1 00:00:00,001-->00:00:03,000 What guidance does Cisco give us on the data center 2 00:00:03,001-->00:00:05,000 architecture that they would recommend? 3 00:00:05,001-->00:00:09,000 What exam questions might we expect on this topic? 4 00:00:09,001-->00:00:13,000 Let's answer those questions and more in this Nugget. 5 00:00:13,001-->00:00:15,000 We really want to focus this Nugget into three 6 00:00:15,001-->00:00:16,000 areas, by the way. 7 00:00:16,001-->00:00:20,000 We want to talk about why it is that we see Local Area 8 00:00:20,001-->00:00:23,000 Networks and Storage Area Networks segregated. 9 00:00:23,001-->00:00:27,000 I mean, why wasn't always the desire of organizations to 10 00:00:27,001-->00:00:30,000 take this traffic and mesh it together. 11 00:00:30,001-->00:00:31,000 We'll see why in this Nugget. 12 00:00:31,001-->00:00:35,000 We'll also talk about the three layered architecture 13 00:00:35,001-->00:00:38,000 that Cisco likes to recommend for network infrastructures. 14 00:00:38,001-->00:00:40,000 And we'll talk about a variation of it called the 15 00:00:40,001-->00:00:42,000 collapsed core. 16 00:00:42,001-->00:00:45,000 And then finally, we'll wrap up just by giving you some 17 00:00:45,001-->00:00:49,000 overview information of the most important categories of 18 00:00:49,001-->00:00:52,000 what Cisco calls this new evolution of their data center 19 00:00:52,001-->00:00:53,000 networking. 20 00:00:53,001-->00:00:55,000 They call it 3.0. 21 00:00:55,001-->00:00:57,000 I know I've taught it to you in other courses. 22 00:00:57,001-->00:01:00,000 But in this particular course, let's make sure that we 23 00:01:00,001-->00:01:05,000 understand the major tenants of Data Center 3.0. 24 00:01:05,001-->00:01:09,000 So why is that we so often see the Local Area Network 25 00:01:09,001-->00:01:12,000 completely segregated from the Storage Area Network? 26 00:01:12,001-->00:01:16,000 There's a real attempt to keep the Local Area Network traffic 27 00:01:16,001-->00:01:19,000 and the Storage Area Network traffic separate. 28 00:01:19,001-->00:01:21,000 Well one of the important reasons 29 00:01:21,001-->00:01:23,000 has always been security. 30 00:01:23,001-->00:01:27,000 The idea is that hacking methodologies that would work 31 00:01:27,001-->00:01:28,000 in the Local Area Network. 32 00:01:28,001-->00:01:33,000 If we segregate the storage stuff off of that LAN, those 33 00:01:33,001-->00:01:36,000 same hacking methodologies would not work. 34 00:01:36,001-->00:01:40,000 Another real big reason was always bandwidth. 35 00:01:40,001-->00:01:44,000 The Local Area Network was perceived to be a much lower 36 00:01:44,001-->00:01:48,000 bandwidth infrastructure then the Storage Area Network. 37 00:01:48,001-->00:01:52,000 So we'd take our data, put it in the SAN, and give it 38 00:01:52,001-->00:01:55,000 really, really high bandwidth amounts. 39 00:01:55,001-->00:01:58,000 Now we know today the Local Area Network is certainly 40 00:01:58,001-->00:02:01,000 catching up with the bandwidth capabilities of the SAN. 41 00:02:01,001-->00:02:03,000 And that's definitely a consideration. 42 00:02:03,001-->00:02:07,000 Another major factor for the segregation has always been 43 00:02:07,001-->00:02:08,000 flow control. 44 00:02:08,001-->00:02:12,000 Let me elaborate on flow control next in this 45 00:02:12,001-->00:02:13,000 particular Nugget. 46 00:02:13,001-->00:02:18,000 But just suffice it to say that in TCP/IP based LAN 47 00:02:18,001-->00:02:21,000 environments, there can be a lot of bottlenecks. 48 00:02:21,001-->00:02:25,000 And these bottlenecks can lead to dropped packets. 49 00:02:25,001-->00:02:28,000 Dropped packets is something that is not tolerated in the 50 00:02:28,001-->00:02:30,000 Storage Area Networking environment. 51 00:02:30,001-->00:02:33,000 And finally, overall performance. 