1 00:00:00,020 --> 00:00:01,020 In this lesson, 2 00:00:01,020 --> 00:00:02,400 we're going to explore the concept 3 00:00:02,400 --> 00:00:05,550 of a virtual extensible local area network. 4 00:00:05,550 --> 00:00:08,039 Now, a virtual extensible local area network, 5 00:00:08,039 --> 00:00:09,960 also known as a VXLAN, 6 00:00:09,960 --> 00:00:12,060 is a network virtualization technology 7 00:00:12,060 --> 00:00:13,560 that addresses the limitations posed 8 00:00:13,560 --> 00:00:15,780 by traditional network infrastructures. 9 00:00:15,780 --> 00:00:18,690 As enterprises and data centers continue to expand, 10 00:00:18,690 --> 00:00:20,580 the need for more scalable, flexible, 11 00:00:20,580 --> 00:00:24,090 and efficient virtual networks has become a critical need. 12 00:00:24,090 --> 00:00:26,790 VXLAN technology plays a pivotal role in catering 13 00:00:26,790 --> 00:00:29,760 to these demands by facilitating the creation of a larger 14 00:00:29,760 --> 00:00:31,530 and more agile network. 15 00:00:31,530 --> 00:00:34,230 VXLAN is a network overlay technology 16 00:00:34,230 --> 00:00:36,060 that's designed to encapsulate ethernet frames 17 00:00:36,060 --> 00:00:37,920 within a UDP packet. 18 00:00:37,920 --> 00:00:40,290 VXLAN extends the Layer 2 network 19 00:00:40,290 --> 00:00:42,060 over a Layer 3 infrastructure 20 00:00:42,060 --> 00:00:44,010 to create a virtualized Layer 2 network 21 00:00:44,010 --> 00:00:46,770 that can span physical Layer 3 networks as well. 22 00:00:46,770 --> 00:00:49,110 This technique enables the deployment of a large number 23 00:00:49,110 --> 00:00:51,780 of virtual networks with isolated address spaces 24 00:00:51,780 --> 00:00:54,600 across a shared physical network infrastructure. 25 00:00:54,600 --> 00:00:55,620 Now, the primary driver 26 00:00:55,620 --> 00:00:57,870 behind VXLAN's inception was the need 27 00:00:57,870 --> 00:01:01,170 to overcome the scalability limitations of traditional VLANs 28 00:01:01,170 --> 00:01:03,270 or virtual local area networks. 29 00:01:03,270 --> 00:01:06,480 VLANs are restricted to a 12 bit VLAN identifier, 30 00:01:06,480 --> 00:01:10,170 so your networks could only have 4,096 unique VLANs, 31 00:01:10,170 --> 00:01:11,700 which may sound like a lot, 32 00:01:11,700 --> 00:01:14,820 but this limitation is really insufficient for our modern, 33 00:01:14,820 --> 00:01:16,470 vast segmented networks 34 00:01:16,470 --> 00:01:17,730 that are used in our large scale 35 00:01:17,730 --> 00:01:20,070 cloud computing environments these days. 36 00:01:20,070 --> 00:01:22,740 So how does a VXLAN work? 37 00:01:22,740 --> 00:01:24,360 Well, VXLANs operate 38 00:01:24,360 --> 00:01:26,550 by encapsulating Layer 2 ethernet frames 39 00:01:26,550 --> 00:01:29,010 within Layer 4 UDP packets. 40 00:01:29,010 --> 00:01:31,440 This encapsulation process allows for the creation 41 00:01:31,440 --> 00:01:33,570 of a tunnel across a Layer 3 network, 42 00:01:33,570 --> 00:01:36,750 which can be a WAN, a LAN, or even the internet. 43 00:01:36,750 --> 00:01:38,580 Each VXLAN packet includes 44 00:01:38,580 --> 00:01:43,140 a 24 bit VXLAN network identifier known as a VNI 45 00:01:43,140 --> 00:01:44,790 and this significantly expands the number 46 00:01:44,790 --> 00:01:47,760 of available identifiers from 4,096 47 00:01:47,760 --> 00:01:50,640 all the way up to over 16 million identifiers 48 00:01:50,640 --> 00:01:52,050 to address the scalability issues 49 00:01:52,050 --> 00:01:54,300 that we have with traditional VLANs. 