WEBVTT 00:00:01.000 --> 00:00:08.000 All right, so now we are going to have a discussion on configuring and verifying VLANs to get us ready for the certification exam. 00:00:08.000 --> 00:00:13.000 The thing about the certification exam is it doesn't actually say we have to know anything about VLANs. 00:00:13.000 --> 00:00:17.000 And I'm just going to double check that in case it's been updated within the last couple of minutes. 00:00:17.000 --> 00:00:20.000 But I don't think it has. 00:00:20.000 --> 00:00:28.000 But if we go under our infrastructure, no, it just says trunking protocols, Ether channels, spanning tree protocol. 00:00:28.000 --> 00:00:30.000 But, folks, here's the deal. 00:00:30.000 --> 00:00:34.000 You are going to be tested on VLANs because VLANs are all part of Layer 2. 00:00:34.000 --> 00:00:37.000 It doesn't make sense to have trunks if you don't have VLANs. 00:00:37.000 --> 00:00:45.000 So I'm assuming that they omitted VLANs and they're just assuming you're going to know about VLANs because you're talking about 802.1Q trunking protocols. 00:00:45.000 --> 00:00:46.000 All right. 00:00:46.000 --> 00:00:54.000 And in reality, 802.1Q trunking protocols is really just 802.1Q trunking protocol. 00:00:54.000 --> 00:00:56.000 It's all said and done. 00:00:56.000 --> 00:00:59.000 But with that said, we need to know VLANs. 00:00:59.000 --> 00:01:01.000 We need to know 802.1Q. 00:01:01.000 --> 00:01:08.000 And so we'll start off with a VLAN discussion, and then we'll have a trunking discussion after this to put it all together. 00:01:08.000 --> 00:01:11.000 So how many of you have VLANs? 00:01:11.000 --> 00:01:16.000 And if you have a VLAN, type in the number of VLANs that you have. 00:01:16.000 --> 00:01:23.000 So if you have a VLAN, type in the number of VLANs that you have in your environment. 00:01:23.000 --> 00:01:24.000 Lots. 00:01:24.000 --> 00:01:25.000 It's a good answer. 00:01:25.000 --> 00:01:26.000 I like that answer. 00:01:26.000 --> 00:01:27.000 Hundreds. 00:01:27.000 --> 00:01:28.000 Sixty. 00:01:28.000 --> 00:01:29.000 Eight hundred. 00:01:29.000 --> 00:01:30.000 A thousand. 00:01:30.000 --> 00:01:31.000 Too many. 00:01:31.000 --> 00:01:32.000 Many. 00:01:32.000 --> 00:01:33.000 Yes. 00:01:33.000 --> 00:01:34.000 All right. 00:01:34.000 --> 00:01:45.000 So let me try to put this in a way that makes it really to understand why we have VLANs. 00:01:46.000 --> 00:01:57.000 So if we had a router like this, and off of that router we put a switch. 00:01:57.000 --> 00:02:02.000 Let's say it's a 48-port switch. 00:02:02.000 --> 00:02:07.000 Then we would have many users connected to this one switch. 00:02:07.000 --> 00:02:11.000 Let's say, for example, we have some people from HR. 00:02:11.000 --> 00:02:15.000 Let's say, for example, we have some people from sales. 00:02:15.000 --> 00:02:18.000 Let's say, for example, we have some people from support. 00:02:18.000 --> 00:02:21.000 Let's say, for example, we have people from IT. 00:02:21.000 --> 00:02:29.000 Let's say, for example, we have guests. 00:02:29.000 --> 00:02:32.000 What's the problem with that, folks? 00:02:32.000 --> 00:02:33.000 What's the problem with that? 00:02:33.000 --> 00:02:47.000 Okay. 00:02:47.000 --> 00:02:51.000 So first of all, that's a security problem. 00:02:51.000 --> 00:02:54.000 That is absolutely a security problem. 00:02:54.000 --> 00:02:57.000 Why is it a security problem? 00:02:57.000 --> 00:03:02.000 Because everyone on the switch right now is in the same subnet. 00:03:02.000 --> 00:03:04.000 They're in the same VLAN. 00:03:04.000 --> 00:03:07.000 They're in the same broadcast domain. 