52 00:02:33,001-->00:02:37,000 It was deemed that the Storage Area Network segregated 53 00:02:37,001-->00:02:41,000 information would achieve higher performance levels than 54 00:02:41,001-->00:02:44,000 that all of the Local Area network. 55 00:02:44,001-->00:02:47,000 Now something else to keep in mind-- as I alluded to-- is 56 00:02:47,001-->00:02:50,000 Storage Area Networks just don't really appreciate the 57 00:02:50,001-->00:02:53,000 way in which LANs do their flow control. 58 00:02:53,001-->00:02:55,000 Remember what happens. 59 00:02:55,001-->00:02:59,000 In a LAN environment, a transmitter will be firing 60 00:02:59,001-->00:03:01,000 packets off at the receiver. 61 00:03:01,001-->00:03:04,000 If the receiver gets congested, it 62 00:03:04,001-->00:03:06,000 will drop some packets. 63 00:03:06,001-->00:03:10,000 And it will try and signaled to the transmitter that it is 64 00:03:10,001-->00:03:12,000 experiencing congestion. 65 00:03:12,001-->00:03:16,000 At that point, the transmitter can slow down-- can reduce the 66 00:03:16,001-->00:03:19,000 number of packets that it is sending in a 67 00:03:19,001-->00:03:20,000 specific time interval. 68 00:03:20,001-->00:03:26,000 This lost packets problem with the flow control mechanisms of 69 00:03:26,001-->00:03:29,000 ethernet is something that Storage Area Networks just 70 00:03:29,001-->00:03:31,000 cannot tolerate. 71 00:03:31,001-->00:03:34,000 So what happens in the Storage Area Network environment 72 00:03:34,001-->00:03:35,000 that's so different? 73 00:03:35,001-->00:03:38,000 Well the protocol over there is called fibre channel. 74 00:03:38,001-->00:03:40,000 And what it's going to do is it's going to have the 75 00:03:40,001-->00:03:44,000 receiver really control the situation, instead of the 76 00:03:44,001-->00:03:45,000 transmitter. 77 00:03:45,001-->00:03:48,000 Specifically, it's a credit based system. 78 00:03:48,001-->00:03:50,000 So the receiver will say, OK, go for it. 79 00:03:50,001-->00:03:52,000 The transmitter will then transmit. 80 00:03:52,001-->00:03:56,000 The receiver will say, OK, you can send x amount. 81 00:03:56,001-->00:03:59,000 The transmitter will say, OK, there is your x amount. 82 00:03:59,001-->00:04:03,000 So the transmitter will not send information unless it has 83 00:04:03,001-->00:04:08,000 credits that it receives from that particular receiver. 84 00:04:08,001-->00:04:11,000 This results in what appears to be inefficient 85 00:04:11,001-->00:04:12,000 communications. 86 00:04:12,001-->00:04:16,000 But that is traded off for the fact that we are absolutely 87 00:04:16,001-->00:04:19,000 not losing packets of data. 88 00:04:19,001-->00:04:21,000 Now as I'll talk about in a moment-- 89 00:04:21,001-->00:04:24,000 and as we'll elaborate on in future 90 00:04:24,001-->00:04:26,000 Nuggets of this course-- 91 00:04:26,001-->00:04:29,000 one of the cool technologies that we can do is unification 92 00:04:29,001-->00:04:31,000 of the LAN and SAN traffic. 93 00:04:31,001-->00:04:35,000 And you're probably aware that we're going to use the gigabit 94 00:04:35,001-->00:04:39,000 per second Ethernet of the Local Area Network, 95 00:04:39,001-->00:04:42,000 specifically the 10 gigabit per second. 96 00:04:42,001-->00:04:45,000 And we're going to take the fibre channel of the SAN, and 97 00:04:45,001-->00:04:48,000 we are going to be able to transmit them in the same 98 00:04:48,001-->00:04:49,000 environment. 99 00:04:49,001-->00:04:50,000 How do we do this? 100 00:04:50,001-->00:04:54,000 Well of course, it's fibre channel over Ethernet. 101 00:04:54,001-->00:04:56,000 We're going to take that fibre channel traffic, and we're 102 00:04:56,001-->00:04:59,000 going to insert it inside of a 10 gigabit per 103 00:04:59,001-->00:05:01,000 second Ethernet frame. 