WEBVTT 00:00:00.000 --> 00:00:15.000 So now we are going to talk about LISP and VXLAN from the perspective of next-gen networking. 00:00:15.000 --> 00:00:23.000 Let me ask you first, is anybody using LISP at all or VXLAN at all? 00:00:23.000 --> 00:00:28.000 If you are, type in yes. If you're typing no. If you don't know, even know what I'm talking about, type in question marks. 00:00:28.000 --> 00:00:35.000 I'd like to get an idea of how many people even know what we're talking about. 00:00:35.000 --> 00:00:42.000 So let me set the stage for you first and foremost. 00:00:42.000 --> 00:00:54.000 There is a new form of networking that exists called Software Defined Access, SDAccess. 00:00:55.000 --> 00:01:04.000 Software Defined Networking, but Cisco, for their enterprise environment, calls it Software Defined Access. 00:01:04.000 --> 00:01:16.000 When you deploy SDAccess in the world of Cisco, there are two protocols that you need to be very familiar with. 00:01:16.000 --> 00:01:21.000 They are the two protocols that make the magic happen. 00:01:21.000 --> 00:01:24.000 LISP and VXLAN. 00:01:24.000 --> 00:01:30.000 However, none of these protocols were invented originally for the purpose of SDAccess. 00:01:30.000 --> 00:01:32.000 Let's be clear about that. 00:01:32.000 --> 00:01:37.000 LISP was invented for something totally different, and we decided to just use it for SDAccess. 00:01:37.000 --> 00:01:41.000 VXLAN was invented for what? Data centers. 00:01:41.000 --> 00:01:50.000 Data centers to solve VLAN problems in the data center, and so they came up with VXLAN for the data centers. 00:01:50.000 --> 00:01:56.000 But see, now we can use both of these in our enterprise campus networks with SDAccess. 00:01:56.000 --> 00:02:05.000 And so I'm going to teach you about LISP and VXLAN here, and then in our next discussion, we'll talk about SDAccess. 00:02:05.000 --> 00:02:12.000 So if you struggle with the concept of SDAccess, more than likely it has to do with your struggling of the concept of LISP and VXLAN. 00:02:12.000 --> 00:02:18.000 So make sure that you know LISP, VXLAN, and SDAccess. 00:02:19.000 --> 00:02:24.000 Together as a group, that'll make you understand them best, and that's what I'm going to do here today. 00:02:24.000 --> 00:02:26.000 I'm going to teach it to you from that perspective. 00:02:26.000 --> 00:02:32.000 You'll learn about LISP, but I'm going to focus on enterprise implementation of LISP. 00:02:32.000 --> 00:02:38.000 So we're going to constantly go back to our enterprise campus and diagram and diagram and diagram here today. 00:02:38.000 --> 00:02:42.000 Now, your goal for the exam is what? Understand what LISP is. 00:02:42.000 --> 00:02:47.000 Pick terms and definitions out of a lineup for LISP. 00:02:47.000 --> 00:02:48.000 Same thing with VXLAN. 00:02:48.000 --> 00:02:54.000 So your goal is to know the terms and definitions for LISP and VXLAN and have a high-level understanding of what it is, 00:02:54.000 --> 00:02:59.000 why we use it, why we care about it today, and why many of you may not use it going forward. 00:02:59.000 --> 00:03:02.000 Okay, that won't be on the exam, but you'll say, like, I'm really just learning this for the exam. 00:03:02.000 --> 00:03:03.000 Yeah, you are. 00:03:03.000 --> 00:03:04.000 But you never know. 00:03:04.000 --> 00:03:06.000 Five years from now, you might be in an environment that needs it. 00:03:06.000 --> 00:03:10.000 So at least you've got the certification to say, hi, I learned it at some point, well, part of it anyways. 00:03:10.000 --> 00:03:12.000 And then SDAccess, same idea. 00:03:12.000 --> 00:03:15.000 A lot of you will go like, wow, this is crazy, just like with TrustSec. 00:03:15.000 --> 00:03:18.000 But, you see, TrustSec and SDAccess go together. 00:03:18.000 --> 00:03:24.000 So TrustSec, SDAccess, LISP, VXLAN, they're all part of this new paradigm of networking. 00:03:24.000 --> 00:03:27.000 So, first of all, what is LISP? 00:03:27.000 --> 00:03:39.000 Okay, so LISP is a protocol that stands for Location Slash ID Separation Protocol. 00:03:39.000 --> 00:03:44.000 Think about its name for just a second. 00:03:44.000 --> 00:03:49.000 Location Slash ID Separation Protocol. 00:03:49.000 --> 00:03:51.000 What do you think this protocol is about? 00:03:51.000 --> 00:03:57.000 Separating locations from identifications. 00:03:57.000 --> 00:03:59.000 Okay, what does that mean? 00:03:59.000 --> 00:04:00.000 You're going to learn about that momentarily. 00:04:00.000 --> 00:04:02.000 But why was it invented? 00:04:02.000 --> 00:04:04.000 It was invented to create. 00:04:05.000 --> 00:04:11.000 It was invented because of scalability and addressing problems on the Internet. 00:04:11.000 --> 00:04:12.000 That's right. 00:04:12.000 --> 00:04:21.000 It was to solve Internet-related problems, problems related to scalability and addressing. 00:04:21.000 --> 00:04:24.000 What were the problems of scalability and addressing? 00:04:24.000 --> 00:04:26.000 Well, location and ID. 00:04:26.000 --> 00:04:31.000 If you are here on the Internet, that is your location and you have an ID. 00:04:31.000 --> 00:04:35.000 If you go somewhere else, you can't take any of that with you, 00:04:35.000 --> 00:04:45.000 which really required us to design an Internet that was very location-based. 00:04:45.000 --> 00:04:48.000 And so, if you're here, there's your location, there's your ID. 00:04:48.000 --> 00:04:50.000 But if you go somewhere else, you can't take that with you. 00:04:50.000 --> 00:04:53.000 LISP solves that problem for us. 00:04:53.000 --> 00:05:01.000 So, LISP is both a routing architecture itself, as well as a data and control plane protocol. 00:05:01.000 --> 00:05:04.000 And so, LISP gave us the ability to solve the problems of the Internet 00:05:04.000 --> 00:05:07.000 that had, like, aggregation problems, traffic engineering problems, 00:05:07.000 --> 00:05:10.000 multi-homing problems, instability problems, mobility problems. 00:05:10.000 --> 00:05:12.000 That's why LISP was invented. 00:05:12.000 --> 00:05:16.000 Okay, you don't need to know that for the exam, but that's why it was invented. 00:05:16.000 --> 00:05:18.000 But now, we use it where? 00:05:18.000 --> 00:05:20.000 In our data centers, in our campus networks, in our branch offices, 00:05:21.000 --> 00:05:28.000 in our next-gen wide-area networking solutions, in our service provider cores. 00:05:28.000 --> 00:05:29.000 Why are we talking about it here today? 00:05:29.000 --> 00:05:32.000 Because LISP is part of SD Access. 00:05:32.000 --> 00:05:35.000 LISP is part of our campus networks. 00:05:35.000 --> 00:05:38.000 LISP is part of this growing movement of next-gen networking 00:05:38.000 --> 00:05:44.000 with better security and zero-trust architectures. 00:05:44.000 --> 00:05:46.000 So, as I mentioned a little earlier, LISP is what? 00:05:46.000 --> 00:05:48.000 Location and ID separation. 00:05:48.000 --> 00:05:50.000 So, think about your traditional architecture. 00:05:50.000 --> 00:05:55.000 Your traditional architecture, whether it's on the Internet or in your campus environment, 00:05:55.000 --> 00:05:59.000 if you are here, this is your location, this is your ID. 00:05:59.000 --> 00:06:02.000 And no matter what, that ID is only available in that location. 00:06:02.000 --> 00:06:06.000 If you go somewhere else, your identification changes. 00:06:06.000 --> 00:06:09.000 So, think about it here. 00:06:09.000 --> 00:06:12.000 If you're here, this is you. 00:06:14.000 --> 00:06:16.000 That's your location. 00:06:17.000 --> 00:06:21.000 VLAN 10, let's say. 00:06:21.000 --> 00:06:23.000 This is your subnet. 00:06:25.000 --> 00:06:27.000 And you are 10.0.0.5. 00:06:27.000 --> 00:06:31.000 So, your location and your ID are tied together. 00:06:33.000 --> 00:06:37.000 You are identified by your network and your IP address. 00:06:37.000 --> 00:06:39.000 Tightly coupled together. 00:06:40.000 --> 00:06:42.000 But if you move here, 00:06:43.000 --> 00:06:44.000 Oops. 00:06:44.000 --> 00:06:48.000 If you move here, and that's where you go, 00:06:48.000 --> 00:06:52.000 you unplug and you plug back in, or you connect to a wireless access point down there. 00:06:53.000 --> 00:06:55.000 Now you are in, what? 00:06:55.000 --> 00:06:57.000 Let's say VLAN 50. 00:06:57.000 --> 00:07:01.000 10.0.50.0.24. 00:07:01.000 --> 00:07:07.000 And you are 10.0.50.24. 00:07:08.000 --> 00:07:12.000 Let's put 20 instead, because I don't want it to look like the subnet mask. 00:07:13.000 --> 00:07:17.000 So, now your location has changed. 00:07:17.000 --> 00:07:20.000 Your ID has also changed. 00:07:20.000 --> 00:07:24.000 So, what else, folks, do you think probably changed as well? 00:07:24.000 --> 00:07:27.000 Something we talked about in our last session. 00:07:27.000 --> 00:07:30.000 Not session, video, conversation. 00:07:32.000 --> 00:07:34.000 Your security posture, right? 00:07:35.000 --> 00:07:38.000 Your security policies have changed as well, possibly. 00:07:38.000 --> 00:07:40.000 So, this is not good. 00:07:40.000 --> 00:07:45.000 It's impossible nowadays to invoke end-to-end security in policies 00:07:45.000 --> 00:07:49.000 and this type of mindset and this type of architecture. 00:07:49.000 --> 00:07:54.000 But see, with Lisp now, if we use Lisp in our environment, what can I do? 00:07:55.000 --> 00:08:00.000 I can separate where you are from who you are. 00:08:01.000 --> 00:08:10.000 So, right now, you might be 10.0.0.5 in this location. 00:08:10.000 --> 00:08:16.000 But if you move here, you can still be. 00:08:16.000 --> 00:08:23.000 You can still be 10.0.0.5, even though you are not in your location. 00:08:23.000 --> 00:08:24.000 What does that mean? 00:08:24.000 --> 00:08:27.000 It means your ID follows you where you go. 00:08:28.000 --> 00:08:31.000 And so, when you think about TrustSec, right, TrustSec is part of that. 00:08:31.000 --> 00:08:35.000 When you log in with your username and password and your contextual ID, 00:08:35.000 --> 00:08:39.000 the device, et cetera, et cetera, is all being authenticated, right? 00:08:39.000 --> 00:08:43.000 We don't care about your, like, IP address and things like that. 00:08:43.000 --> 00:08:46.000 We can, but, like, we don't care necessarily about that. 00:08:46.000 --> 00:08:50.000 We don't even care where you are when it comes to your security policies. 00:08:51.000 --> 00:08:58.000 But from the concept right now of Lisp, I can separate out who you are from where you are. 00:08:58.000 --> 00:09:02.000 So, that way, you can always be the same thing 00:09:02.000 --> 00:09:07.000 and always have the same policies applied to you no matter where you are. 00:09:08.000 --> 00:09:14.000 Can anybody name one other network that you know about that already does it this way, 00:09:14.000 --> 00:09:18.000 that you use every single day? 00:09:19.000 --> 00:09:20.000 That's right. 00:09:20.000 --> 00:09:24.000 There's another network out there that does it this way that you use every single day. 00:09:24.000 --> 00:09:26.000 And we don't even realize it's doing this. 00:09:27.000 --> 00:09:29.000 Cellular network, folks. 00:09:29.000 --> 00:09:31.000 Cell phones. 00:09:31.000 --> 00:09:34.000 This one's totally coming in handy, and I'm telling you, 00:09:34.000 --> 00:09:38.000 if you have cell phones every day, then that's where you spend 00:09:39.000 --> 00:09:41.000 all of your stuff. 