50 00:01:54,300 --> 00:01:56,580 Now, when using a VXLAN setup, 51 00:01:56,580 --> 00:01:59,460 you're going to find two primary components are going to be used. 52 00:01:59,460 --> 00:02:03,480 These are the VXLAN tunnel endpoints and the VXLAN segments. 53 00:02:03,480 --> 00:02:07,890 First, we have VXLAN tunnel endpoints known as VTEPs. 54 00:02:07,890 --> 00:02:10,229 These VXLAN tunnel endpoints are entities 55 00:02:10,229 --> 00:02:12,630 that perform the encapsulation and de encapsulation 56 00:02:12,630 --> 00:02:16,140 of the ethernet frames into those VXLAN packets. 57 00:02:16,140 --> 00:02:18,780 VTEPs are typically implemented within hypervisors 58 00:02:18,780 --> 00:02:20,040 that host the virtual machines 59 00:02:20,040 --> 00:02:22,530 or within your physical network switches. 60 00:02:22,530 --> 00:02:25,140 Second, we have the VXLAN segment. 61 00:02:25,140 --> 00:02:28,050 The VXLAN segment is a Layer 2 network overlaid 62 00:02:28,050 --> 00:02:31,050 onto a Layer 3 network that is then identified using 63 00:02:31,050 --> 00:02:36,050 that unique 24 bit VXLAN network identifier, or VNI. 64 00:02:36,060 --> 00:02:38,640 Virtual machines within the same VXLAN segment 65 00:02:38,640 --> 00:02:39,900 can communicate with each other 66 00:02:39,900 --> 00:02:42,420 as if they were on the same physical Layer 2 network, 67 00:02:42,420 --> 00:02:45,090 regardless of their actual physical location. 68 00:02:45,090 --> 00:02:46,470 Now, VXLANs offer us 69 00:02:46,470 --> 00:02:49,620 with numerous benefits including scalability, flexibility, 70 00:02:49,620 --> 00:02:51,420 and improved utilization. 71 00:02:51,420 --> 00:02:53,520 First, we have scalability. 72 00:02:53,520 --> 00:02:56,820 Now with a 24 bit VNI, VXLAN can support up 73 00:02:56,820 --> 00:02:58,770 to 16 million virtual networks, 74 00:02:58,770 --> 00:03:00,870 which our organizations to scale their networks 75 00:03:00,870 --> 00:03:02,730 as needed without being constrained 76 00:03:02,730 --> 00:03:06,990 by the previous VLAN ID limits of 4,096. 77 00:03:06,990 --> 00:03:09,030 Second, we have flexibility. 78 00:03:09,030 --> 00:03:11,520 Since VXLANs traverse Layer 3 networks 79 00:03:11,520 --> 00:03:12,900 and they don't require any changes 80 00:03:12,900 --> 00:03:14,280 to the underlying network, 81 00:03:14,280 --> 00:03:16,860 this makes it possible to extend our Layer 2 networks 82 00:03:16,860 --> 00:03:20,160 across different data centers or cloud environments as well. 83 00:03:20,160 --> 00:03:22,590 Third, we have improved utilization. 84 00:03:22,590 --> 00:03:25,530 VXLAN allows for more efficient use of the network paths 85 00:03:25,530 --> 00:03:28,410 and bandwidth by optimizing our traffic flows within 86 00:03:28,410 --> 00:03:30,330 and across our data centers. 87 00:03:30,330 --> 00:03:34,050 So how might VXLANs be used in the real world? 88 00:03:34,050 --> 00:03:36,240 Well, in a typical data center environment, 89 00:03:36,240 --> 00:03:38,220 virtual machines across different servers 90 00:03:38,220 --> 00:03:39,810 need to communicate with each other. 91 00:03:39,810 --> 00:03:42,330 If these servers are spread across multiple locations, 92 00:03:42,330 --> 00:03:44,220 traditional VLANs may not suffice 93 00:03:44,220 --> 00:03:46,680 due to their scalability limitations 94 00:03:46,680 --> 00:03:48,600 and this is where VXLAN steps in 95 00:03:48,600 --> 00:03:49,650 because it can encapsulate 96 00:03:49,650 --> 00:03:51,450 that traffic from these virtual machines 97 00:03:51,450 --> 00:03:53,850 within the UDP packets and allow for the data 98 00:03:53,850 --> 00:03:56,910 to traverse any IP network while maintaining the illusion 99 00:03:56,910 --> 00:03:59,100 of being a single Layer 2 network. 