104 00:05:01,001-->00:05:03,000 Once again, this unified traffic-- 105 00:05:03,001-->00:05:06,000 this fibre channel over Ethernet technology-- 106 00:05:06,001-->00:05:08,000 is something that we'll elaborate on 107 00:05:08,001-->00:05:11,000 later in this course. 108 00:05:11,001-->00:05:14,000 Now keep in mind, when Cisco is designing these modern data 109 00:05:14,001-->00:05:19,000 center infrastructures, they will still use a layered and 110 00:05:19,001-->00:05:21,000 modular approach. 111 00:05:21,001-->00:05:25,000 This really helps the scalability of the design. 112 00:05:25,001-->00:05:29,000 It is very easy to go ahead and scale it out. 113 00:05:29,001-->00:05:34,000 And it's also very resilient, so this is a reliable 114 00:05:34,001-->00:05:37,000 resilient type of design. 115 00:05:37,001-->00:05:41,000 The layered approach says that we're going to have particular 116 00:05:41,001-->00:05:45,000 equipment that we consider the data center access layer. 117 00:05:45,001-->00:05:47,000 As you can see here in my depiction, this might be 118 00:05:47,001-->00:05:50,000 C-series rack mounted servers. 119 00:05:50,001-->00:05:53,000 These might be those B-series blade 120 00:05:53,001-->00:05:55,000 servers in a UCS chassis. 121 00:05:55,001-->00:05:59,000 We then have what's called an aggregation layer. 122 00:05:59,001-->00:06:03,000 And then finally, there is a high speed core layer. 123 00:06:03,001-->00:06:06,000 So if you're familiar with other design classes-- 124 00:06:06,001-->00:06:11,000 maybe even the CCDA training that we deliver here at CBT 125 00:06:11,001-->00:06:15,000 Nuggets, if you're familiar with this three layer concept 126 00:06:15,001-->00:06:17,000 of core aggregation and access-- 127 00:06:17,001-->00:06:20,000 you're going to feel really comfortable with the modular 128 00:06:20,001-->00:06:22,000 approach that's used in the data center. 129 00:06:22,001-->00:06:25,000 Because these three layers exist here as well. 130 00:06:25,001-->00:06:28,000 Now what you can run into in the Storage Area Network a lot 131 00:06:28,001-->00:06:33,000 of times is a small number of switches that have just a 132 00:06:33,001-->00:06:35,000 single layer. 133 00:06:35,001-->00:06:39,000 And these single layer of switches will make redundant 134 00:06:39,001-->00:06:42,000 connections to the servers that are actually providing 135 00:06:42,001-->00:06:43,000 your storage. 136 00:06:43,001-->00:06:46,000 Notice this is a pretty inexpensive and easy way to 137 00:06:46,001-->00:06:49,000 manage your environment, because you have a few number 138 00:06:49,001-->00:06:53,000 of switches to handle that have redundant connections out 139 00:06:53,001-->00:06:56,000 to the storage devices themselves. 140 00:06:56,001-->00:06:59,000 But as you might guess, this is not the only particular 141 00:06:59,001-->00:07:01,000 your architecture that is utilized. 142 00:07:01,001-->00:07:06,000 A lot of organizations will indeed start to scale this out 143 00:07:06,001-->00:07:09,000 by adding additional layers of storage switches. 144 00:07:09,001-->00:07:12,000 And we'll be talking about these types of designs and 145 00:07:12,001-->00:07:15,000 even how they are implemented in the course. 146 00:07:15,001-->00:07:18,000 One of the things that we're going to have obviously here 147 00:07:18,001-->00:07:22,000 is larger numbers of inter switch links connections in 148 00:07:22,001-->00:07:25,000 this particular Storage Area Networking environment. 149 00:07:25,001-->00:07:30,000 Now let us talk about these particular modular designs in 150 00:07:30,001-->00:07:31,000 more detail. 151 00:07:31,001-->00:07:34,000 For example, when we talk about the core layer of, let's 152 00:07:34,001-->00:07:36,000 say, a LAN data center infrastructure, what 153 00:07:36,001-->00:07:41,000 technologies are we really discussing in that core layer? 