00:09:41.000 --> 00:09:43.000 Like, what do you do every day, man? 00:09:43.000 --> 00:09:44.000 That's the best thing. 00:09:44.000 --> 00:09:46.000 Who knows? 00:09:46.000 --> 00:09:48.000 What are you doing every day? 00:09:48.000 --> 00:09:49.000 Cell phones. 00:09:49.000 --> 00:09:51.000 Who knows? 00:09:51.000 --> 00:09:53.000 Cell phones. 00:09:53.000 --> 00:09:54.000 When on a fast break, 00:09:54.000 --> 00:09:56.000 cell phones. 00:09:56.000 --> 00:09:59.000 Think about it this way. 00:09:59.000 --> 00:10:01.000 Right now, you have your phone, 00:10:01.000 --> 00:10:05.000 and let's say you are in your hometown. 00:10:05.000 --> 00:10:11.000 Right now, you have a phone number with an area code in your hometown. 00:10:11.000 --> 00:10:17.000 Your location and your ID are tied together right now. 00:10:17.000 --> 00:10:24.000 But if you travel to Vegas right now, 00:10:24.000 --> 00:10:26.000 unless you're living in Vegas, sorry, 00:10:26.000 --> 00:10:28.000 then you don't qualify for this scenario, 00:10:28.000 --> 00:10:32.000 but if you travel from where you are right now and you go to Vegas, 00:10:32.000 --> 00:10:40.000 does your phone number change, folks, yes or no? 00:10:40.000 --> 00:10:44.000 Nope. 00:10:44.000 --> 00:10:47.000 Does your location change? 00:10:47.000 --> 00:10:54.000 Yep. 00:10:54.000 --> 00:10:57.000 So what has to happen? 00:10:57.000 --> 00:11:01.000 You leave where you are, and when you leave, 00:11:01.000 --> 00:11:05.000 do the cell towers know that you are leaving? 00:11:05.000 --> 00:11:07.000 Do the cell towers know you? 00:11:07.000 --> 00:11:08.000 Yes. 00:11:08.000 --> 00:11:11.000 And every time you connect to a different cell tower, 00:11:11.000 --> 00:11:17.000 the cell tower has to tell the centralized server that. 00:11:17.000 --> 00:11:20.000 So that way if somebody tries to call you, 00:11:20.000 --> 00:11:24.000 the centralized server can route to the right cell tower, 00:11:24.000 --> 00:11:26.000 that will get to you. 00:11:26.000 --> 00:11:28.000 And then as you continue to move, 00:11:28.000 --> 00:11:29.000 let's say you're even on the phone, 00:11:29.000 --> 00:11:33.000 could you register with another cell tower as you keep going along? 00:11:33.000 --> 00:11:38.000 And that tower tells the server, yeah, of course. 00:11:38.000 --> 00:11:40.000 Let's say you hopped on a plane. 00:11:40.000 --> 00:11:41.000 You're in the air. 00:11:41.000 --> 00:11:42.000 You're not connected to anything. 00:11:42.000 --> 00:11:43.000 You land. 00:11:43.000 --> 00:11:45.000 You connect to a cell tower. 00:11:45.000 --> 00:11:48.000 That cell tower tells the central server, hey, 00:11:48.000 --> 00:11:52.000 this phone number is now registered to me. 00:11:52.000 --> 00:11:54.000 The server updates itself. 00:11:54.000 --> 00:11:57.000 You are now in a different location, but you are the same ID. 00:11:57.000 --> 00:12:01.000 And the network adjusts to get to you. 00:12:01.000 --> 00:12:02.000 Same idea. 00:12:02.000 --> 00:12:04.000 Same idea. 00:12:04.000 --> 00:12:06.000 So what does that mean? 00:12:06.000 --> 00:12:09.000 It means when you connect to the network here, 00:12:09.000 --> 00:12:20.000 this switch has to notify a centralized device that you are connected there. 00:12:20.000 --> 00:12:23.000 And if you move, 00:12:23.000 --> 00:12:31.000 then this switch has to tell that centralized device that you are now there. 00:12:31.000 --> 00:12:36.000 And that centralized device keeps a database of where everyone is in the 00:12:36.000 --> 00:12:38.000 environment. 00:12:38.000 --> 00:12:46.000 And even if I go home and I plug in at home or I plug in a remote office, 00:12:46.000 --> 00:12:48.000 same thing is true. 00:12:48.000 --> 00:12:50.000 Raymond's now over there, 00:12:50.000 --> 00:12:53.000 connected over there with that particular device, 00:12:53.000 --> 00:13:01.000 I can apply my trust tech policies and everything else that go along that as well. 00:13:01.000 --> 00:13:04.000 That is a very flexible, scalable network. 00:13:04.000 --> 00:13:05.000 All right. 00:13:05.000 --> 00:13:08.000 But that requires a little bit of architectural changing to make it work, folks. 00:13:08.000 --> 00:13:09.000 It really does. 00:13:09.000 --> 00:13:10.000 It really does. 00:13:10.000 --> 00:13:14.000 So look at our layer two, layer three boundary right now. 00:13:14.000 --> 00:13:20.000 Although we could implement LISP as such, we typically don't. 00:13:21.000 --> 00:13:25.000 It's a less practice way to do it to ensure that you get the greatest enforcement, 00:13:25.000 --> 00:13:26.000 the greatest coverage, 00:13:26.000 --> 00:13:27.000 the greatest routing, 00:13:27.000 --> 00:13:29.000 the greatest everything. 00:13:29.000 --> 00:13:30.000 When it all comes down, 00:13:30.000 --> 00:13:31.000 you gotta move that boundary line. 00:13:31.000 --> 00:13:34.000 You wanna move that boundary line down to here. 00:13:34.000 --> 00:13:35.000 You wanna move that boundary line here. 00:13:35.000 --> 00:13:36.000 You wanna move it here. 00:13:36.000 --> 00:13:37.000 You wanna move it here. 00:13:37.000 --> 00:13:38.000 For example, 00:13:38.000 --> 00:13:40.000 you wanna get it as far down as you can. 00:13:40.000 --> 00:13:42.000 Well there was no layer two there anyway so it was all layer three down there. 00:13:42.000 --> 00:13:43.000 Okay. 00:13:43.000 --> 00:13:44.000 But you gotta move that boundary line. 00:13:44.000 --> 00:13:45.000 You gotta get it down, 00:13:45.000 --> 00:13:46.000 down, 00:13:46.000 --> 00:13:47.000 down all the way down. 00:13:47.000 --> 00:13:48.000 Okay. 00:13:48.000 --> 00:13:49.000 So we moved that boundary line down. 00:13:49.000 --> 00:13:50.000 But also, 00:13:50.000 --> 00:13:52.000 now what we do is we create what is called a fabric. 00:13:52.000 --> 00:13:58.000 And that fabric is an environment that we can virtualize networks on top of this. 00:13:58.000 --> 00:13:59.000 Right. 00:13:59.000 --> 00:14:02.000 So this relies on a lot of virtualization to make it all work. 00:14:02.000 --> 00:14:03.000 So when you look at this, 00:14:03.000 --> 00:14:05.000 we've now moved our boundary lines down. 00:14:05.000 --> 00:14:11.000 And we've implemented multi-layer switches instead of just pure layer two switches. 00:14:11.000 --> 00:14:13.000 There are now multi-layer switches down there. 00:14:13.000 --> 00:14:14.000 And our fabric, 00:14:14.000 --> 00:14:17.000 because this is gonna be SD access as I was talking about, 00:14:17.000 --> 00:14:18.000 all right, 00:14:18.000 --> 00:14:20.000 we are talking about just the enterprise right now, 00:14:20.000 --> 00:14:21.000 not our data center. 00:14:21.000 --> 00:14:23.000 So our data center is still gonna be the ACI, 00:14:23.000 --> 00:14:26.000 the applications centric infrastructure. 00:14:26.000 --> 00:14:27.000 It's called ACI, 00:14:27.000 --> 00:14:28.000 application centric infrastructure. 00:14:28.000 --> 00:14:30.000 But for our enterprise network, 00:14:30.000 --> 00:14:33.000 it's got a nice little fancy name called SD access instead. 00:14:33.000 --> 00:14:39.000 So you can see there's a little bit of a shift here now in what's going on. 00:14:39.000 --> 00:14:42.000 But it's important that we have our layer two, 00:14:42.000 --> 00:14:44.000 layer three boundary here instead. 00:14:44.000 --> 00:14:47.000 So does that mean everybody is essentially directly connected to their default gateway? 00:14:47.000 --> 00:14:48.000 Yeah, 00:14:48.000 --> 00:14:49.000 pretty much. 00:14:49.000 --> 00:14:51.000 And this causes a lot of confusion because people are like, 00:14:51.000 --> 00:14:52.000 well, 00:14:52.000 --> 00:14:53.000 then wait, 00:14:53.000 --> 00:14:54.000 wait, 00:14:54.000 --> 00:14:55.000 wait, 00:14:55.000 --> 00:14:56.000 how does this work? 00:14:56.000 --> 00:14:59.000 How do I implement a VLAN that spans multiple then multi-layer switches? 00:14:59.000 --> 00:15:00.000 I can't do that anymore. 00:15:00.000 --> 00:15:01.000 Can I? 00:15:01.000 --> 00:15:02.000 Well, 00:15:02.000 --> 00:15:03.000 that's where something like VXLAN comes into play. 00:15:03.000 --> 00:15:05.000 That's where VXLAN comes into play. 00:15:05.000 --> 00:15:11.000 VXLAN is gonna allow me to interconnect devices together that are part of the same subnet, 00:15:12.000 --> 00:15:15.000 but are not actually connected to the same device. 00:15:15.000 --> 00:15:20.000 So does that even mean that I could have somebody here in VLAN 10 as an example, 00:15:20.000 --> 00:15:22.000 and now somebody here in VLAN 10? 00:15:22.000 --> 00:15:23.000 Sure, 00:15:23.000 --> 00:15:24.000 absolutely. 00:15:24.000 --> 00:15:25.000 I mean, 00:15:25.000 --> 00:15:26.000 in the same subnet too, 00:15:26.000 --> 00:15:27.000 Raymond? 00:15:27.000 --> 00:15:28.000 Yeah. 00:15:28.000 --> 00:15:29.000 What about the same broadcast? 00:15:29.000 --> 00:15:30.000 I mean, 00:15:30.000 --> 00:15:31.000 yeah. 00:15:31.000 --> 00:15:32.000 Wait, 00:15:32.000 --> 00:15:33.000 how does broadcast traffic get across there? 00:15:33.000 --> 00:15:34.000 Because with VXLAN, 00:15:34.000 --> 00:15:35.000 which we'll talk about later, 00:15:35.000 --> 00:15:37.000 that's how we tunnel that traffic through. 00:15:37.000 --> 00:15:41.000 But we can't have VXLAN running until LISP. 00:15:41.000 --> 00:15:48.000 Until LISP builds the network that VXLAN can run on. 00:15:51.000 --> 00:15:53.000 So that's what the two protocols are for. 00:15:55.000 --> 00:15:57.000 We have LISP to build the network, 00:15:57.000 --> 00:15:59.000 VXLAN to route the traffic. 00:15:59.000 --> 00:16:00.000 More on that later. 00:16:01.000 --> 00:16:02.000 Now, 00:16:02.000 --> 00:16:05.000 does LISP need, 00:16:07.000 --> 00:16:10.000 can LISP operate all by itself? 00:16:10.000 --> 00:16:12.000 The answer to that is no. 00:16:12.000 --> 00:16:15.000 What must be running in this network, 00:16:15.000 --> 00:16:16.000 folks, 00:16:16.000 --> 00:16:19.000 before you can even implement LISP? 00:16:19.000 --> 00:16:21.000 Take a wild guess. 00:16:26.000 --> 00:16:27.000 Yes, 00:16:27.000 --> 00:16:30.000 some type of dynamic routing protocol. 00:16:32.000 --> 00:16:34.000 Some type of IGP. 00:16:34.000 --> 00:16:35.000 OSPF, 00:16:35.000 --> 00:16:36.000 EIGRP, 00:16:36.000 --> 00:16:37.000 ISIS, 00:16:37.000 --> 00:16:39.000 those are all possible options. 00:16:41.000 --> 00:16:45.000 So you have to have full connectivity 00:16:45.000 --> 00:16:47.000 from a Layer 3 standpoint 00:16:47.000 --> 00:16:49.000 from here 00:16:50.000 --> 00:16:51.000 to here 00:16:52.000 --> 00:16:53.000 to here 00:16:54.000 --> 00:16:56.000 to here as an example in this case. 00:16:58.000 --> 00:17:03.000 So we're going to be running OSPF or EIGRP or ISIS. 00:17:03.000 --> 00:17:04.000 And actually, 00:17:04.000 --> 00:17:05.000 the recommendation is ISIS, 00:17:05.000 --> 00:17:06.000 by the way, 00:17:06.000 --> 00:17:07.000 folks. 00:17:07.000 --> 00:17:08.000 That is actually the recommendation. 00:17:08.000 --> 00:17:11.000 So I'm pretty sure eventually down the road, 00:17:11.000 --> 00:17:13.000 Encore and in RC, 00:17:13.000 --> 00:17:15.000 we're going to start covering ISIS in those courses 00:17:15.000 --> 00:17:18.000 because if they're introducing SD-AXIS now, 00:17:18.000 --> 00:17:20.000 I'm pretty sure we're going to start learning about ISIS 00:17:20.000 --> 00:17:21.000 for the enterprise now. 00:17:22.000 --> 00:17:23.000 But you can use OSPF, 00:17:23.000 --> 00:17:24.000 you can use the EIGRP, 00:17:24.000 --> 00:17:26.000 but ISIS works better. 