00:03:07.000 --> 00:03:11.000 Do we ever really want traffic from different departments, folks, 00:03:11.000 --> 00:03:16.000 intermingling with each other in the exact same subnet size, VLAN size, broadcast domain? 00:03:16.000 --> 00:03:17.000 Not in modern-day networks. 00:03:17.000 --> 00:03:18.000 Why? 00:03:18.000 --> 00:03:20.000 Because of security. 00:03:20.000 --> 00:03:28.000 If anybody in HR or anybody in finance sent out a, let's say, a broadcast frame, 00:03:28.000 --> 00:03:31.000 everybody would get a copy of that. 00:03:31.000 --> 00:03:33.000 So we absolutely don't want that from a security perspective. 00:03:33.000 --> 00:03:35.000 So what is the other option we have? 00:03:35.000 --> 00:03:41.000 The other option we would have would be to set up our environment, so 1, 2, 3, 4, 5, 6. 00:03:41.000 --> 00:03:44.000 So 1, 2, 3, 4, 5, 6. 00:03:44.000 --> 00:03:45.000 Put a switch. 00:03:45.000 --> 00:03:46.000 Put a switch. 00:03:46.000 --> 00:03:47.000 Put a switch. 00:03:47.000 --> 00:03:48.000 Put a switch. 00:03:48.000 --> 00:03:49.000 Put a switch. 00:03:49.000 --> 00:03:50.000 Put a switch. 00:03:50.000 --> 00:03:51.000 All right. 00:03:51.000 --> 00:03:53.000 We'll say this is the rest of the network. 00:03:53.000 --> 00:03:54.000 All right. 00:03:54.000 --> 00:03:55.000 Put a little cloud there. 00:03:55.000 --> 00:03:59.000 And now we have all of our HR people here. 00:03:59.000 --> 00:04:00.000 We have all of our guests here. 00:04:00.000 --> 00:04:02.000 We have all of our finance people here. 00:04:02.000 --> 00:04:04.000 We have all of our IT people connected here. 00:04:04.000 --> 00:04:05.000 We have all our support people here. 00:04:05.000 --> 00:04:07.000 We have all of our sales people here. 00:04:07.000 --> 00:04:12.000 Now is this way better from a security standpoint than this? 00:04:12.000 --> 00:04:13.000 Yes or no? 00:04:14.000 --> 00:04:15.000 Absolutely. 00:04:15.000 --> 00:04:16.000 Yes, it is. 00:04:16.000 --> 00:04:17.000 Yes, it is. 00:04:17.000 --> 00:04:19.000 Because what do we have the ability to do here? 00:04:19.000 --> 00:04:21.000 Specify our security boundaries. 00:04:21.000 --> 00:04:22.000 Security boundaries. 00:04:22.000 --> 00:04:23.000 Security boundaries. 00:04:23.000 --> 00:04:24.000 Security boundaries. 00:04:24.000 --> 00:04:25.000 Security boundaries. 00:04:25.000 --> 00:04:26.000 Security boundaries. 00:04:26.000 --> 00:04:27.000 Security boundaries. 00:04:27.000 --> 00:04:28.000 Okay? 00:04:28.000 --> 00:04:32.000 And as a result of that, better security, number one. 00:04:32.000 --> 00:04:37.000 We can control the flow of traffic a lot better. 00:04:37.000 --> 00:04:39.000 Problem with this, it's very wasteful. 00:04:39.000 --> 00:04:40.000 It's very expensive. 00:04:40.000 --> 00:04:43.000 When you think about the fact that in finance, you might only have one. 00:04:43.000 --> 00:04:44.000 Let me ask you this. 00:04:44.000 --> 00:04:46.000 How many people in your finance department, folks? 00:04:46.000 --> 00:04:48.000 How many people in your finance department? 00:04:48.000 --> 00:04:50.000 Most of you are going to give me a low number. 00:04:50.000 --> 00:04:53.000 Some of you may give me a high number. 00:04:53.000 --> 00:04:55.000 It really depends on what your organization is. 00:04:55.000 --> 00:04:57.000 Yeah, so what do you say? 00:04:57.000 --> 00:04:59.000 Let's go with four people, let's say, for fun today. 00:04:59.000 --> 00:05:00.000 Okay. 00:05:00.000 --> 00:05:01.000 Conrad, you got about 100. 00:05:01.000 --> 00:05:02.000 All right. 00:05:02.000 --> 00:05:03.000 More in your case. 00:05:03.000 --> 00:05:04.000 All right. 00:05:04.000 --> 00:05:05.000 How many HR people? 00:05:05.000 --> 00:05:06.000 Again, really depends. 