154 00:07:41,001-->00:07:45,000 The core layer of the layered modular approach in a Cisco 155 00:07:45,001-->00:07:47,000 environment make sure that we have 156 00:07:47,001-->00:07:49,000 large amounts of bandwidth. 157 00:07:49,001-->00:07:52,000 10 gigabit per second is the standard in the core. 158 00:07:52,001-->00:07:57,000 And we even see 40 and 100 gigabit per second pipes in 159 00:07:57,001-->00:08:00,000 this high-high bandwidth environment. 160 00:08:00,001-->00:08:04,000 Administrative domains and policies are sketched out, so 161 00:08:04,001-->00:08:07,000 that we couldn't have separate cores in our infrastructure 162 00:08:07,001-->00:08:12,000 that help really define the administrative boundaries of 163 00:08:12,001-->00:08:13,000 our environment. 164 00:08:13,001-->00:08:18,000 And also the core can really help us implement new high 165 00:08:18,001-->00:08:22,000 speed data center technologies that may result from future 166 00:08:22,001-->00:08:24,000 developments in our organization. 167 00:08:24,001-->00:08:27,000 Now while these layers are awesome and each can have 168 00:08:27,001-->00:08:29,000 their own particular functions-- 169 00:08:29,001-->00:08:31,000 as we've sketched out for you-- 170 00:08:31,001-->00:08:34,000 I need you to be perfectly clear on something. 171 00:08:34,001-->00:08:39,000 Many, many organizations today-- both in their LAN and 172 00:08:39,001-->00:08:41,000 they're SAN designs-- 173 00:08:41,001-->00:08:44,000 they are doing what we call a collapsed core. 174 00:08:44,001-->00:08:46,000 What does this mean? 175 00:08:46,001-->00:08:50,000 It means the aggregation layer is moved up into the core. 176 00:08:50,001-->00:08:54,000 So whenever you hear collapsed core, I want you to realize we 177 00:08:54,001-->00:08:59,000 were talking about a design that has core layered devices, 178 00:08:59,001-->00:09:02,000 and then it has access layered devices. 179 00:09:02,001-->00:09:07,000 So we really just define a core and an access. 180 00:09:07,001-->00:09:11,000 This can be done with Layer 3 throughout. 181 00:09:11,001-->00:09:15,000 This can be done with a mix of Layer 3 and Layer 2. 182 00:09:15,001-->00:09:17,000 Layer 3 traditionally being done in the core. 183 00:09:17,001-->00:09:20,000 And Layer 2 being done out at the access layer. 184 00:09:20,001-->00:09:24,000 So please keep in mind that in both Local Area Network 185 00:09:24,001-->00:09:28,000 designs and in Storage Area Network designs, we can go 186 00:09:28,001-->00:09:31,000 with a collapsed core approach. 187 00:09:31,001-->00:09:34,000 The minute you hear collapsed core, I want you thinking of 188 00:09:34,001-->00:09:38,000 just that two layer core and access design. 189 00:09:38,001-->00:09:42,000 Now as promised, let's talk about Cisco's Data Center 3.0 190 00:09:42,001-->00:09:43,000 initiative a little bit. 191 00:09:43,001-->00:09:47,000 This is a nice preview of what we're going to be dealing with 192 00:09:47,001-->00:09:48,000 in depth in this course. 193 00:09:48,001-->00:09:51,000 When it comes to the 3.0 Data Center, Cisco really 194 00:09:51,001-->00:09:54,000 emphasizes virtualization. 195 00:09:54,001-->00:09:57,000 When you say virtualization, it means different things to 196 00:09:57,001-->00:09:58,000 different people. 197 00:09:58,001-->00:10:01,000 For instance, if you have a VMware background, you would 198 00:10:01,001-->00:10:04,000 immediately think about virtualization in your server 199 00:10:04,001-->00:10:05,000 environment. 200 00:10:05,001-->00:10:09,000 You would think about perhaps a C-series rack mounted server 201 00:10:09,001-->00:10:12,000 from Cisco that is actually running many different 202 00:10:12,001-->00:10:16,000 operating systems thanks to the VMware hypervisor. 203 00:10:16,001-->00:10:19,000 While certainly we're going to deal with that concept in this 204 00:10:19,001-->00:10:21,000 course, we don't just stop there. 