00:17:26.000 --> 00:17:28.000 It does because ISIS is a more open, 00:17:28.000 --> 00:17:30.000 flexible protocol, 00:17:30.000 --> 00:17:32.000 and it works really well with SD-AXIS. 00:17:42.000 --> 00:17:43.000 So full connectivity. 00:17:43.000 --> 00:17:44.000 Why? 00:17:44.000 --> 00:17:46.000 Because we want to be able to make sure we can route from here 00:17:46.000 --> 00:17:50.000 to here or from here to here or from here to here 00:17:50.000 --> 00:17:52.000 or from here to here or from here to here 00:17:52.000 --> 00:17:55.000 or from here to here or from here and so on and so forth. 00:17:56.000 --> 00:17:58.000 So we have to make sure we can route to all, 00:17:58.000 --> 00:18:02.000 between all those different devices with our underlying protocol, 00:18:02.000 --> 00:18:03.000 our underlying protocol. 00:18:03.000 --> 00:18:04.000 All right. 00:18:05.000 --> 00:18:07.000 So let's talk about some LISP terminology. 00:18:07.000 --> 00:18:09.000 Now we need to get ready for the certification exam. 00:18:10.000 --> 00:18:11.000 So, for example, 00:18:11.000 --> 00:18:12.000 we have LISP sites. 00:18:13.000 --> 00:18:14.000 That's number one. 00:18:14.000 --> 00:18:15.000 What is a LISP site? 00:18:15.000 --> 00:18:19.000 So a LISP site is where any type of LISP routers 00:18:19.000 --> 00:18:21.000 and endpoints reside. 00:18:22.000 --> 00:18:25.000 A LISP site is where any LISP routers 00:18:25.000 --> 00:18:28.000 and LISP endpoints reside. 00:18:29.000 --> 00:18:31.000 So when you look at this scenario here, 00:18:33.000 --> 00:18:35.000 this is typically how you see LISP represented 00:18:35.000 --> 00:18:37.000 because LISP was designed, what, 00:18:37.000 --> 00:18:38.000 for the Internet originally. 00:18:39.000 --> 00:18:43.000 So a LISP site might be somebody's autonomous system. 00:18:43.000 --> 00:18:46.000 A LISP site might be another autonomous system. 00:18:47.000 --> 00:18:50.000 And when you think about it from the Internet standpoint, 00:18:51.000 --> 00:18:53.000 and then at this LISP site, 00:18:53.000 --> 00:18:56.000 we have a LISP router that connects us up to LISP. 00:18:57.000 --> 00:19:00.000 And so this LISP router is going to have the ability 00:19:00.000 --> 00:19:03.000 to do the LISP-related stuff we need, 00:19:03.000 --> 00:19:05.000 like that LISP router will for that LISP site. 00:19:06.000 --> 00:19:08.000 So a LISP site is where we have routers and endpoints. 00:19:08.000 --> 00:19:11.000 But when you look at it from the SD access standpoint, 00:19:12.000 --> 00:19:14.000 you are actually going to define your LISP site. 00:19:14.000 --> 00:19:18.000 So, for example, this might be a site. 00:19:19.000 --> 00:19:23.000 Notice my entire environment is not the site. 00:19:25.000 --> 00:19:29.000 See, the site is essentially the location. 00:19:30.000 --> 00:19:31.000 Think of it that way. 00:19:31.000 --> 00:19:33.000 The site is essentially the location. 00:19:34.000 --> 00:19:36.000 So I could have another LISP site here, 00:19:36.000 --> 00:19:37.000 and that could be like that. 00:19:38.000 --> 00:19:39.000 We could have a LISP site here. 00:19:40.000 --> 00:19:41.000 We could have a site here. 00:19:43.000 --> 00:19:46.000 And inside that site, yes, will you have your VLAN? 00:19:46.000 --> 00:19:47.000 Yes. 00:19:47.000 --> 00:19:48.000 Will you have your subnet? 00:19:48.000 --> 00:19:49.000 Yes. 00:19:49.000 --> 00:19:50.000 Do you have your broad? 00:19:50.000 --> 00:19:51.000 Yes. 00:19:51.000 --> 00:19:52.000 All right? 00:19:52.000 --> 00:19:53.000 Yes. 00:19:53.000 --> 00:19:55.000 So inside of that site, we are going to have what? 00:19:56.000 --> 00:19:57.000 We're going to have a LISP-speaking router. 00:19:57.000 --> 00:20:00.000 So here is my LISP-speaking router right here. 00:20:01.000 --> 00:20:02.000 It's my multilayer switch. 00:20:03.000 --> 00:20:04.000 In this case, I have two of them here. 00:20:05.000 --> 00:20:06.000 This one has one here. 00:20:07.000 --> 00:20:08.000 This one has two here. 00:20:09.000 --> 00:20:10.000 Those are the LISP-speaking routers. 00:20:11.000 --> 00:20:13.000 And then you have all your end users in there, 00:20:13.000 --> 00:20:16.000 connected to the switch ports on those multilayer switches, 00:20:17.000 --> 00:20:18.000 on layer two interfaces. 00:20:19.000 --> 00:20:22.000 And so would we have our SVI set up right here instead of here now? 00:20:23.000 --> 00:20:24.000 Yes. 00:20:24.000 --> 00:20:25.000 So think about it. 00:20:25.000 --> 00:20:26.000 These are all routed ports. 00:20:26.000 --> 00:20:27.000 Routed ports. 00:20:27.000 --> 00:20:28.000 Routed ports. 00:20:29.000 --> 00:20:30.000 Whereas now the SVI is on here, 00:20:31.000 --> 00:20:34.000 and anybody in access port VLAN 10, VLAN 10, VLAN 10. 00:20:35.000 --> 00:20:36.000 So no more trunks, right? 00:20:36.000 --> 00:20:37.000 There's no trunk links now. 00:20:37.000 --> 00:20:38.000 They're essentially gone. 00:20:40.000 --> 00:20:41.000 I have access ports going down to my end users 00:20:42.000 --> 00:20:44.000 unless I need a trunk that goes down to a server, right? 00:20:44.000 --> 00:20:45.000 Maybe. 00:20:45.000 --> 00:20:46.000 Maybe I need that. 00:20:46.000 --> 00:20:47.000 But in the end, 00:20:47.000 --> 00:20:50.000 I have essentially access ports going to the users, 00:20:50.000 --> 00:20:52.000 and then I have my default gateway as the SVI 00:20:53.000 --> 00:20:54.000 that you're directly connected to. 00:20:55.000 --> 00:20:56.000 No spanning tree protocol. 00:20:57.000 --> 00:20:58.000 I love it. 00:20:58.000 --> 00:20:59.000 No first software density protocols. 00:20:59.000 --> 00:21:00.000 I love it. 00:21:01.000 --> 00:21:03.000 A lot less things I now have to implement. 00:21:03.000 --> 00:21:05.000 But now I've got to learn how to do LISP and VXLAN 00:21:05.000 --> 00:21:06.000 to make all this work. 00:21:07.000 --> 00:21:08.000 I've got to learn about these things called LISP sites. 00:21:09.000 --> 00:21:10.000 So you've got your sites. 00:21:11.000 --> 00:21:12.000 But then what do you have? 00:21:12.000 --> 00:21:13.000 You've got your endpoints. 00:21:13.000 --> 00:21:14.000 So these are two terms I want you to know. 00:21:14.000 --> 00:21:15.000 You've got your endpoints, 00:21:16.000 --> 00:21:19.000 the IP assigned to the actual endpoints. 00:21:20.000 --> 00:21:21.000 So you have a PC. 00:21:21.000 --> 00:21:22.000 Your PC is your endpoint. 00:21:22.000 --> 00:21:23.000 Your phone is your endpoint. 00:21:24.000 --> 00:21:25.000 Your printer is your endpoint. 00:21:26.000 --> 00:21:27.000 They get an endpoint identifier, 00:21:28.000 --> 00:21:29.000 which is the IP address assigned to them 00:21:30.000 --> 00:21:31.000 in that particular site. 00:21:32.000 --> 00:21:35.000 So let's present this as site 10.0.20.0.24. 00:21:36.000 --> 00:21:39.000 Then this device will get 10.0.20.0.24 as an example. 00:21:40.000 --> 00:21:41.000 We go over here. 00:21:41.000 --> 00:21:42.000 We've got 10.0.10.0.24. 00:21:43.000 --> 00:21:45.000 So you're getting 10.0.10.0.24. 00:21:46.000 --> 00:21:48.000 So you get an IP address in your subnet. 00:21:49.000 --> 00:21:50.000 But I want you to notice here 00:21:50.000 --> 00:21:52.000 that there's something called an RLOC. 00:21:53.000 --> 00:21:54.000 An RLOC, a routing locator. 00:21:55.000 --> 00:21:57.000 This is the IP address assigned to the device 00:21:58.000 --> 00:21:59.000 that is making up the routing system. 00:22:00.000 --> 00:22:03.000 This is the IP address assigned to your LISP router. 00:22:04.000 --> 00:22:07.000 So your LISP router needs a very special IP address 00:22:08.000 --> 00:22:12.000 given to it to identify itself on the LISP network. 00:22:17.000 --> 00:22:19.000 And yes, this is something I want to be able 00:22:19.000 --> 00:22:20.000 to route to and from. 00:22:21.000 --> 00:22:23.000 So this is not like your OSPF router ID. 00:22:25.000 --> 00:22:27.000 But this could be a loopback interface, as an example, 00:22:28.000 --> 00:22:29.000 with an IP address on it. 00:22:29.000 --> 00:22:31.000 And that is identified as my RLOC, 00:22:32.000 --> 00:22:35.000 my identifier in my LISP environment. 00:22:38.000 --> 00:22:39.000 So if we go back here. 00:22:41.000 --> 00:22:42.000 Not there. 00:22:42.000 --> 00:22:43.000 If we go back here, 00:22:46.000 --> 00:22:48.000 this would have to have an RLOC. 00:22:49.000 --> 00:22:52.000 So let's say I gave it an RLOC of 192.168.1.1. 00:22:54.000 --> 00:22:57.000 And I gave this one an RLOC of 192.168.1.1. 00:22:57.000 --> 00:23:00.000 And I gave this one an RLOC of 192.168.1.1.1. 00:23:06.000 --> 00:23:09.000 And let's say it was slash 32, the IP address. 00:23:10.000 --> 00:23:12.000 And let's do 192.168.1.2. 00:23:18.000 --> 00:23:20.000 So all of these devices here need RLOCs. 00:23:21.000 --> 00:23:22.000 This does not need an RLOC. 00:23:23.000 --> 00:23:24.000 This does not need an RLOC. 00:23:25.000 --> 00:23:26.000 This does not. 00:23:26.000 --> 00:23:27.000 This does not. 00:23:27.000 --> 00:23:28.000 This does not. 00:23:28.000 --> 00:23:29.000 This does not. 00:23:29.000 --> 00:23:30.000 Why? 00:23:30.000 --> 00:23:32.000 Because they are not part of sites. 00:23:33.000 --> 00:23:36.000 They are part of the underlying routing infrastructure 00:23:37.000 --> 00:23:39.000 that gets you from site to site. 00:23:43.000 --> 00:23:46.000 So LISP is really only running on those edge devices. 00:23:47.000 --> 00:23:49.000 That's really where it's running. 00:23:50.000 --> 00:23:54.000 So RLOC, RLOC, RLOC, RLOC, RLOC, RLOC, RLOC over there, 00:23:55.000 --> 00:23:57.000 and RLOCs right here. 00:23:58.000 --> 00:24:00.000 So wherever you see our defining point, 00:24:01.000 --> 00:24:03.000 like we said, this is our environment here. 00:24:06.000 --> 00:24:08.000 Right now, that's what we're building. 00:24:09.000 --> 00:24:11.000 So all the devices on that red line 00:24:12.000 --> 00:24:13.000 get an RLOC assigned to them. 00:24:14.000 --> 00:24:15.000 Now, here's the cool part. 00:24:16.000 --> 00:24:17.000 You ready for this? 00:24:17.000 --> 00:24:19.000 You run your dynamic routing protocol 00:24:20.000 --> 00:24:21.000 for that IP address. 00:24:22.000 --> 00:24:23.000 What does that mean? 00:24:24.000 --> 00:24:25.000 It means that, for example, 00:24:26.000 --> 00:24:28.000 inject that into OSPF, inject that into EIGRP, 00:24:29.000 --> 00:24:30.000 inject that into ISIS. 00:24:31.000 --> 00:24:32.000 What does that mean? 00:24:33.000 --> 00:24:35.000 Every router now inside of this red box 00:24:36.000 --> 00:24:38.000 learns about these addresses. 00:24:39.000 --> 00:24:41.000 Now we can route to each other, right? 00:24:42.000 --> 00:24:43.000 Now we can route to each other. 00:24:44.000 --> 00:24:45.000 But this is even cooler. 00:24:45.000 --> 00:24:47.000 You never, ever, ever have to teach 00:24:48.000 --> 00:24:50.000 any of these routers in here, 00:24:51.000 --> 00:24:52.000 any of these routers in here, 00:24:53.000 --> 00:24:55.000 about any of your end-user networks. 00:25:04.000 --> 00:25:05.000 Why? 00:25:06.000 --> 00:25:07.000 Because none of these routers 00:25:08.000 --> 00:25:10.000 will ever be routing to your end-user networks. 00:25:11.000 --> 00:25:13.000 They will be routing to your end-user networks 00:25:14.000 --> 00:25:15.000 they will be routing to who? 00:25:16.000 --> 00:25:18.000 They'll be routing to the RLOCs. 