00:05:07.000 --> 00:05:08.000 Okay. 00:05:08.000 --> 00:05:09.000 But let's say 10 HR people. 00:05:09.000 --> 00:05:10.000 Sales, let's say sales has 30. 00:05:10.000 --> 00:05:11.000 Support has nine. 00:05:11.000 --> 00:05:12.000 IT has, oh, like we always have just one person, right, in IT. 00:05:12.000 --> 00:05:13.000 Feels like that, doesn't it? 00:05:13.000 --> 00:05:14.000 But how many ports on all these switches? 00:05:14.000 --> 00:05:15.000 Right? 00:05:15.000 --> 00:05:16.000 48. 00:05:16.000 --> 00:05:17.000 How much money do we spend on all these switches? 00:05:17.000 --> 00:05:18.000 A lot of money. 00:05:18.000 --> 00:05:19.000 Now, you could say, well, we'll just buy a switch with, like, 12 ports or 24. 00:05:19.000 --> 00:05:20.000 It doesn't matter. 00:05:20.000 --> 00:05:21.000 The fact of the matter is you've got all these switches. 00:05:21.000 --> 00:05:22.000 You've got all these ports. 00:05:22.000 --> 00:05:23.000 You've got all these switches. 00:05:23.000 --> 00:05:24.000 You've got all these ports. 00:05:24.000 --> 00:05:25.000 You've got all these ports. 00:05:25.000 --> 00:05:26.000 You've got all these ports. 00:05:26.000 --> 00:05:27.000 You've got all these ports. 00:05:27.000 --> 00:05:28.000 You've got all these ports. 00:05:28.000 --> 00:05:29.000 You've got all these ports. 00:05:30.000 --> 00:05:47.059 So, VLANs allow me to do this exact same thing but over here. 00:05:47.059 --> 00:05:53.000 What if instead we said you are in your own VLAN? 00:05:53.000 --> 00:05:55.000 Let's call it VLAN 10. 00:05:55.000 --> 00:05:57.000 You are in your own VLAN. 00:05:57.000 --> 00:05:58.000 We'll call it VLAN 20. 00:05:58.000 --> 00:06:00.000 You are in your own VLAN. 00:06:00.000 --> 00:06:01.000 VLAN 30. 00:06:01.000 --> 00:06:03.000 You are in your own VLAN. 00:06:03.000 --> 00:06:04.000 VLAN 40. 00:06:04.000 --> 00:06:05.000 VLAN 50. 00:06:05.000 --> 00:06:11.000 VLAN 60. 00:06:11.000 --> 00:06:23.000 Can each of these VLANs talk directly to each other folks through this switch? 00:06:23.000 --> 00:06:24.000 No, right? 00:06:24.000 --> 00:06:26.000 We would have to do what? 00:06:26.000 --> 00:06:30.000 We would have to do routing and typically when we route, 00:06:30.000 --> 00:06:35.000 we also have our security boundaries and policies in place. 00:06:35.000 --> 00:06:38.000 Now, we would allow all the traffic across this trunk link. 00:06:38.000 --> 00:06:40.000 So, that would be a trunk link. 00:06:40.000 --> 00:06:43.000 But if somebody in finance needed to talk to somebody in sales, 00:06:43.000 --> 00:06:45.000 the traffic would have to flow from here to the router, 00:06:45.000 --> 00:06:48.000 get routed back in down to sales. 00:06:48.000 --> 00:06:54.000 But the thing is is that that would be traffic that has to go that way. 00:06:55.000 --> 00:07:00.000 But if sales just sent out a broadcast, would any other environment get it? 00:07:00.000 --> 00:07:01.000 Would any other VLAN get it? 00:07:01.000 --> 00:07:02.000 Would it? 00:07:02.000 --> 00:07:03.000 No, they would. 00:07:03.000 --> 00:07:05.000 Only the devices in sales would get that. 00:07:05.000 --> 00:07:08.000 So, now we have the isolation we need. 00:07:08.000 --> 00:07:10.000 We have the security we need. 00:07:10.000 --> 00:07:12.000 We have the segmentation we need. 00:07:12.000 --> 00:07:17.000 We have the isolation we need. 00:07:17.000 --> 00:07:19.000 I already used the word isolation. 00:07:19.000 --> 00:07:21.000 I'm running out of words to use here. 00:07:21.000 --> 00:07:25.000 But the point of the matter is is that now it's not going to cost us as much. 00:07:25.000 --> 00:07:28.000 We still get away with the same situation. 