205 00:10:21,001-->00:10:25,000 We're talking virtualization in the network environment-- 206 00:10:25,001-->00:10:29,000 something like the 1,000V from Cisco Systems. 207 00:10:29,001-->00:10:35,000 And we talk about things like Cisco's VN-Link technology. 208 00:10:35,001-->00:10:37,000 We're going to talk about this a lot in 209 00:10:37,001-->00:10:39,000 this particular course. 210 00:10:39,001-->00:10:42,000 What this means is when we have one of these-- let's say 211 00:10:42,001-->00:10:45,000 it's a C-series rack mounted server and it's got different 212 00:10:45,001-->00:10:49,000 VMs was running on top of it. 213 00:10:49,001-->00:10:54,000 When each of these VMs is communicating through a single 214 00:10:54,001-->00:10:58,000 10 gigabit per second pipe, we want to be able to track the 215 00:10:58,001-->00:11:03,000 traffic of that individual VM as it is moving through our 216 00:11:03,001-->00:11:05,000 network infrastructure. 217 00:11:05,001-->00:11:07,000 This is what VN-link is all about-- 218 00:11:07,001-->00:11:11,000 to literally be able to tag and distinguish the traffic of 219 00:11:11,001-->00:11:15,000 one virtual machine from another virtual machine. 220 00:11:15,001-->00:11:17,000 So virtualization. 221 00:11:17,001-->00:11:20,000 Yes, it's going to be very much present in our modern 222 00:11:20,001-->00:11:21,000 data center. 223 00:11:21,001-->00:11:23,000 And we'll be dealing with it throughout 224 00:11:23,001-->00:11:25,000 this CBT Nugget course. 225 00:11:25,001-->00:11:29,000 As I alluded to in this particular Nugget, the fabric 226 00:11:29,001-->00:11:30,000 is unified. 227 00:11:30,001-->00:11:33,000 This is thanks to technologies like fibre 228 00:11:33,001-->00:11:35,000 channel over Ethernet. 229 00:11:35,001-->00:11:38,000 We'll talk about data center bridging in here. 230 00:11:38,001-->00:11:42,000 We'll talk about iSCSI technology in here. 231 00:11:42,001-->00:11:46,000 So all these technologies are going to be defined and 232 00:11:46,001-->00:11:51,000 supported by Cisco in order to marry the traffic of the LAN 233 00:11:51,001-->00:11:55,000 and the Storage Area Networking wherever we need to 234 00:11:55,001-->00:11:57,000 do in our data center environment. 235 00:11:57,001-->00:12:01,000 And then we have unified computing that is available 236 00:12:01,001-->00:12:02,000 from Cisco. 237 00:12:02,001-->00:12:07,000 This is going to allow us to do a heavy, heavy intense 238 00:12:07,001-->00:12:09,000 amount of virtualization. 239 00:12:09,001-->00:12:14,000 But it's also going to enable us to very, very reliably 240 00:12:14,001-->00:12:19,000 connect many different servers into the LAN and SAN 241 00:12:19,001-->00:12:21,000 infrastructure. 242 00:12:21,001-->00:12:23,000 So we're going to bring the intelligence and the 243 00:12:23,001-->00:12:26,000 information that's in the LAN and the SAN. 244 00:12:26,001-->00:12:31,000 And we're going give it easy access to the server blades 245 00:12:31,001-->00:12:33,000 that are wanting to consume this information. 246 00:12:33,001-->00:12:38,000 If you have no experience with the Unified Computing System 247 00:12:38,001-->00:12:40,000 of Cisco Systems, then don't worry. 248 00:12:40,001-->00:12:42,000 You're in the right place. 249 00:12:42,001-->00:12:46,000 In this particular course, I'll walk you through this UCS 250 00:12:46,001-->00:12:51,000 system, and you can see why it is such an amazing product 251 00:12:51,001-->00:12:52,000 line from Cisco Systems. 252 00:12:52,001-->00:12:56,000 You're going to be able to deploy servers in your 253 00:12:56,001-->00:13:00,000 infrastructure completely ready and raring to go for 254 00:13:00,001-->00:13:01,000 particular functions. 255 00:13:01,001-->00:13:03,000 Maybe it's e-commerce. 256 00:13:03,001-->00:13:05,000 Maybe it's database. 