00:25:19.000 --> 00:25:20.000 That's right. 00:25:21.000 --> 00:25:22.000 They'll be routing to the RLOCs. 00:25:25.000 --> 00:25:26.000 Not in some ways. 00:25:27.000 --> 00:25:28.000 Erase that. 00:25:29.000 --> 00:25:31.000 It means a smaller routing table in here. 00:25:32.000 --> 00:25:33.000 Way smaller. 00:25:34.000 --> 00:25:35.000 Yes, absolutely. 00:25:36.000 --> 00:25:37.000 Way smaller. 00:25:38.000 --> 00:25:39.000 Yeah. 00:25:40.000 --> 00:25:41.000 Yeah. 00:25:41.000 --> 00:25:42.000 Good vision there. 00:25:42.000 --> 00:25:43.000 Good vision, you're right. 00:25:43.000 --> 00:25:45.000 Way smaller routing tables. 00:25:50.000 --> 00:25:51.000 That's incredible, right? 00:25:51.000 --> 00:25:53.000 That is, when you think about it. 00:25:53.000 --> 00:25:54.000 And this is where people struggle 00:25:54.000 --> 00:25:55.000 because they go, 00:25:55.000 --> 00:25:56.000 then how do I get there? 00:25:56.000 --> 00:25:57.000 I got to teach you that. 00:25:57.000 --> 00:25:58.000 We're not there yet. 00:25:58.000 --> 00:25:59.000 I'll show you. 00:25:59.000 --> 00:26:00.000 I'll show you. 00:26:00.000 --> 00:26:01.000 All right, so, remember, 00:26:01.000 --> 00:26:02.000 that's your endpoint identifier. 00:26:02.000 --> 00:26:03.000 Know that. 00:26:04.000 --> 00:26:05.000 And there's your RLOC. 00:26:05.000 --> 00:26:06.000 But I want you to realize now 00:26:06.000 --> 00:26:07.000 that you see the separation? 00:26:08.000 --> 00:26:10.000 You have an endpoint identifier 00:26:10.000 --> 00:26:12.000 and that is totally different 00:26:13.000 --> 00:26:14.000 from where you're located. 00:26:15.000 --> 00:26:16.000 So what does that mean now? 00:26:16.000 --> 00:26:19.000 If you are 10.0.0.5, 00:26:20.000 --> 00:26:22.000 you are 10.0.0.5. 00:26:23.000 --> 00:26:25.000 You are 10.0.0.5 00:26:26.000 --> 00:26:30.000 currently connected to 192.168.1.1. 00:26:32.000 --> 00:26:34.000 You are 10.0.0.5 00:26:34.000 --> 00:26:36.000 currently connected to 192.168.1.1. 00:26:37.000 --> 00:26:38.000 Think about it, cell phone. 00:26:38.000 --> 00:26:40.000 You are currently 5.5.5, 00:26:40.000 --> 00:26:43.000 5.5.5, 5.5, 5.5 00:26:43.000 --> 00:26:46.000 connected to the Phoenix cell tower. 00:26:48.000 --> 00:26:49.000 You then hop in your car, 00:26:49.000 --> 00:26:50.000 drive to Vegas. 00:26:50.000 --> 00:26:53.000 You are 5.5.5, 5.5.5, 5.5, 5.5 00:26:53.000 --> 00:26:56.000 connected to the Vegas cell tower. 00:26:56.000 --> 00:26:57.000 Same idea. 00:26:57.000 --> 00:26:58.000 Same idea. 00:27:05.000 --> 00:27:06.000 This improves scalability 00:27:06.000 --> 00:27:08.000 for routing systems, as we've seen. 00:27:09.000 --> 00:27:11.000 Improves multi-homing efficiency. 00:27:13.000 --> 00:27:15.000 Makes it a lot easier to do your trust sec 00:27:15.000 --> 00:27:16.000 and your traffic engineering 00:27:16.000 --> 00:27:17.000 and all of that stuff 00:27:17.000 --> 00:27:18.000 when it's all said and done. 00:27:21.000 --> 00:27:22.000 Now you need to understand 00:27:22.000 --> 00:27:24.000 these terms for the exam as well. 00:27:25.000 --> 00:27:26.000 You need to understand, first of all, 00:27:26.000 --> 00:27:27.000 what an XTR is. 00:27:28.000 --> 00:27:31.000 XTR is any router, 00:27:32.000 --> 00:27:33.000 LISP router, 00:27:33.000 --> 00:27:36.000 LISP router that performs 00:27:36.000 --> 00:27:40.000 ITR and ETR functions. 00:27:42.000 --> 00:27:45.000 ITR is a LISP router 00:27:45.000 --> 00:27:49.000 that encapsulates IP packets 00:27:53.000 --> 00:27:55.000 that are leaving the environment. 00:27:56.000 --> 00:27:58.000 So if traffic is flowing this way, 00:27:59.000 --> 00:28:02.000 I am an ITR. 00:28:04.000 --> 00:28:07.000 If traffic's flowing this way, 00:28:07.000 --> 00:28:10.000 then I'm an ETR. 00:28:10.000 --> 00:28:12.000 ETR says a LISP router 00:28:12.000 --> 00:28:15.000 that decapsulates LISP packets 00:28:15.000 --> 00:28:19.000 from a site that are destined to that site. 00:28:20.000 --> 00:28:22.000 So packets leaving my site, 00:28:23.000 --> 00:28:24.000 I'm an ITR. 00:28:24.000 --> 00:28:26.000 For packets coming in, I'm an ETR. 00:28:29.000 --> 00:28:31.000 We perform ITR functions, 00:28:31.000 --> 00:28:32.000 encapsulation functions, 00:28:32.000 --> 00:28:34.000 and you perform ETR functions, 00:28:34.000 --> 00:28:36.000 decapsulation functions. 00:28:37.000 --> 00:28:39.000 So in this case here, 00:28:40.000 --> 00:28:43.000 we take a momentary step back. 00:28:44.000 --> 00:28:46.000 So this LISP router 00:28:46.000 --> 00:28:48.000 is going to be an ITR as traffic leaves 00:28:48.000 --> 00:28:50.000 and an ETR as traffic arrives. 00:28:50.000 --> 00:28:52.000 An ITR as traffic leaves, 00:28:52.000 --> 00:28:54.000 an ETR as traffic arrives. 00:28:54.000 --> 00:28:56.000 An ITR as traffic leaves, 00:28:56.000 --> 00:28:57.000 an ETR as traffic arrives. 00:28:57.000 --> 00:28:58.000 Remember that. 00:29:03.000 --> 00:29:05.000 Also, I want you to notice this. 00:29:05.000 --> 00:29:07.000 This is critical. 00:29:07.000 --> 00:29:10.000 The ETR, the ETR, not the ITR, 00:29:10.000 --> 00:29:11.000 the ETR, 00:29:11.000 --> 00:29:13.000 they might test you on this, 00:29:14.000 --> 00:29:17.000 publishes EID 00:29:17.000 --> 00:29:20.000 to RLOC mappings for a site. 00:29:20.000 --> 00:29:22.000 So the functionality of the ETR 00:29:22.000 --> 00:29:24.000 is to also do what? 00:29:24.000 --> 00:29:26.000 It's to learn 00:29:26.000 --> 00:29:29.000 who's connected to the router 00:29:29.000 --> 00:29:30.000 locally 00:29:30.000 --> 00:29:33.000 and then update 00:29:33.000 --> 00:29:36.000 the centralized server 00:29:36.000 --> 00:29:38.000 that has the database 00:29:38.000 --> 00:29:40.000 of information. 00:29:42.000 --> 00:29:44.000 So let's talk about that server. 00:29:44.000 --> 00:29:46.000 The server could actually be 00:29:46.000 --> 00:29:47.000 a physical server, folks, 00:29:47.000 --> 00:29:49.000 you have doing this job, 00:29:49.000 --> 00:29:51.000 or it could be another router. 00:29:51.000 --> 00:29:54.000 A router, you can have Cisco routers 00:29:54.000 --> 00:29:58.000 acting as a LISP mapping server. 00:30:00.000 --> 00:30:02.000 And so regardless of 00:30:02.000 --> 00:30:03.000 whether it's a physical server 00:30:03.000 --> 00:30:04.000 or a router, 00:30:04.000 --> 00:30:06.000 what is the mapping server all about? 00:30:06.000 --> 00:30:08.000 It's about having a database. 00:30:08.000 --> 00:30:10.000 And it is going to learn 00:30:10.000 --> 00:30:14.000 about all the endpoint identifiers 00:30:14.000 --> 00:30:16.000 and their prefixes. 00:30:16.000 --> 00:30:20.000 So you are 10.0.0.5 00:30:20.000 --> 00:30:22.000 slash whatever, right? 00:30:22.000 --> 00:30:24.000 All of that, we learn that. 00:30:24.000 --> 00:30:25.000 And what? 00:30:25.000 --> 00:30:27.000 Who you're connected to. 00:30:27.000 --> 00:30:29.000 So I take, like, say, 00:30:29.000 --> 00:30:30.000 this information as an example 00:30:30.000 --> 00:30:32.000 and this information 00:30:32.000 --> 00:30:34.000 on the ETR. 00:30:34.000 --> 00:30:35.000 So I take that 00:30:35.000 --> 00:30:37.000 and I send that up to here. 00:30:37.000 --> 00:30:39.000 That's what I'm going to go ahead and do. 00:30:41.000 --> 00:30:43.000 And then a mapping server 00:30:43.000 --> 00:30:45.000 stores all of that information for us. 00:30:47.000 --> 00:30:50.000 So if we go back to this page again, 00:30:50.000 --> 00:30:53.000 who could that be in this environment? 00:30:53.000 --> 00:30:55.000 Well, typically, right, 00:30:55.000 --> 00:30:56.000 we could, 00:30:56.000 --> 00:30:57.000 not typically, 00:30:57.000 --> 00:30:59.000 we could have it as a server over here. 00:31:02.000 --> 00:31:04.000 Or we could even set up 00:31:04.000 --> 00:31:05.000 this device right here. 00:31:05.000 --> 00:31:06.000 That could be a mapping server 00:31:06.000 --> 00:31:07.000 if we wanted to. 00:31:10.000 --> 00:31:11.000 And therefore, 00:31:11.000 --> 00:31:13.000 this device would have the database 00:31:13.000 --> 00:31:15.000 of RLOC to user mappings. 00:31:15.000 --> 00:31:17.000 RLOC to user mappings. 00:31:17.000 --> 00:31:18.000 Now, let me take a moment here 00:31:18.000 --> 00:31:20.000 to explain to you that 00:31:22.000 --> 00:31:23.000 there's the concept 00:31:23.000 --> 00:31:26.000 of what we call the home site. 00:31:26.000 --> 00:31:27.000 So, for example, 00:31:27.000 --> 00:31:28.000 if this network here, 00:31:28.000 --> 00:31:29.000 this entire site, 00:31:29.000 --> 00:31:33.000 was 10.0.0.0 size 24, 00:31:33.000 --> 00:31:36.000 and you are in your home site, 00:31:36.000 --> 00:31:37.000 you are 10.0.0.5 00:31:37.000 --> 00:31:40.000 and you are in 10.0.0.24, 00:31:40.000 --> 00:31:41.000 then this mapping server 00:31:41.000 --> 00:31:43.000 does not have to be updated 00:31:43.000 --> 00:31:45.000 about you specifically. 00:31:46.000 --> 00:31:47.000 Why? 00:31:47.000 --> 00:31:50.000 Because you are in your home site. 00:31:50.000 --> 00:31:53.000 So, if everybody's in their home site, 00:31:53.000 --> 00:31:54.000 then the mapping server 00:31:54.000 --> 00:31:56.000 will really only have 00:31:56.000 --> 00:32:00.000 network IDs to RLOC mappings. 00:32:00.000 --> 00:32:01.000 That's it. 00:32:01.000 --> 00:32:03.000 So, like 10.0.0 size 24 is connected here. 00:32:03.000 --> 00:32:06.000 10.0.1.0 size 24 is connected here. 00:32:06.000 --> 00:32:07.000 Okay? 00:32:07.000 --> 00:32:08.000 But if you move, 00:32:08.000 --> 00:32:09.000 like, for example, 00:32:09.000 --> 00:32:11.000 if I move from here 00:32:11.000 --> 00:32:13.000 all the way down to here, 00:32:13.000 --> 00:32:15.000 then I'm in a different site. 00:32:16.000 --> 00:32:17.000 Therefore, 00:32:17.000 --> 00:32:19.000 this device would then update 00:32:19.000 --> 00:32:20.000 the mapping server 00:32:20.000 --> 00:32:24.000 and say 10.0.0.5 00:32:24.000 --> 00:32:27.000 slash 32, 00:32:27.000 --> 00:32:29.000 making it like a host-type route, 00:32:29.000 --> 00:32:30.000 is connected to, 00:32:30.000 --> 00:32:35.000 let's say this RLOC is 192.168.255. 00:32:35.000 --> 00:32:36.000 Or what were we doing? 00:32:36.000 --> 00:32:37.000 Ones? 00:32:37.000 --> 00:32:39.000 1.3. 00:32:39.000 --> 00:32:41.000 You are now connected 00:32:41.000 --> 00:32:45.000 to 192.168.1.3. 00:32:45.000 --> 00:32:47.000 So, that would be a specific entry. 00:32:47.000 --> 00:32:49.000 So, specific entries are only sent 00:32:49.000 --> 00:32:53.000 when you're not in your home site. 00:32:53.000 --> 00:32:54.000 But if you're in your home site, 00:32:54.000 --> 00:32:56.000 but if you're not in your home site, 00:32:56.000 --> 00:32:57.000 we'll send that. 00:32:57.000 --> 00:32:58.000 So, to wrap that up, 00:32:58.000 --> 00:32:59.000 keep that in mind, 00:32:59.000 --> 00:33:00.000 that you don't have to worry about 00:33:00.000 --> 00:33:02.000 this becoming overwhelmed 00:33:02.000 --> 00:33:05.000 unless everybody's not in their home site. 00:33:05.000 --> 00:33:06.000 But if the majority of people 00:33:06.000 --> 00:33:07.000 are in their home site, 00:33:07.000 --> 00:33:09.000 then that's perfectly fine, right? 