00:07:28.000 --> 00:07:30.000 But now we've carved it up. 00:07:30.000 --> 00:07:35.000 So, we get better network performance as well because we're taking maybe large 00:07:35.000 --> 00:07:38.000 broadcast domains, making them smaller. 00:07:38.000 --> 00:07:43.000 We're getting better security because traffic within a VLAN stays in a VLAN. 00:07:43.000 --> 00:07:46.000 Just think about the rule of Vegas. 00:07:46.000 --> 00:07:48.000 What happens in Vegas stays in Vegas. 00:07:48.000 --> 00:07:52.000 Well, what happens in a VLAN stays in a VLAN unless you route it. 00:07:52.000 --> 00:07:56.000 So, what happens in Vegas stays in Vegas unless you route it. 00:07:56.000 --> 00:07:57.000 Same idea. 00:07:57.000 --> 00:08:00.000 So, that's what VLANs are going to give us the ability to do. 00:08:00.000 --> 00:08:02.000 So, now I get to maximize my budget. 00:08:02.000 --> 00:08:04.000 I get to, you know, ensure I'm not wasting money. 00:08:04.000 --> 00:08:07.000 And I get to ensure that we have the security that we need. 00:08:07.000 --> 00:08:12.000 So, I could really just fill every single port on a switch, have different people 00:08:12.000 --> 00:08:16.000 in different VLANs, but still have the isolation and security I need. 00:08:17.000 --> 00:08:20.000 So, what is a VLAN? 00:08:20.000 --> 00:08:25.000 A VLAN is a virtual LAN, folks, a virtual local area network. 00:08:25.000 --> 00:08:28.000 A VLAN, therefore, is a subnet. 00:08:28.000 --> 00:08:30.000 And we know a subnet is a broadcast domain. 00:08:30.000 --> 00:08:33.000 So, therefore, a VLAN is a broadcast domain. 00:08:33.000 --> 00:08:39.000 So, from a fundamental standpoint, each VLAN is its own subnet. 00:08:39.000 --> 00:08:41.000 Each VLAN is its own subnet. 00:08:41.000 --> 00:08:43.000 That's the fundamental rule of VLANs. 00:08:43.000 --> 00:08:45.000 Now, there's an exception to that rule. 00:08:45.000 --> 00:08:48.000 How many of you have ever worked with private VLANs? 00:08:48.000 --> 00:09:05.000 Okay, private VLANs is a way that we can take a single VLAN or, sorry, a single subnet 00:09:05.000 --> 00:09:07.000 and break that subnet up into multiple VLANs. 00:09:07.000 --> 00:09:09.000 We could do that with a private VLAN. 00:09:09.000 --> 00:09:11.000 I've got a fly flying around in here. 00:09:11.000 --> 00:09:13.000 It's really starting to bug me. 00:09:13.000 --> 00:09:14.000 It's almost hit me twice. 00:09:14.000 --> 00:09:17.000 I don't know if you saw it on camera, but it came close twice. 00:09:17.000 --> 00:09:21.000 Going to have to get it at the next break. 00:09:21.000 --> 00:09:22.000 All right. 00:09:22.000 --> 00:09:28.000 So, when it comes to our discussion here, we're not going to worry about private VLANs 00:09:28.000 --> 00:09:32.000 where you could have a multitude of different VLANs, different ISODs, different things like that, okay? 00:09:32.000 --> 00:09:37.000 But in the grand scheme of things, with a certification exam where private VLANs is not on the certification exam, 00:09:37.000 --> 00:09:41.000 if they ever ask you anything about a VLAN, it's a one-to-one relationship here. 00:09:41.000 --> 00:09:43.000 One VLAN equals one subnet. 00:09:43.000 --> 00:09:45.000 Therefore, every VLAN is its own broadcast domain. 00:09:45.000 --> 00:09:47.000 Every VLAN is its own subnet. 00:09:47.000 --> 00:09:48.000 Keep that in mind. 00:09:51.000 --> 00:09:55.000 So, let's do a little bit of review here when it comes to our switches. 00:09:55.000 --> 00:09:58.000 What does a switch do first, folks, when it receives a frame? 00:09:58.000 --> 00:10:00.000 Does anybody remember this from their CCNA days? 00:10:00.000 --> 00:10:04.000 What does a switch do first when it receives a frame? 