257 00:13:05,001-->00:13:06,000 Maybe it's-- 258 00:13:06,001-->00:13:09,000 I don't know-- some financial analysis. 259 00:13:09,001-->00:13:12,000 You'll be able to deploy these servers and have them ready 260 00:13:12,001-->00:13:15,000 with just a few clicks of the mouse. 261 00:13:15,001-->00:13:19,000 So did we cover information in this particular Nugget that is 262 00:13:19,001-->00:13:20,000 certification relevant? 263 00:13:20,001-->00:13:21,000 We sure did. 264 00:13:21,001-->00:13:25,000 So as such, let's do some sample review questions. 265 00:13:25,001-->00:13:27,000 These are the types of multiple choice that you could 266 00:13:27,001-->00:13:30,000 certainly see in your exam environment. 267 00:13:30,001-->00:13:32,000 Which two are not advantages of a 268 00:13:32,001-->00:13:34,000 modular data center design? 269 00:13:34,001-->00:13:36,000 We have to choose two here. 270 00:13:36,001-->00:13:39,000 Two of these are not necessarily advantages that we 271 00:13:39,001-->00:13:43,000 would get when we shoot for modularity in the data center. 272 00:13:43,001-->00:13:47,000 Resilience, ease of management, complexity, and 273 00:13:47,001-->00:13:49,000 scalability. 274 00:13:49,001-->00:13:54,000 Well, we said that when we do a modular data center design, 275 00:13:54,001-->00:13:58,000 it adds to the resiliency and scalability. 276 00:13:58,001-->00:14:02,000 So the two here that aren't really advantages would be 277 00:14:02,001-->00:14:04,000 ease of management and complexity. 278 00:14:04,001-->00:14:07,000 Look, we love the ease of management. 279 00:14:07,001-->00:14:11,000 But when we do a modular design, it really doesn't lead 280 00:14:11,001-->00:14:13,000 itself to ease of management. 281 00:14:13,001-->00:14:16,000 In fact, if anything, it makes our lives as managers all the 282 00:14:16,001-->00:14:17,000 more complex. 283 00:14:17,001-->00:14:22,000 And complexity's another one. 284 00:14:22,001-->00:14:27,000 The fact that we do increase the complexity of our design 285 00:14:27,001-->00:14:29,000 isn't a good thing, really. 286 00:14:29,001-->00:14:34,000 But adding to the complexity of our design helps give us 287 00:14:34,001-->00:14:37,000 the resilience and the scalability that 288 00:14:37,001-->00:14:38,000 we're looking for. 289 00:14:38,001-->00:14:41,000 So think carefully. 290 00:14:41,001-->00:14:44,000 Don't answer to quickly when it comes to these questions 291 00:14:44,001-->00:14:50,000 about design modularity and the three layered architecture 292 00:14:50,001-->00:14:53,000 of core aggregation and access that we'll 293 00:14:53,001-->00:14:55,000 run into in the exam. 294 00:14:55,001-->00:14:56,000 Let's take a look at another one. 295 00:14:56,001-->00:15:00,000 What are two features we might find in the data center 296 00:15:00,001-->00:15:01,000 aggregation layer? 297 00:15:01,001-->00:15:04,000 Again, our job here is to choose two. 298 00:15:04,001-->00:15:09,000 Security, QoS marking, various services, 299 00:15:09,001-->00:15:11,000 or high speed switching. 300 00:15:11,001-->00:15:13,000 Wow, what a tricky question. 301 00:15:13,001-->00:15:16,000 We certainly might find QoS at the 302 00:15:16,001-->00:15:18,000 aggregation layer, for sure. 303 00:15:18,001-->00:15:21,000 But it really would typically be marking. 304 00:15:21,001-->00:15:24,000 This is something we would find at the 305 00:15:24,001-->00:15:26,000 access layer instead. 306 00:15:26,001-->00:15:29,000 We certainly could have high speed switching, but this is 307 00:15:29,001-->00:15:34,000 more likely for a description of what goes on in our core 308 00:15:34,001-->00:15:37,000 layer of the infrastructure. 309 00:15:37,001-->00:15:41,000 So the best answer, I believe, certainly we can find access 310 00:15:41,001-->00:15:44,000 controls and security mechanisms down at the 311 00:15:44,001-->00:15:47,000 aggregation layer and a lot of other various services. 