00:33:09.000 --> 00:33:10.000 Because anybody who moves, 00:33:10.000 --> 00:33:12.000 it'll be updated for those specific moves, 00:33:12.000 --> 00:33:15.000 but the home sites stay where they are. 00:33:15.000 --> 00:33:16.000 And so, the home site would be listed, 00:33:16.000 --> 00:33:17.000 like I said, as a slash 24, 00:33:17.000 --> 00:33:20.000 or whatever the subnet mask is. 00:33:20.000 --> 00:33:21.000 And if you're not in your home site, 00:33:21.000 --> 00:33:22.000 you're a slash 32, 00:33:22.000 --> 00:33:24.000 which means from a routing standpoint, 00:33:24.000 --> 00:33:26.000 longest match rule wins. 00:33:26.000 --> 00:33:28.000 Longest match rule wins by the mapping server, 00:33:28.000 --> 00:33:35.000 just like it would for a routing protocol. 00:33:35.000 --> 00:33:36.000 All right, where were we? 00:33:36.000 --> 00:33:37.000 We were on the mapping server, right? 00:33:37.000 --> 00:33:39.000 Okay, so we're on the mapping server. 00:33:39.000 --> 00:33:40.000 So, know that. 00:33:40.000 --> 00:33:43.000 Now, the mapping server, 00:33:43.000 --> 00:33:45.000 there's another entity, sorry, 00:33:45.000 --> 00:33:47.000 called the map resolver. 00:33:47.000 --> 00:33:48.000 And the map resolver is the one 00:33:48.000 --> 00:33:51.000 who actually does the work. 00:33:51.000 --> 00:33:53.000 It resolves the mapping request. 00:33:53.000 --> 00:33:54.000 So, for example, 00:33:54.000 --> 00:33:59.000 if I am trying to go from here over to here, 00:33:59.000 --> 00:34:03.000 how do I know that this device lives there? 00:34:03.000 --> 00:34:04.000 Well, that's not up to this person to decide. 00:34:04.000 --> 00:34:05.000 That doesn't matter. 00:34:05.000 --> 00:34:07.000 They don't need to know that. 00:34:07.000 --> 00:34:08.000 They just need to know the IP address 00:34:08.000 --> 00:34:10.000 that they're trying to reach. 00:34:10.000 --> 00:34:12.000 So, I'm trying to reach 10.0.0.10, 00:34:12.000 --> 00:34:14.000 or 10.0.10.10, I should say. 00:34:14.000 --> 00:34:17.000 So, my packet, I create a source for me, 00:34:17.000 --> 00:34:18.000 destination to there. 00:34:18.000 --> 00:34:20.000 So, when the packet arrives at this router, 00:34:20.000 --> 00:34:21.000 this router has to figure out, 00:34:21.000 --> 00:34:23.000 how do I get to 10.0.10.10? 00:34:23.000 --> 00:34:26.000 So, it has to reach out, 00:34:26.000 --> 00:34:27.000 not to the mapping server, 00:34:27.000 --> 00:34:29.000 no, no, no, to the map resolver. 00:34:29.000 --> 00:34:31.000 So, it reaches out to the map resolver 00:34:31.000 --> 00:34:32.000 to find out, and it says, 00:34:32.000 --> 00:34:34.000 hey, hey, woo-woo, yeah, map resolver. 00:34:34.000 --> 00:34:35.000 Look at me. 00:34:35.000 --> 00:34:37.000 I'm the ITR over here, 00:34:37.000 --> 00:34:38.000 and I want to know, 00:34:38.000 --> 00:34:43.000 how in the world do I get to 10.0.10.10? 00:34:43.000 --> 00:34:45.000 And so, then the map resolver 00:34:45.000 --> 00:34:48.000 contacts the mapping server, 00:34:48.000 --> 00:34:49.000 and then that information 00:34:49.000 --> 00:34:51.000 can be provided back as an example. 00:34:51.000 --> 00:34:53.000 So, what would be provided back is, 00:34:53.000 --> 00:34:56.000 this is reachable via this. 00:34:56.000 --> 00:34:59.000 So, now I know that if I want to go here, 00:34:59.000 --> 00:35:01.000 I got to go to here first. 00:35:01.000 --> 00:35:02.000 So, what this does is, 00:35:02.000 --> 00:35:03.000 it allows this router to know, 00:35:03.000 --> 00:35:06.000 it now has to encapsulate the packet 00:35:06.000 --> 00:35:09.000 from here over to here, 00:35:09.000 --> 00:35:11.000 and then this router decapsulates it 00:35:11.000 --> 00:35:12.000 and sends it to here. 00:35:12.000 --> 00:35:14.000 So, essentially, when I'm routing, 00:35:14.000 --> 00:35:16.000 I'm not routing from here 00:35:16.000 --> 00:35:17.000 all the way over to here. 00:35:17.000 --> 00:35:18.000 I'm routing just like we did 00:35:18.000 --> 00:35:21.000 with GRE tunnels and IPSec tunnels. 00:35:21.000 --> 00:35:23.000 I'm routing from here over to here, 00:35:23.000 --> 00:35:26.000 boof, because we're separating, right? 00:35:26.000 --> 00:35:28.000 And then if you decide to move somewhere, 00:35:28.000 --> 00:35:29.000 if you move, let's say this device 00:35:29.000 --> 00:35:32.000 moves over here into a different lift site, 00:35:32.000 --> 00:35:34.000 then that mapping server would be updated. 00:35:34.000 --> 00:35:37.000 So, when you ask for that information, 00:35:37.000 --> 00:35:39.000 then you're going to be pointed that way instead, 00:35:39.000 --> 00:35:41.000 so you can build your tunnels that way. 00:35:41.000 --> 00:35:43.000 It's all about building tunnels. 00:35:43.000 --> 00:35:45.000 So, the mapping server and map resolver 00:35:45.000 --> 00:35:47.000 can be two different devices, 00:35:47.000 --> 00:35:50.000 or they can be one in the same device, folks. 00:35:50.000 --> 00:35:52.000 And typically, for the sake of software-defined access, 00:35:52.000 --> 00:35:55.000 they're typically going to be one in the same device. 00:35:55.000 --> 00:35:58.000 But in like a really large internet LISP implementation, 00:35:58.000 --> 00:36:00.000 they're typically going to be different devices 00:36:00.000 --> 00:36:01.000 when it's all said and done, 00:36:01.000 --> 00:36:03.000 so the mapping server doesn't get overwhelmed 00:36:03.000 --> 00:36:06.000 with requests plus all the updates 00:36:06.000 --> 00:36:08.000 that it needs to keep track of. 00:36:12.000 --> 00:36:14.000 Yeah, there are a lot of similarities 00:36:14.000 --> 00:36:16.000 with SD-WAN and different things like that. 00:36:16.000 --> 00:36:17.000 Why? Because when you think about it, 00:36:17.000 --> 00:36:19.000 it's all about software-defined networking. 00:36:19.000 --> 00:36:20.000 So, taking those concepts 00:36:20.000 --> 00:36:22.000 and applying them in those different scenarios, 00:36:22.000 --> 00:36:24.000 absolutely. 00:36:24.000 --> 00:36:26.000 Are any of these servers the DNA center? 00:36:26.000 --> 00:36:28.000 The DNA center, we're going to get to that. 00:36:28.000 --> 00:36:29.000 We're going to get to that. 00:36:29.000 --> 00:36:31.000 We're getting there. 00:36:31.000 --> 00:36:33.000 We're getting there. 00:36:33.000 --> 00:36:36.000 All right, so with that said now, 00:36:36.000 --> 00:36:38.000 let's talk about or look at an example 00:36:38.000 --> 00:36:40.000 of what's going on in this particular case. 00:36:41.000 --> 00:36:46.000 So, we have to talk about registration now. 00:36:46.000 --> 00:36:49.000 So, right now, we're going to go with, 00:36:49.000 --> 00:36:52.000 this could be the internet as an example, right? 00:36:52.000 --> 00:36:55.000 Or, look, it says you're at the core of your network. 00:36:55.000 --> 00:36:58.000 So, if you think of this as a multi-layer switch, 00:36:58.000 --> 00:37:00.000 this is a multi-layer switch instead, 00:37:00.000 --> 00:37:04.000 and you think of this as like one of your core switches, right? 00:37:04.000 --> 00:37:06.000 It's the same thing we were just talking about. 00:37:06.000 --> 00:37:08.000 It's the same thing. 00:37:08.000 --> 00:37:10.000 We just have routers here instead of multi-layer switches. 00:37:10.000 --> 00:37:12.000 And so, this is a multi-layer switch, 00:37:12.000 --> 00:37:13.000 and this is our subnet. 00:37:13.000 --> 00:37:14.000 This is a multi-layer switch. 00:37:14.000 --> 00:37:16.000 This is our subnet with our end users attached to it. 00:37:21.000 --> 00:37:24.000 So, now, ETRs, remember, 00:37:24.000 --> 00:37:27.000 send the mappings to the mapping server. 00:37:27.000 --> 00:37:32.000 So, the ETR sends the mappings to the mapping server. 00:37:32.000 --> 00:37:34.000 So, let me diagram this out for you. 00:37:34.000 --> 00:37:36.000 What do we have? 00:37:36.000 --> 00:37:42.000 We have this ETR saying that 10.0.10.10.32 00:37:42.000 --> 00:37:46.000 is connected to this RLOC. 00:37:46.000 --> 00:37:50.000 And then this ETR is saying 10.0.20.20.32 00:37:50.000 --> 00:37:52.000 is connected to this RLOC. 00:37:52.000 --> 00:37:53.000 And then they send them to who? 00:37:53.000 --> 00:37:56.000 They send them to the mapping server. 00:37:56.000 --> 00:37:57.000 All right, so remember that for the exam. 00:37:57.000 --> 00:38:01.000 The ETR, the ETR is the one that updates the mapping server. 00:38:01.000 --> 00:38:04.000 Now, remember, if these were all in their home networks, 00:38:04.000 --> 00:38:09.000 then we would be seeing things like this instead. 00:38:09.000 --> 00:38:11.000 All right, so if they're in their home networks, 00:38:11.000 --> 00:38:13.000 this is what we would see. 00:38:13.000 --> 00:38:14.000 If you're not in your home networks, 00:38:14.000 --> 00:38:18.000 then you're going to get some individual entries that are added, 00:38:18.000 --> 00:38:19.000 slash 32s. 00:38:19.000 --> 00:38:24.000 So, now we have our mapping server database as an example. 00:38:24.000 --> 00:38:30.000 So, we enter the database, or the info in our database, 00:38:30.000 --> 00:38:33.000 and the mapping server sends a map notify to the ETR 00:38:33.000 --> 00:38:36.000 to confirm that the map register has been received and processed. 00:38:36.000 --> 00:38:39.000 Perfect. 00:38:39.000 --> 00:38:40.000 All right, now what about forwarding now? 00:38:40.000 --> 00:38:43.000 Let's diagram forwarding so you can have a better understanding. 00:38:43.000 --> 00:38:46.000 So, in this case, in a LISP environment, 00:38:46.000 --> 00:38:48.000 purely LISP environment, right, with underlying, 00:38:48.000 --> 00:38:50.000 let's say we're running ISIS underneath all of this, 00:38:50.000 --> 00:38:51.000 what's going to happen? 00:38:51.000 --> 00:38:54.000 Well, let's say this user wants to talk to this user over here. 00:38:54.000 --> 00:38:56.000 So, what does that user do on the left-hand side? 00:38:56.000 --> 00:38:58.000 They create a packet. 00:38:58.000 --> 00:38:59.000 And what is that packet? 00:38:59.000 --> 00:39:06.000 That packet says, I want to go from me, which is 10.0.10.10 to 10.0.20.20. 00:39:06.000 --> 00:39:08.000 Now, how would I figure out the destination? 00:39:08.000 --> 00:39:09.000 Well, DNS, folks. 00:39:09.000 --> 00:39:10.000 That doesn't change, right? 00:39:10.000 --> 00:39:13.000 You're still using DNS for name resolution. 00:39:13.000 --> 00:39:16.000 Everything else you know still exists here. 00:39:16.000 --> 00:39:17.000 And it works, okay? 00:39:17.000 --> 00:39:18.000 It works. 00:39:18.000 --> 00:39:21.000 So, your user still has an IP address, a subnet, everything, 00:39:21.000 --> 00:39:25.000 DNS configuration, default gateway configuration, like you know it. 00:39:25.000 --> 00:39:30.000 And if you type in a browser URL or you're browsing network neighborhood 00:39:30.000 --> 00:39:32.000 or you type in the name of the PC you want to contact 00:39:32.000 --> 00:39:33.000 or the server you want to contact, 00:39:33.000 --> 00:39:36.000 DNS is going to resolve the IP address of that. 00:39:36.000 --> 00:39:37.000 So, there you go. 00:39:37.000 --> 00:39:38.000 We got our information. 00:39:38.000 --> 00:39:39.000 None of that changes. 00:39:39.000 --> 00:39:40.000 That's still the same. 00:39:40.000 --> 00:39:42.000 But here's now, and then we send it out. 00:39:42.000 --> 00:39:43.000 And where does it go? 00:39:43.000 --> 00:39:45.000 It goes to your default gateway, right? 00:39:45.000 --> 00:39:46.000 We have our frame. 00:39:46.000 --> 00:39:47.000 We build our frame. 00:39:47.000 --> 00:39:48.000 The frame goes to your default gateway. 