410 This type of redundancy 227 00:07:40,410 --> 00:07:42,150 is particularly critical in environments 228 00:07:42,150 --> 00:07:44,178 where downtime will have a significant operational 229 00:07:44,178 --> 00:07:47,190 or financial implications on your business. 230 00:07:47,190 --> 00:07:50,400 Fifth, we have speed and duplex configurations. 231 00:07:50,400 --> 00:07:52,890 Now, speed and duplex configurations in a network 232 00:07:52,890 --> 00:07:54,300 are the settings that are used to determine 233 00:07:54,300 --> 00:07:56,310 the rate at which data is going to be transmitted 234 00:07:56,310 --> 00:07:59,760 and the mode of communication between your network devices. 235 00:07:59,760 --> 00:08:01,110 Now, when we talk about speed, 236 00:08:01,110 --> 00:08:03,180 we're referring to the rate of data transfer, 237 00:08:03,180 --> 00:08:04,500 and this is typically going to be measured 238 00:08:04,500 --> 00:08:07,440 in megabits per second or gigabits per second. 239 00:08:07,440 --> 00:08:09,030 Now, duplex, on the other hand, 240 00:08:09,030 --> 00:08:11,910 refers to how data is going to be sent over that connection, 241 00:08:11,910 --> 00:08:14,940 and this can either be half duplex or full duplex. 242 00:08:14,940 --> 00:08:16,410 In half duplex mode, 243 00:08:16,410 --> 00:08:19,620 data transmission and reception cannot occur simultaneously, 244 00:08:19,620 --> 00:08:22,860 and instead, your device can either send or receive data, 245 00:08:22,860 --> 00:08:25,530 but it can't do both at any given time. 246 00:08:25,530 --> 00:08:27,060 Now, this works like walkie-talkies 247 00:08:27,060 --> 00:08:29,070 that you may have used back when you were a kid. 248 00:08:29,070 --> 00:08:30,120 If you were talking, 249 00:08:30,120 --> 00:08:32,280 your friend on the other end had to listen. 250 00:08:32,280 --> 00:08:33,990 Then when they wanted to talk, 251 00:08:33,990 --> 00:08:37,320 you had to stop and listen before you could transmit again. 252 00:08:37,320 --> 00:08:39,330 Now in full duplex mode, on the other hand, 253 00:08:39,330 --> 00:08:40,289 this allows for a device 254 00:08:40,289 --> 00:08:42,720 to send and receive data simultaneously. 255 00:08:42,720 --> 00:08:43,890 Full duplex mode 256 00:08:43,890 --> 00:08:46,050 will help to increase our overall transfer speed 257 00:08:46,050 --> 00:08:48,240 because it effectively doubles our network capacity 258 00:08:48,240 --> 00:08:50,580 when compared to half duplex mode. 259 00:08:50,580 --> 00:08:52,350 Now, speed and duplex configurations 260 00:08:52,350 --> 00:08:53,910 are something that network administrators 261 00:08:53,910 --> 00:08:55,140 will often overlook, 262 00:08:55,140 --> 00:08:56,940 and it can really slow down your network's performance 263 00:08:56,940 --> 00:08:59,160 if you don't ensure it's properly configured. 264 00:08:59,160 --> 00:09:00,540 For example, let's assume 265 00:09:00,540 --> 00:09:02,040 that you have a high performance server 266 00:09:02,040 --> 00:09:04,290 that's connected to one of your network switches. 267 00:09:04,290 --> 00:09:05,490 If that server is capable 268 00:09:05,490 --> 00:09:08,670 of handling a one gigabit per second full duplex connection, 269 00:09:08,670 --> 00:09:10,530 but the device was incorrectly configured 270 00:09:10,530 --> 00:09:12,300 to operate at 100 megabits per second, 271 00:09:12,300 --> 00:09:14,460 using a half duplex mode connection, 272 00:09:14,460 --> 00:09:16,740 this misconfiguration will significantly limit 273 00:09:16,740 --> 00:09:17,760 your data throughput 274 00:09:17,760 --> 00:09:19,950 to one 10th of the service capacity 275 00:09:19,950 --> 00:09:21,750 because it's configured to send and receive data 276 00:09:21,750 --> 00:09:23,550 at only a hundred megabits per second 277 00:09:23,550 --> 00:09:25,170 of that one gigabit per second 278 00:09:25,170 --> 00:09:26,310 that the server could support 279 00:09:26,310 --> 00:09:28,380 at its maximum transmission speed. 280 00:09:28,380 --> 00:09:31,590 Additionally, if that device is configured for half duplex, 281 00:09:31,590 --> 00:09:33,720 even though it could support full duplex, 282 00:09:33,720 --> 00:09:36,150 this misconfiguration will restrict our communication 283 00:09:36,150 --> 00:09:38,070 to one way at a given time, 284 00:09:38,070 --> 00:09:39,900 and this will lead to more network congestion 285 00:09:39,900 --> 00:09:41,220 and performance issues 286 00:09:41,220 --> 00:09:43,530 that could effectively half the amount of speed 287 00:09:43,530 --> 00:09:45,210 that we're going to see out our networks. 