312 00:15:47,001-->00:15:52,000 One I mentioned was network analysis modules that could be 313 00:15:52,001-->00:15:56,000 inserted here for analyzing the traffic that is coursing 314 00:15:56,001-->00:16:00,000 through the veins of our modern data center. 315 00:16:00,001-->00:16:05,000 Which two layers result in the collapsed core design? 316 00:16:05,001-->00:16:06,000 Do you remember this? 317 00:16:06,001-->00:16:12,000 When we collapse the core, we end up with the core layer and 318 00:16:12,001-->00:16:14,000 the access layer. 319 00:16:14,001-->00:16:18,000 Another way to solve this, by the way, is to realize that 320 00:16:18,001-->00:16:20,000 distribution and aggregation are a 321 00:16:20,001-->00:16:22,000 description of the same layer. 322 00:16:22,001-->00:16:25,000 Some people call the aggregation layer actually the 323 00:16:25,001-->00:16:27,000 distribution layer. 324 00:16:27,001-->00:16:33,000 You'll often see it oftentimes too as the policy-based 325 00:16:33,001-->00:16:34,000 control layer. 326 00:16:34,001-->00:16:37,000 And all of these are trying to describe 327 00:16:37,001-->00:16:38,000 that particular layer. 328 00:16:38,001-->00:16:42,000 If you have two of the options that are the same thing, it's 329 00:16:42,001-->00:16:44,000 probably not going to be right. 330 00:16:44,001-->00:16:46,000 So anyways, this was pretty easy. 331 00:16:46,001-->00:16:49,000 We know that when we collapse the core, obviously we get a 332 00:16:49,001-->00:16:50,000 core layer. 333 00:16:50,001-->00:16:56,000 And the only other layer that exists is that access layer. 334 00:16:56,001-->00:17:00,000 So congratulations you just survived your first Nugget of 335 00:17:00,001-->00:17:02,000 content in this course. 336 00:17:02,001-->00:17:05,000 And we started out mild didn't we? 337 00:17:05,001-->00:17:08,000 Sure, we took a look at the segregation of Local Area 338 00:17:08,001-->00:17:11,000 Network and Storage Area Network traffic. 339 00:17:11,001-->00:17:14,000 And you now really understand why traditionally that 340 00:17:14,001-->00:17:16,000 segregation has taken place. 341 00:17:16,001-->00:17:19,000 One of the big topics there we saw was flow control. 342 00:17:19,001-->00:17:23,000 And Storage Area Networking is really intolerant of the 343 00:17:23,001-->00:17:27,000 approach they could lead to drooped packets that we would 344 00:17:27,001-->00:17:30,000 find in the traditional Ethernet based LAN. 345 00:17:30,001-->00:17:32,000 We talk about that layered architecture-- 346 00:17:32,001-->00:17:36,000 that core aggregation and access approach-- 347 00:17:36,001-->00:17:40,000 that's Cisco has always used, and that moves right each of 348 00:17:40,001-->00:17:41,000 the data center environment. 349 00:17:41,001-->00:17:45,000 And then we wrapped it up with a nice preview of topics that 350 00:17:45,001-->00:17:47,000 we'll see in the rest of this course. 351 00:17:47,001-->00:17:50,000 We talked about the three pronged approach of Data 352 00:17:50,001-->00:17:51,000 Center 3.0. 353 00:17:51,001-->00:17:52,000 Do you remember it? 354 00:17:52,001-->00:17:55,000 It was a heavy dose of virtualization. 355 00:17:55,001-->00:18:00,000 It was our wonderful unified fabric, which is really, 356 00:18:00,001-->00:18:04,000 really exemplified by a technology called fibre 357 00:18:04,001-->00:18:06,000 channel over Ethernet. 358 00:18:06,001-->00:18:09,000 And then finally, it also consists of the Unified 359 00:18:09,001-->00:18:11,000 Computing System. 360 00:18:11,001-->00:18:15,000 Again, we have Nuggets dedicated to those various 361 00:18:15,001-->00:18:18,000 topics coming up in this particular course. 362 00:18:18,001-->00:18:20,000 Well I hope this has been informative for you. 363 00:18:20 And I'd like to thank you for viewing.