00:39:48.000 --> 00:39:50.000 Okay, now your default gateway has it in this case. 00:39:50.000 --> 00:39:54.000 And so, your default gateway is the LISP router in our SD access environment. 00:39:54.000 --> 00:39:58.000 It's the default gateway, the LISP router in the SD access environment. 00:39:58.000 --> 00:40:02.000 So, now this router has to say, how in the world do I get here? 00:40:02.000 --> 00:40:04.000 How in the world do I get here? 00:40:04.000 --> 00:40:06.000 Because it doesn't know how to get there. 00:40:06.000 --> 00:40:09.000 Remember, it does not learn about those networks. 00:40:09.000 --> 00:40:10.000 Through what? 00:40:10.000 --> 00:40:13.000 Through OSPF or through ISIS or through EIGRP. 00:40:13.000 --> 00:40:15.000 Remember what I said. 00:40:15.000 --> 00:40:19.000 You don't learn about the destination networks through your dynamic routing protocols anymore. 00:40:19.000 --> 00:40:20.000 You don't. 00:40:20.000 --> 00:40:22.000 So, you don't know how to get there. 00:40:22.000 --> 00:40:23.000 You don't. 00:40:23.000 --> 00:40:25.000 But what you do have is you have a LISP forwarding table. 00:40:25.000 --> 00:40:27.000 So, you look at your LISP forwarding table. 00:40:27.000 --> 00:40:29.000 And in this case, it's empty. 00:40:29.000 --> 00:40:30.000 Aw, too bad, right? 00:40:30.000 --> 00:40:31.000 Well, what are we going to do? 00:40:31.000 --> 00:40:34.000 As a router, I'm going to park the packet. 00:40:34.000 --> 00:40:36.000 So, let's park the packet. 00:40:36.000 --> 00:40:37.000 Hoeing on to it. 00:40:37.000 --> 00:40:42.000 And now we're going to send out a LISP message to the mapping resolver. 00:40:42.000 --> 00:40:47.000 Hey, who is 10.0.20.20? 00:40:47.000 --> 00:40:52.000 And I'm going to then put my transport layer information on it, which is UDP. 00:40:52.000 --> 00:40:55.000 And then we're going to put the source IP, which is what? 00:40:55.000 --> 00:40:57.000 Me. 00:40:57.000 --> 00:41:01.000 And the destination IP is the IP address of that mapping resolver, which I don't have on here. 00:41:01.000 --> 00:41:03.000 So, I just put RLOC of map resolver. 00:41:03.000 --> 00:41:07.000 So, whatever its IP address is, that ETR would have to be trained about that. 00:41:07.000 --> 00:41:09.000 So, it would be part of their configuration. 00:41:09.000 --> 00:41:12.000 So, let's go ahead now and send it to the map resolver. 00:41:12.000 --> 00:41:14.000 The map resolver gets it. 00:41:14.000 --> 00:41:15.000 And what does it do? 00:41:15.000 --> 00:41:18.000 It's going to contact the mapping server. 00:41:18.000 --> 00:41:20.000 In this case, it's one and the same device. 00:41:20.000 --> 00:41:26.000 So, the mapping server consults its database, and it says this is reachable via that. 00:41:26.000 --> 00:41:33.000 So, now that information can be provided to that ETR or the ITR that had asked for it. 00:41:33.000 --> 00:41:38.000 So, that information is then created into a packet and sent back. 00:41:38.000 --> 00:41:43.000 So, you'll see here that it says the endpoint to RLOC mapping is 10.0.20.20 size 32. 00:41:43.000 --> 00:41:48.000 It's via 192.0.2.62. 00:41:48.000 --> 00:41:51.000 So, now what can we do in this particular case? 00:41:51.000 --> 00:41:57.000 We can take that information, put it in our cache, our LISP cache. 00:41:57.000 --> 00:42:00.000 And now we can go ahead and encapsulate. 00:42:00.000 --> 00:42:03.000 So, that way there we can go from here to here. 00:42:03.000 --> 00:42:04.000 So, think about it. 00:42:04.000 --> 00:42:07.000 Just like with GRE, just like with IPsec, what did we do? 00:42:07.000 --> 00:42:09.000 We added onto the header to encapsulate. 00:42:09.000 --> 00:42:12.000 So, just like with GRE, what's the source? 00:42:12.000 --> 00:42:16.000 In this case, the source is going to be 203.0.1.13.87. 00:42:16.000 --> 00:42:17.000 What's our destination? 00:42:17.000 --> 00:42:19.000 192.0.2.62. 00:42:19.000 --> 00:42:21.000 And can we get to each other? 00:42:21.000 --> 00:42:24.000 Of course we can because those addresses are part of OSPF. 00:42:24.000 --> 00:42:26.000 Those addresses are part of EIGRP. 00:42:26.000 --> 00:42:30.000 Those addresses are part of ISIS. 00:42:30.000 --> 00:42:32.000 So, we can route to each other. 00:42:32.000 --> 00:42:35.000 I just don't know about everything behind, right? 00:42:35.000 --> 00:42:36.000 I don't know about everything in every LISP site. 00:42:36.000 --> 00:42:37.000 I learned about it how? 00:42:37.000 --> 00:42:40.000 With LISP mappings. 00:42:40.000 --> 00:42:42.000 So, now let's go ahead and build that frame. 00:42:42.000 --> 00:42:44.000 Let's do the encapsulation. 00:42:44.000 --> 00:42:48.000 So, we're going to add on our LISP header. 00:42:48.000 --> 00:42:49.000 And that's going to include what? 00:42:49.000 --> 00:42:56.000 It's going to include information like the LISP header itself, 00:42:56.000 --> 00:42:59.000 then the UDP information for transportation, 00:42:59.000 --> 00:43:03.000 and then the source and destination IP address. 00:43:03.000 --> 00:43:05.000 Notice source is this, destination is this. 00:43:06.000 --> 00:43:08.000 So, I can send it across the network. 00:43:08.000 --> 00:43:11.000 So, you know, going through all of this stuff, folks, 00:43:11.000 --> 00:43:15.000 if we go back to this page here, think about it now. 00:43:15.000 --> 00:43:17.000 What information would this be? 00:43:17.000 --> 00:43:19.000 Let me clean this up just a bit. 00:43:19.000 --> 00:43:21.000 That would be the information of this. 00:43:21.000 --> 00:43:27.000 How do I go from here, let's say, over to here? 00:43:27.000 --> 00:43:29.000 Those are the two values. 00:43:29.000 --> 00:43:31.000 That is the source. 00:43:31.000 --> 00:43:34.000 That is the destination. 00:43:35.000 --> 00:43:36.000 The users aren't the source. 00:43:36.000 --> 00:43:38.000 The users aren't the destination. 00:43:38.000 --> 00:43:39.000 You're the source. 00:43:39.000 --> 00:43:41.000 You're the destination. 00:43:41.000 --> 00:43:45.000 Do I even know about that network and who lives there? 00:43:45.000 --> 00:43:50.000 No, I don't, because that network is not advertised in OSPF, EIG, or PRIS, but you are. 00:43:50.000 --> 00:43:51.000 You are. 00:43:51.000 --> 00:43:53.000 As a LISP router, I know about you. 00:43:53.000 --> 00:43:54.000 I know about you. 00:43:54.000 --> 00:43:55.000 I know about you. 00:43:55.000 --> 00:43:56.000 I know about you. 00:43:56.000 --> 00:43:57.000 I know about you. 00:43:57.000 --> 00:43:59.000 Do the LISP routers even know about these devices? 00:43:59.000 --> 00:44:00.000 No, they don't. 00:44:00.000 --> 00:44:02.000 They don't have to, right? 00:44:02.000 --> 00:44:06.000 All I need to know, like BGP, there's me, there's you. 00:44:06.000 --> 00:44:09.000 If the rest of the network is working, I can get to you. 00:44:09.000 --> 00:44:10.000 That's all that matters. 00:44:10.000 --> 00:44:11.000 Do I have to know about the rest of the network? 00:44:11.000 --> 00:44:12.000 No, I don't. 00:44:12.000 --> 00:44:15.000 I don't care about the rest of the network. 00:44:15.000 --> 00:44:17.000 OSPF cares about it. 00:44:17.000 --> 00:44:18.000 EIGRP cares about it. 00:44:18.000 --> 00:44:21.000 ISIS cares about it, but from a LISP standpoint, I don't know. 00:44:21.000 --> 00:44:22.000 LISP knows about this. 00:44:22.000 --> 00:44:25.000 LISP knows about that, and that, and that, and that. 00:44:25.000 --> 00:44:27.000 LISP doesn't know about anything else. 00:44:27.000 --> 00:44:31.000 OSPF knows about all the stuff in here, ISIS or EIGRP, but again, doesn't know about any 00:44:31.000 --> 00:44:33.000 of that stuff either outside. 00:44:33.000 --> 00:44:35.000 Who knows about this outside stuff? 00:44:35.000 --> 00:44:40.000 Well, you, as a LISP router, only knows about your local stuff, but the mapping server knows 00:44:40.000 --> 00:44:41.000 about everything else. 00:44:41.000 --> 00:44:42.000 Ah, there you go. 00:44:42.000 --> 00:44:45.000 You see how it's all coming together now? 00:44:45.000 --> 00:44:46.000 I know, it's a mind trip. 00:44:46.000 --> 00:44:49.000 It really is. 00:44:49.000 --> 00:44:52.000 So, now that we have it encapsulated, we send it. 00:44:52.000 --> 00:44:53.000 Yay, away we go. 00:44:53.000 --> 00:44:54.000 Woo-hoo. 00:44:54.000 --> 00:44:56.000 Look at all that. 00:44:56.000 --> 00:44:59.000 Guess we've got to have our MTU set properly, don't we? 00:44:59.000 --> 00:45:04.000 One of the great things about setting up a LISP environment is that it's recommended 00:45:04.000 --> 00:45:07.000 that you use what we call jumble frames and jumble packets. 00:45:07.000 --> 00:45:12.000 So, having the ability to transport MTU sizes of like 9,000 folks, 9,000. 00:45:12.000 --> 00:45:13.000 I'm serious. 00:45:13.000 --> 00:45:14.000 Right? 00:45:14.000 --> 00:45:20.000 So, modern day Ethernet interfaces on devices that would support LISP and SD access and 00:45:20.000 --> 00:45:26.000 stuff like that, right, we could set our MTUs to 9,000 inside of our environment, and therefore 00:45:26.000 --> 00:45:30.000 we could support these bigger packets without having to do any type of fragmentation or 00:45:30.000 --> 00:45:32.000 anything on the user's end. 00:45:32.000 --> 00:45:36.000 So, we could send 1,500 bytes packets as a user, encapsulate it all, and it would get 00:45:36.000 --> 00:45:41.000 to the other side without a problem. 00:45:41.000 --> 00:45:43.000 But that only works inside of your environment. 00:45:43.000 --> 00:45:46.000 If you decide to leave your environment and go to the Internet, well, that's going to 00:45:46.000 --> 00:45:47.000 cause problems, obviously. 00:45:47.000 --> 00:45:53.000 So, you know, there's considerations that have to be taken into effect when you're using 00:45:53.000 --> 00:46:00.000 MTU because the Internet uses 1,500. 00:46:00.000 --> 00:46:03.000 So, now when it gets to this side, this router is what right now? 00:46:03.000 --> 00:46:05.000 It's the ETR right now. 00:46:05.000 --> 00:46:06.000 It's receiving. 00:46:06.000 --> 00:46:07.000 So, now it has to decapsulate. 00:46:07.000 --> 00:46:11.000 And then it reads this and goes, oh, okay, I'll send that to you at this particular interface. 00:46:11.000 --> 00:46:14.000 And we're good to go. 00:46:14.000 --> 00:46:16.000 Fun stuff, isn't it? 00:46:16.000 --> 00:46:17.000 All right. 00:46:17.000 --> 00:46:18.000 All right. 00:46:18.000 --> 00:46:23.000 So, now let's think about this situation in this scenario. 00:46:23.000 --> 00:46:26.000 We go back to here. 00:46:26.000 --> 00:46:32.000 What about everything that's going on over here? 00:46:32.000 --> 00:46:35.000 What about everything that's going on over here right now? 00:46:35.000 --> 00:46:36.000 Okay. 00:46:36.000 --> 00:46:44.000 We call these areas non-LISP sites, non-LISP sites. 00:46:44.000 --> 00:46:45.000 That's what they are. 00:46:46.000 --> 00:46:51.000 So, you can think of the Internet as a non-LISP site when you are looking at it from the perspective 00:46:51.000 --> 00:46:53.000 of SD-Access. 00:46:53.000 --> 00:46:57.000 You can look at your data center as a non-LISP site because over there we're doing other things. 00:46:57.000 --> 00:46:59.000 We're doing ACI instead. 00:46:59.000 --> 00:47:07.000 And so, we have LISP and everything running in here for our enterprise environment, SD-Access. 00:47:07.000 --> 00:47:10.000 You got SD-WAN at the edge of your environment. 00:47:10.000 --> 00:47:12.000 You got your Internet connections at the edge of your environment. 