288 00:09:45,210 --> 00:09:46,850 So by correcting the misconfiguration 289 00:09:46,850 --> 00:09:48,870 of the server speed and duplex settings 290 00:09:48,870 --> 00:09:50,850 to match its maximum capabilities, 291 00:09:50,850 --> 00:09:51,810 we're going to be able to ensure 292 00:09:51,810 --> 00:09:53,580 that we're receiving optimal network performance 293 00:09:53,580 --> 00:09:55,320 for all of our devices. 294 00:09:55,320 --> 00:09:57,840 Now, most devices are going to be configured out of the box 295 00:09:57,840 --> 00:10:00,360 to support what's known as auto-negotiation. 296 00:10:00,360 --> 00:10:02,250 Auto-negotiation is commonly used 297 00:10:02,250 --> 00:10:03,510 when devices automatically select 298 00:10:03,510 --> 00:10:06,120 the highest performance settings that they have in common. 299 00:10:06,120 --> 00:10:08,130 However, in certain situations 300 00:10:08,130 --> 00:10:09,810 such as when you're using legacy equipment 301 00:10:09,810 --> 00:10:11,910 or specific performance requirements, 302 00:10:11,910 --> 00:10:14,400 you may want to use manual configurations instead 303 00:10:14,400 --> 00:10:16,590 to be able to achieve the desired network efficiency 304 00:10:16,590 --> 00:10:19,860 because auto-negotiation can sometimes lead to lower speeds 305 00:10:19,860 --> 00:10:22,080 and wrong duplex settings being negotiated 306 00:10:22,080 --> 00:10:24,000 because the devices aren't being configured 307 00:10:24,000 --> 00:10:26,460 for their maximum settings like they should be. 308 00:10:26,460 --> 00:10:28,950 So remember, configuring VLAN is a critical skill 309 00:10:28,950 --> 00:10:30,450 for network professionals. 310 00:10:30,450 --> 00:10:33,300 You have to understand 802.1Q tagging, 311 00:10:33,300 --> 00:10:34,380 the native VLAN, 312 00:10:34,380 --> 00:10:36,450 a voice VLAN, link aggregation, 313 00:10:36,450 --> 00:10:38,670 and speed and duplex configurations 314 00:10:38,670 --> 00:10:40,050 if you want to be able to design 315 00:10:40,050 --> 00:10:43,260 and manage efficient, secure, and robust networks. 316 00:10:43,260 --> 00:10:45,690 802.1Q tagging is a network standard 317 00:10:45,690 --> 00:10:48,360 that adds a VLAN ID to ethernet frames 318 00:10:48,360 --> 00:10:50,340 to help efficiently manage and route data 319 00:10:50,340 --> 00:10:53,820 across multiple virtual local area networks or VLANs 320 00:10:53,820 --> 00:10:55,710 on your same physical network. 321 00:10:55,710 --> 00:10:58,980 The native VLAN is going to be the default VLAN on a trunk port 322 00:10:58,980 --> 00:11:00,960 that carries all of your untag traffic 323 00:11:00,960 --> 00:11:02,580 to ensure compatibility with devices 324 00:11:02,580 --> 00:11:04,560 that do not support VLAN tagging 325 00:11:04,560 --> 00:11:06,930 such as older legacy devices. 326 00:11:06,930 --> 00:11:10,260 A voice VLAN is a dedicated VLAN on a network switch 327 00:11:10,260 --> 00:11:11,580 that's configured to prioritize 328 00:11:11,580 --> 00:11:13,950 and segregate voiceover IP traffic 329 00:11:13,950 --> 00:11:15,870 to ensure its quality and reliability 330 00:11:15,870 --> 00:11:17,790 of those voice communications. 331 00:11:17,790 --> 00:11:19,530 Link aggregation is going to combine 332 00:11:19,530 --> 00:11:21,240 multiple physical network connections 333 00:11:21,240 --> 00:11:23,130 into a single logical connection 334 00:11:23,130 --> 00:11:24,360 that will increase the bandwidth 335 00:11:24,360 --> 00:11:26,310 and provide redundancy for us. 336 00:11:26,310 --> 00:11:28,680 And then we have speed and duplex configurations, 337 00:11:28,680 --> 00:11:29,760 which are going to be used to determine 338 00:11:29,760 --> 00:11:31,200 the rate of data transmission 339 00:11:31,200 --> 00:11:33,930 in either megabits per second or gigabits per second, 340 00:11:33,930 --> 00:11:35,220 and the mode of communication 341 00:11:35,220 --> 00:11:37,470 that is going to be used between the network devices 342 00:11:37,470 --> 00:11:38,460 like full duplex 343 00:11:38,460 --> 00:11:40,770 for simultaneous sending and receiving of your data 344 00:11:40,770 --> 00:11:43,350 or half duplex for devices that will alternate 345 00:11:43,350 --> 00:11:46,233 between sending and receiving data at any given time.