100 00:03:59,100 --> 00:04:01,470 This is especially beneficial for applications 101 00:04:01,470 --> 00:04:03,600 that require a consistent network topology 102 00:04:03,600 --> 00:04:06,240 regardless of the underlying physical network. 103 00:04:06,240 --> 00:04:08,130 Now, even though VXLANs can provide us 104 00:04:08,130 --> 00:04:10,650 with a robust solution for network virtualization, 105 00:04:10,650 --> 00:04:12,150 there are challenges and considerations 106 00:04:12,150 --> 00:04:15,090 that you need to keep in mind when using VXLANs. 107 00:04:15,090 --> 00:04:17,399 VXLANs can be complex to configure. 108 00:04:17,399 --> 00:04:18,930 When you're implementing a VXLAN, 109 00:04:18,930 --> 00:04:21,149 you have to have a good understanding of both Layer 2 110 00:04:21,149 --> 00:04:23,790 and Layer 3 networking, as well as the intricacies 111 00:04:23,790 --> 00:04:25,440 of network overlays. 112 00:04:25,440 --> 00:04:27,030 Also, the encapsulation 113 00:04:27,030 --> 00:04:29,700 and de encapsulation process can introduce latency 114 00:04:29,700 --> 00:04:32,400 and increase the packet size due to the encapsulation 115 00:04:32,400 --> 00:04:33,930 and this can result in higher overhead 116 00:04:33,930 --> 00:04:35,460 inside of your networks. 117 00:04:35,460 --> 00:04:38,280 Finally, VXLANs do require multicast support 118 00:04:38,280 --> 00:04:39,780 within the underlying network, 119 00:04:39,780 --> 00:04:41,430 so you can use that for broadcasting 120 00:04:41,430 --> 00:04:43,260 and unknown unicast traffic 121 00:04:43,260 --> 00:04:44,940 and this can be a challenge in some corporate 122 00:04:44,940 --> 00:04:47,610 or enterprise environments depending on your configuration 123 00:04:47,610 --> 00:04:49,770 and your current security posture. 124 00:04:49,770 --> 00:04:51,270 Now despite these challenges, 125 00:04:51,270 --> 00:04:52,590 the deployment of VXLANs 126 00:04:52,590 --> 00:04:54,270 can be significantly simplified 127 00:04:54,270 --> 00:04:56,790 with the use of management and orchestration tools 128 00:04:56,790 --> 00:04:58,050 that automate the configuration 129 00:04:58,050 --> 00:05:00,870 and management of your VXLAN networks on your behalf, 130 00:05:00,870 --> 00:05:03,630 especially when you're operating in a cloud-based network. 131 00:05:03,630 --> 00:05:06,960 So remember, a VXLAN represents a significant advancement 132 00:05:06,960 --> 00:05:09,360 in network virtualization by providing the means 133 00:05:09,360 --> 00:05:11,190 to create extensible, scalable, 134 00:05:11,190 --> 00:05:12,810 and efficient virtual networks 135 00:05:12,810 --> 00:05:15,000 over existing network architectures. 136 00:05:15,000 --> 00:05:17,640 VXLAN is a network overlay technology 137 00:05:17,640 --> 00:05:19,410 that's designed to encapsulate ethernet frames 138 00:05:19,410 --> 00:05:21,090 within a UDP packet. 139 00:05:21,090 --> 00:05:23,280 VXLAN will extend the Layer 2 network 140 00:05:23,280 --> 00:05:24,990 over a Layer 3 infrastructure 141 00:05:24,990 --> 00:05:26,910 to create a virtualized Layer 2 network 142 00:05:26,910 --> 00:05:30,270 that can span physical Layer 3 networks across the globe. 143 00:05:30,270 --> 00:05:33,030 Understanding VXLAN is going to be an essential thing for you 144 00:05:33,030 --> 00:05:35,220 as a network professional if you aim to design 145 00:05:35,220 --> 00:05:36,840 and manage advanced, scalable, 146 00:05:36,840 --> 00:05:38,340 and flexible network solutions 147 00:05:38,340 --> 00:05:40,143 in our modern distributed networks.