00:47:12.000 --> 00:47:13.000 Right? 00:47:13.000 --> 00:47:14.000 So, you got different places. 00:47:14.000 --> 00:47:19.000 So, anything that's not part of that SD-Access fabric where you have LISP set up, right, 00:47:19.000 --> 00:47:22.000 those are non-LISP sites. 00:47:22.000 --> 00:47:32.000 So, we still need to ensure that those non-LISP sites are identified and handled appropriately. 00:47:32.000 --> 00:47:39.000 So, here's an example of a non-LISP site. 00:47:39.000 --> 00:47:40.000 We can pretend that's the data center. 00:47:40.000 --> 00:47:41.000 We can pretend that's the Internet. 00:47:41.000 --> 00:47:43.000 It doesn't matter. 00:47:43.000 --> 00:47:50.000 But the idea is how do we deal with traffic coming like this or like this? 00:47:50.000 --> 00:47:55.000 We need information here that's going to allow that to happen. 00:47:55.000 --> 00:48:03.000 So, does that mean if this is the Internet, for example, that we would need a mapping here for 0000 00:48:03.000 --> 00:48:10.000 slash 0 via the RLOC address of a router here? 00:48:10.000 --> 00:48:11.000 Sure. 00:48:11.000 --> 00:48:15.000 Yeah. 00:48:15.000 --> 00:48:20.000 So, that way, if we're trying to go to the Internet, we're trying to go to a place like that, right, 00:48:20.000 --> 00:48:27.000 if that's the best way to go, we need that information. 00:48:27.000 --> 00:48:29.000 So, we need a router sitting there. 00:48:29.000 --> 00:48:30.000 And what do we call that router? 00:48:30.000 --> 00:48:33.000 We call it a Peter and a Piter. 00:48:33.000 --> 00:48:35.000 Again, I don't make up these names. 00:48:35.000 --> 00:48:37.000 I just teach you about them. 00:48:37.000 --> 00:48:38.000 Peters and Piters. 00:48:38.000 --> 00:48:44.000 Peter, Piter, picked a pickle. 00:48:44.000 --> 00:48:50.000 So, we've got a proxy ETR and a proxy ITR. 00:48:50.000 --> 00:49:00.000 So, for the exam, remember, ETR, ITR, routers that connect your LISP sites to other LISP routers. 00:49:00.000 --> 00:49:01.000 Okay. 00:49:01.000 --> 00:49:02.000 So, LISP site. 00:49:02.000 --> 00:49:03.000 LISP site. 00:49:03.000 --> 00:49:04.000 ETR, ITR. 00:49:05.000 --> 00:49:10.000 Non-LISP site is Peter and Piter, proxy ETRs and proxy ITRs. 00:49:10.000 --> 00:49:12.000 ETRs and ITRs. 00:49:12.000 --> 00:49:17.000 Proxy ETRs and proxy ITRs. 00:49:17.000 --> 00:49:26.000 So, now, if I'm trying to go, for example, to the data center or the Internet, this would be my ITR, 00:49:26.000 --> 00:49:31.000 and now this is my P-E-T-R. 00:49:31.000 --> 00:49:39.000 But if the traffic's going this way, then this is my P-I-T-R and my E-T-R. 00:49:39.000 --> 00:49:40.000 Know that for the exam. 00:49:40.000 --> 00:49:44.000 Be able to identify that in any diagrams they provide you. 00:49:44.000 --> 00:49:47.000 So, the Peter receives traffic from LISP sites, right? 00:49:47.000 --> 00:49:59.000 The Peter receives traffic from LISP sites, and the Piter sends traffic to LISP sites in this example. 00:50:01.000 --> 00:50:06.000 All right. 00:50:06.000 --> 00:50:19.000 So, make sure you know EID, RLOC, ITR, ETR, MS, MR, Peter, Piter, LISP site, non-LISP site, 00:50:19.000 --> 00:50:21.000 terms and definitions for the certification exam. 00:50:21.000 --> 00:50:34.000 If you know those, you'll get all the questions right. 00:50:34.000 --> 00:50:37.000 So, that is LISP. 00:50:37.000 --> 00:50:40.000 As you need to know it for the exam. 00:50:40.000 --> 00:50:47.000 And remember, it might be still a little confusing, but I'm going to show you it in SD-AXIS here momentarily. 00:50:47.000 --> 00:50:51.000 But before we get to that, let's talk about VXLAN. 00:50:51.000 --> 00:51:05.000 So, VXLAN is a technology that allows us to create tunnels from one point to another point. 00:51:05.000 --> 00:51:11.000 Now, pause right there, because this, what I just said, causes confusion with LISP. 00:51:11.000 --> 00:51:14.000 Because isn't that what we just did with LISP? 00:51:14.000 --> 00:51:17.000 The answer to that is yes. 00:51:17.000 --> 00:51:24.000 What I want you to understand is that LISP is both a control plane protocol, and we saw that, right, 00:51:24.000 --> 00:51:31.000 learning about who's who, updating the mapping server, using the mapping resolver, right, 00:51:31.000 --> 00:51:33.000 figuring out how to go from point A to point B. 00:51:33.000 --> 00:51:36.000 That is control plane. 00:51:36.000 --> 00:51:41.000 LISP is also data plane, meaning that it can do the encapsulation. 00:51:41.000 --> 00:51:48.000 And I showed you the encapsulation when we went through our example like this. 00:51:48.000 --> 00:51:50.000 So, it can do both. 00:51:50.000 --> 00:51:53.000 It can do both control plane and data plane. 00:51:53.000 --> 00:52:04.000 But what you need to understand is that LISP as a data plane protocol for SD-AXIS doesn't work. 00:52:04.000 --> 00:52:10.000 LISP as a control plane protocol for SD-AXIS works. 00:52:10.000 --> 00:52:19.000 So, we use LISP for the control plane in SD-AXIS, but we don't use LISP for encapsulation. 00:52:19.000 --> 00:52:21.000 That's right, we don't. 00:52:21.000 --> 00:52:25.000 So, we use LISP for the database. 00:52:25.000 --> 00:52:28.000 We use LISP for the RLOCs. 00:52:28.000 --> 00:52:30.000 We use LISP for that stuff. 00:52:31.000 --> 00:52:35.000 But we use VXLAN for the encapsulation. 00:52:35.000 --> 00:52:39.000 And you might be saying, why, Raymond, why? 00:52:39.000 --> 00:52:43.000 Well, I'll tell you why in a moment after you learn a little bit about VXLAN. 00:52:43.000 --> 00:52:52.000 So, VXLAN allows us to build and extend a Layer 2 network over a Layer 3 network. 00:52:52.000 --> 00:52:53.000 That's your answer. 00:52:53.000 --> 00:52:54.000 That's the answer you're looking for. 00:52:54.000 --> 00:52:55.000 Why, Raymond? 00:52:56.000 --> 00:53:04.000 LISP lets you build a Layer 3 network over a Layer 3 network. 00:53:04.000 --> 00:53:06.000 That's what LISP does. 00:53:06.000 --> 00:53:09.000 Layer 3 over Layer 3. 00:53:09.000 --> 00:53:16.000 So, when I was tunneling, I was tunneling Layer 3 traffic over Layer 3 with LISP. 00:53:16.000 --> 00:53:23.000 But now with VXLAN, I can tunnel Layer 2 traffic from end to end. 00:53:24.000 --> 00:53:26.000 Why is that important? 00:53:26.000 --> 00:53:34.000 Well, if I am in VLAN 10 here, and my IP address is this, and this is our site. 00:53:34.000 --> 00:53:37.000 Okay, so this is our site for VLAN 10. 00:53:37.000 --> 00:53:41.000 And you are here, and you are 10.0.0.10. 00:53:41.000 --> 00:53:44.000 And you right now are not in your home site. 00:53:44.000 --> 00:53:46.000 You are not in your home site. 00:53:46.000 --> 00:53:49.000 How in the world do I talk directly to you? 00:53:49.000 --> 00:53:51.000 We are in the same subnet. 00:53:51.000 --> 00:53:53.000 We are in the same VLAN. 00:53:53.000 --> 00:53:55.000 We are in the same broadcast domain. 00:53:55.000 --> 00:54:02.000 But right now, we are separated by this giant Layer 3 network. 00:54:02.000 --> 00:54:04.000 How do I broadcast to you? 00:54:04.000 --> 00:54:06.000 How do I send a frame to you? 00:54:06.000 --> 00:54:09.000 I can't using LISP. 00:54:09.000 --> 00:54:12.000 But I can using VXLAN. 00:54:12.000 --> 00:54:20.000 Because VXLAN will create a Layer 2 tunnel over that Layer 3 network. 00:54:20.000 --> 00:54:24.000 All while preserving the Layer 2 header information. 00:54:24.000 --> 00:54:25.000 That's right. 00:54:25.000 --> 00:54:33.000 So when this PC builds the frame, the entire frame is preserved. 00:54:33.000 --> 00:54:37.000 Whereas with LISP, the frame is destroyed. 00:54:37.000 --> 00:54:38.000 Let me repeat that. 00:54:38.000 --> 00:54:44.000 With VXLAN, the PC's frame is preserved. 00:54:44.000 --> 00:54:48.000 With LISP, the PC's frame is destroyed. 00:54:48.000 --> 00:54:52.000 So if I can preserve the frame of the PC, 00:54:52.000 --> 00:54:55.000 then I could send that frame over to here. 00:54:55.000 --> 00:54:58.000 And you would actually get the frame. 00:55:01.000 --> 00:55:03.000 So yeah, Layer 2 anywhere. 00:55:05.000 --> 00:55:13.000 That's why this SDAccess solution with TrustSec and all of that stuff works. 00:55:13.000 --> 00:55:15.000 Because of this. 00:55:19.000 --> 00:55:23.000 Building tunnels. 00:55:23.000 --> 00:55:27.000 Remember, tunnels means encapsulation. 00:55:27.000 --> 00:55:31.000 So VXLAN is what we call an overlay technology. 00:55:31.000 --> 00:55:32.000 You know that for the exam. 00:55:32.000 --> 00:55:38.000 An overlay technology that allows us to preserve that Layer 2 header information. 00:55:38.000 --> 00:55:42.000 So we use VXLAN for the data plane in SDAccess. 00:55:42.000 --> 00:55:46.000 We use LISP for the control plane for SDAccess. 00:55:46.000 --> 00:55:49.000 Remember, we're covering these from the perspective of SDAccess 00:55:49.000 --> 00:55:52.000 to get you ready for the exam. 00:55:52.000 --> 00:55:53.000 There's a lot more to these, though, 00:55:53.000 --> 00:55:58.000 because VXLAN was originally introduced to solve problems in our data centers. 00:55:58.000 --> 00:56:00.000 And what was the problem with our data centers? 00:56:00.000 --> 00:56:03.000 They're getting too big. 00:56:03.000 --> 00:56:09.000 And then how is somebody like AWS or Azure or Google Cloud going to support 00:56:09.000 --> 00:56:15.000 the billions and billions of servers they have running 00:56:15.000 --> 00:56:19.000 and put them wherever they want but still have them in the same subnet, 00:56:19.000 --> 00:56:22.000 still have them within the same VLAN? 00:56:22.000 --> 00:56:25.000 So if you think about the architecture here, 00:56:25.000 --> 00:56:32.000 with VXLAN in my data center, I have my Layer 2, Layer 3 boundary here. 00:56:32.000 --> 00:56:36.000 So all the servers are connected to their default gateways. 00:56:36.000 --> 00:56:40.000 Notice that my server has the ability to support virtual machines 00:56:40.000 --> 00:56:43.000 in any one of those subnets, any one of those VLANs. 00:56:43.000 --> 00:56:48.000 But look, every server can do it. 00:56:48.000 --> 00:56:49.000 So what's the problem now? 00:56:49.000 --> 00:56:58.000 Well, if traffic from VLAN 10 wants to go to this VLAN 10, there is no problem. 00:56:58.000 --> 00:57:01.000 Why? Why? 00:57:01.000 --> 00:57:05.000 Well, because if that's a trunk link and that's a trunk link, 00:57:05.000 --> 00:57:08.000 traffic comes in the trunk link, goes out the trunk link, 00:57:08.000 --> 00:57:10.000 no problem in the same VLAN. 00:57:10.000 --> 00:57:14.000 There's no issue there because we're connected to the same switch. 00:57:14.000 --> 00:57:26.000 But what's the problem if I want to go from here over to here? 00:57:26.000 --> 00:57:29.000 What's the problem there? 00:57:29.000 --> 00:57:31.000 This Layer 3 environment, right? 00:57:31.000 --> 00:57:37.000 This Layer 3 environment is not going to preserve the what? 00:57:37.000 --> 00:57:42.000 The frame header of VLAN 10 that is needed by this server, 00:57:42.000 --> 00:57:45.000 this virtual machine as the receiver. 00:57:45.000 --> 00:57:47.000 It's not preserved. 00:57:47.000 --> 00:57:48.000 This wouldn't work. 00:57:48.000 --> 00:57:50.000 So you implement VXLAN. 00:57:50.000 --> 00:57:53.000 And now what you do is you have this is called a VTEP. 00:57:53.000 --> 00:57:54.000 This is called a VTEP. 00:57:54.000 --> 00:58:00.000 This is called a VTEP. 00:58:00.000 --> 00:58:03.000 Virtual Tunnel Endpoint, that's all that means. 00:58:03.000 --> 00:58:08.000 And now we tunnel, so we encapsulate from here. 00:58:08.000 --> 00:58:12.000 We encapsulate, so that way there I can send the traffic 00:58:12.000 --> 00:58:16.000 and preserve all that Layer 2 header information, 00:58:16.000 --> 00:58:20.000 decapsulate here, and then now you get the frame 00:58:20.000 --> 00:58:24.000 exactly as that device sent it. 00:58:24.000 --> 00:58:25.000 Adding what? 00:58:25.000 --> 00:58:26.000 Giving you what? 00:58:26.000 --> 00:58:33.000 Flexibility, control, expansion, scalability, 00:58:33.000 --> 00:58:40.000 scalability to the tune of 16 million possible VLANs with VXLAN 00:58:40.000 --> 00:58:46.000 as opposed to 4,000 approximately with VLANs. 00:58:46.000 --> 00:58:48.000 Think about it as a service provider. 00:58:48.000 --> 00:58:50.000 That's awesome. 00:58:50.000 --> 00:58:53.000 Somebody who runs a massive data center, AWS, Azure, 00:58:53.000 --> 00:58:57.000 this is what makes it work. 00:58:57.000 --> 00:58:59.000 And so now we have what are called VNIs, 00:58:59.000 --> 00:59:03.000 which are just your VXLAN number identifier. 00:59:03.000 --> 00:59:10.000 So when we used to call it VLAN number, well, these are called VNIs. 00:59:10.000 --> 00:59:13.000 Very elastic, right, because we've got Layer 2 adjacencies 00:59:13.000 --> 00:59:14.000 across a router boundary. 00:59:14.000 --> 00:59:17.000 So I can, from here to here, we can be in the same subnet VLAN 00:59:17.000 --> 00:59:21.000 broadcast domain, no problem, across a Layer 3 network. 00:59:22.000 --> 00:59:26.000 Also now, when you create your tunnel from here to here, 00:59:26.000 --> 00:59:29.000 don't forget that your routing protocol, 00:59:29.000 --> 00:59:34.000 your underlying routing protocol can take advantage of load balancing. 00:59:34.000 --> 00:59:37.000 So I can go, I can send some traffic this way, some traffic this way, 00:59:37.000 --> 00:59:39.000 some this way, some this way, some this way, some this way, 00:59:39.000 --> 00:59:42.000 some this way, some this way, some this way, some this way, 00:59:42.000 --> 00:59:46.000 some this way, until it eventually all reaches down to the other side. 00:59:46.000 --> 00:59:47.000 Maximizing what? 00:59:47.000 --> 00:59:51.000 Maximizing the bandwidth and transportation over the network. 00:59:57.000 --> 01:00:03.000 So for VXLAN, I might be VLAN 10 here, sales. 01:00:03.000 --> 01:00:04.000 VLAN 10 here, sales. 01:00:04.000 --> 01:00:10.000 So let's say I'm .5 and you're .6. 01:00:10.000 --> 01:00:11.000 No problem. 01:00:11.000 --> 01:00:13.000 We need to talk to each other. 01:00:13.000 --> 01:00:14.000 We have our tunnel. 01:00:14.000 --> 01:00:18.000 It's called MAC in IP slash UDP tunneling. 01:00:18.000 --> 01:00:22.000 So the VTAP is used to what? 01:00:22.000 --> 01:00:24.000 Encapsulate and decapsulate. 01:00:24.000 --> 01:00:29.000 The VTAP is used to encapsulate and decapsulate. 01:00:29.000 --> 01:00:30.000 Wait a second. 01:00:30.000 --> 01:00:33.000 Are we running LISP at the exact same time here, folks? 01:00:33.000 --> 01:00:35.000 Yes, we are. 01:00:35.000 --> 01:00:38.000 So that is also running LISP. 01:00:38.000 --> 01:00:42.000 So in this case, LISP, what's this called right now? 01:00:42.000 --> 01:00:47.000 What's that called if the traffic's going this way? 01:00:47.000 --> 01:00:49.000 Do you remember? 01:00:49.000 --> 01:00:52.000 You got to know this for the exam. 01:00:52.000 --> 01:00:53.000 That's right. 01:00:53.000 --> 01:00:55.000 It's the ITR. 01:00:55.000 --> 01:00:57.000 Exactly, the ITR. 01:00:57.000 --> 01:00:59.000 And what about over here? 01:00:59.000 --> 01:01:04.000 If the traffic's flowing this way, you are the ETR. 01:01:04.000 --> 01:01:05.000 There you go. 01:01:06.000 --> 01:01:14.000 Right, so the VTAP in VXLAN is the same as the LISP ITR in ETR. 01:01:25.000 --> 01:01:28.000 Oh, but you're going to hate me in a moment, folks. 01:01:28.000 --> 01:01:30.000 Well, a little bit longer than a moment, 01:01:30.000 --> 01:01:32.000 because we'll take a break. 01:01:32.000 --> 01:01:35.000 There's also another name for this. 01:01:35.000 --> 01:01:37.000 Three different names. 01:01:37.000 --> 01:01:42.000 Oh, I hate technology sometimes. 01:01:42.000 --> 01:01:44.000 We'll come back to that. 01:01:44.000 --> 01:01:45.000 But I do want you to remember, 01:01:45.000 --> 01:01:49.000 the VTAP is used to encapsulate and decapsulate traffic in VXLAN. 01:01:49.000 --> 01:01:53.000 The ITR and the ETR are used to encapsulate and decapsulate in what? 01:01:53.000 --> 01:01:54.000 LISP. 01:01:54.000 --> 01:01:55.000 Keep that in mind. 01:01:55.000 --> 01:01:57.000 Got to keep these separated for the exam. 01:01:58.000 --> 01:02:00.000 That's how you win or lose on this exam, right? 01:02:00.000 --> 01:02:02.000 By knowing these things. 01:02:07.000 --> 01:02:09.000 So what is happening here? 01:02:09.000 --> 01:02:10.000 So let me show you the difference. 01:02:10.000 --> 01:02:11.000 Let's go to LISP. 01:02:11.000 --> 01:02:13.000 This is going to help you visualize what's going on here. 01:02:13.000 --> 01:02:21.000 So with LISP, I want you to realize that if this was my original information, 01:02:21.000 --> 01:02:26.000 then that would all be this right here. 01:02:26.000 --> 01:02:27.000 This is the same. 01:02:27.000 --> 01:02:29.000 Okay, that's the same. 01:02:29.000 --> 01:02:33.000 So if that was my original information and I was using LISP, 01:02:33.000 --> 01:02:36.000 notice how my Ethernet header is gone. 01:02:36.000 --> 01:02:37.000 You see that? 01:02:37.000 --> 01:02:38.000 It's gone. 01:02:38.000 --> 01:02:39.000 So that is gone. 01:02:39.000 --> 01:02:42.000 So in reality, I've got to draw my line like this. 01:02:42.000 --> 01:02:43.000 There we go. 01:02:43.000 --> 01:02:45.000 That's what it is. 01:02:45.000 --> 01:02:50.000 So the Ethernet header is for LISP or going from router to router. 01:02:50.000 --> 01:02:58.000 So that header there is not preserving the PC's original Ethernet information. 01:02:58.000 --> 01:03:02.000 Okay, that's why we don't use LISP in the data plane for SD access. 01:03:02.000 --> 01:03:07.000 Because with VXLAN, you'll see my original header is preserved. 01:03:07.000 --> 01:03:09.000 Then I put on my VXLAN header. 01:03:09.000 --> 01:03:12.000 Then I put on a UDP header, a new IDP header, 01:03:12.000 --> 01:03:15.000 and then the Ethernet header to go from device to device, 01:03:15.000 --> 01:03:17.000 and then a new header from device to device, device, device, device, right? 01:03:18.000 --> 01:03:21.000 So this is the one that's going to change as we hop from router to router to router to router to router, 01:03:21.000 --> 01:03:23.000 like we do in normal routing. 01:03:23.000 --> 01:03:25.000 And this is going to be what? 01:03:25.000 --> 01:03:31.000 That is the IP address of my LISP RLOC. 01:03:31.000 --> 01:03:43.000 That's my LISP RLOC source and destination, which is the VTEP source and destination. 01:03:43.000 --> 01:03:46.000 That's why on the last page I said, right, that's your LISP, 01:03:46.000 --> 01:03:48.000 I-T-R, E-T-R, VTEP. 01:03:48.000 --> 01:03:54.000 So the RLOC address is going to be dumped into there for VXLAN, 01:03:54.000 --> 01:03:59.000 source and destination of tunnel, source and destination of tunnel, 01:03:59.000 --> 01:04:05.000 while preserving the original IP of the PC and the original Ethernet information from that PC. 01:04:05.000 --> 01:04:06.000 It's great stuff. 01:04:06.000 --> 01:04:08.000 It's all virtualization, and that's the hardest part. 01:04:08.000 --> 01:04:11.000 If you're struggling with it, wrapping your head around it, because it's all virtualization, right? 01:04:11.000 --> 01:04:14.000 We have our underlying network running OSPF, EIGRP, IISIS. 01:04:14.000 --> 01:04:16.000 That doesn't change. 01:04:16.000 --> 01:04:20.000 But now we are doing virtualization on top of that, and only some routers are running this, right? 01:04:20.000 --> 01:04:23.000 Like we said, none of these are running LISP in here. 01:04:23.000 --> 01:04:26.000 Only the ones on the edge of this environment are running LISP. 01:04:26.000 --> 01:04:30.000 The VTEPs are only on the edge of the environment, right? 01:04:30.000 --> 01:04:32.000 But it just works because what are we doing? 01:04:32.000 --> 01:04:39.000 Encapsulating from end-to-end, end-to-end, end-to-end to make it all work. 01:04:40.000 --> 01:04:44.000 So VXLAN only defines the data plane. 01:04:44.000 --> 01:04:46.000 Always, always, always. 01:04:46.000 --> 01:04:51.000 Meaning VXLAN, folks, is not a control plane protocol at all. 01:04:51.000 --> 01:04:52.000 So LISP can be both. 01:04:52.000 --> 01:04:56.000 Like I said, LISP can be both a control plane protocol and a data plane protocol. 01:04:56.000 --> 01:04:58.000 There's no denying that. 01:04:58.000 --> 01:05:08.000 But VXLAN is only a data plane protocol and is used to encapsulate and forward that traffic to the environment. 01:05:08.000 --> 01:05:10.000 If it doesn't have a control plane protocol, it doesn't work. 01:05:10.000 --> 01:05:12.000 So in this case, we are using what? 01:05:12.000 --> 01:05:16.000 LISP as the control plane protocol. 01:05:16.000 --> 01:05:23.000 But in your data center, you might be using multi-protocol BGP. 01:05:23.000 --> 01:05:32.000 AWS or Azure might be using multi-protocol BGP. 01:05:32.000 --> 01:05:35.000 You could even do static unicast, but that's not a scalable option. 01:05:35.000 --> 01:05:37.000 But you can totally do it if you want to. 01:05:37.000 --> 01:05:43.000 Statically define the endpoints of your tunnels instead of using BGP or LISP. 01:05:43.000 --> 01:05:50.000 And then you can even do multicast if you want to. 01:05:50.000 --> 01:05:56.000 So I've verified all my notes, and I've got you all prepared for the certification exam right now. 01:05:56.000 --> 01:06:02.000 However, it's going to require you to go back and make sure you understand those terms and you understand the definitions. 01:06:02.000 --> 01:06:13.000 I encourage you to take it a little bit further and try to build a map in your mind of the networks, of the diagrams I've given you that explain how everything goes. 01:06:13.000 --> 01:06:14.000 What's what? 01:06:14.000 --> 01:06:23.000 Because on the exam, if you can picture in your head a picture, any picture I provided to you, and then automatically when you see a term, go, oh, that would be there. 01:06:23.000 --> 01:06:24.000 That would be there. 01:06:24.000 --> 01:06:25.000 That would be there. 01:06:25.000 --> 01:06:26.000 That was this. 01:06:26.000 --> 01:06:27.000 That was this. 01:06:27.000 --> 01:06:28.000 That was, oh, VXLAN. 01:06:28.000 --> 01:06:29.000 That would be a tunnel from there to there. 01:06:29.000 --> 01:06:30.000 That's only the data plane. 01:06:31.000 --> 01:06:33.000 That is how you're going to get through this exam. 01:06:33.000 --> 01:06:37.000 And if you prepare properly, folks, you'll get all the questions right. 01:06:37.000 --> 01:06:42.000 They are not hard questions if you just simply understand the fundamentals that I've given you here. 01:06:42.000 --> 01:06:45.000 You don't have to go any deeper than that. 01:06:45.000 --> 01:06:54.000 But seeing it holistically as a whole, as well as the individual terms, is how you're going to ace these questions on the exam about LISP and VXLAN.