00:10:12.000 --> 00:10:14.000 What does it have to do? 00:10:14.000 --> 00:10:16.000 Anybody remember? 00:10:16.000 --> 00:10:17.000 Okay. 00:10:17.000 --> 00:10:18.000 It has to learn. 00:10:18.000 --> 00:10:19.000 No, it has to learn. 00:10:19.000 --> 00:10:20.000 Yeah. 00:10:20.000 --> 00:10:21.000 That's right. 00:10:21.000 --> 00:10:28.000 It has to learn the source MAC address of the frame, populate the MAC address table with the what? 00:10:28.000 --> 00:10:34.000 The MAC address, the port the frame arrived in on, and the VLAN ID of the port. 00:10:34.000 --> 00:10:38.000 So, right now, you can see in our environment, let's just focus on this device here. 00:10:38.000 --> 00:10:47.000 This is PC1 in our topology right now, and you'll see that off of gig 101, we have this MAC address, and it was this VLAN. 00:10:47.000 --> 00:10:48.000 Why is it that VLAN? 00:10:48.000 --> 00:10:52.000 Because that's what our default configuration is on our switch. 00:10:52.000 --> 00:10:54.000 This switch right now is a default configuration. 00:10:54.000 --> 00:10:57.000 So, every port is part of VLAN 1 by default. 00:10:57.000 --> 00:11:05.000 So, right now, we have a device with that MAC address of gig 101, and it is part of VLAN number 1. 00:11:05.000 --> 00:11:07.000 So, that would be this PC right here. 00:11:07.000 --> 00:11:10.000 So, we learn that information, how? 00:11:10.000 --> 00:11:11.000 By listening to frame. 00:11:11.000 --> 00:11:16.000 A frame comes in on the port, and what do we do? 00:11:16.000 --> 00:11:20.000 We look at a source MAC of the frame, and then we put an entry in. 00:11:20.000 --> 00:11:22.000 So, that was the source MAC in the frame. 00:11:22.000 --> 00:11:27.000 That's the interface the frame came in on, and that is the VLAN the interface belongs to. 00:11:27.000 --> 00:11:29.000 Okay? 00:11:29.000 --> 00:11:35.000 So, now, what part of the frame does a switch use to make a forwarding decision? 00:11:36.000 --> 00:11:39.000 Excellent, Conrad. 00:11:39.000 --> 00:11:42.000 Yeah, destination MAC address. 00:11:42.000 --> 00:11:44.000 Destination MAC address. 00:11:44.000 --> 00:11:45.000 Okay. 00:11:45.000 --> 00:11:54.000 So, the next question is, when will the switch forward a frame out a specific port? 00:11:55.000 --> 00:12:00.000 When will a switch forward a frame out a very specific port? 00:12:06.000 --> 00:12:11.000 When the destination MAC address is in the MAC address table. 00:12:11.000 --> 00:12:12.000 Yep. 00:12:12.000 --> 00:12:13.000 Absolutely, Conrad. 00:12:13.000 --> 00:12:15.000 Yep. 00:12:15.000 --> 00:12:21.000 When the destination MAC address is in the MAC address table, it is in the MAC address table. 00:12:21.000 --> 00:12:28.000 When the destination MAC address is in the MAC address table, and the destination is in the same VLAN, 00:12:28.000 --> 00:12:32.000 those two values must both be met. 00:12:32.000 --> 00:12:34.000 So, think about this scenario here. 00:12:34.000 --> 00:12:39.000 Let's say PC1 wants to talk to PC2. 00:12:39.000 --> 00:12:44.000 So, PC1's MAC out GIG101. 00:12:44.000 --> 00:12:49.000 PC2's MAC's in the table out GIG102. 00:12:49.000 --> 00:12:54.000 So, the frame arrives in with a source MAC of this and a destination MAC address of this. 00:12:54.000 --> 00:13:01.000 The switch then looks at the destination MAC address and says, oh, I can reach that MAC address out this very specific port. 00:13:01.000 --> 00:13:04.000 So, I will forward it out GIG102. 00:13:05.000 --> 00:13:14.000 If and only if both of these devices are in the same VLAN, VLAN1, VLAN1, yes, okay, I can forward it. 00:13:14.000 --> 00:13:21.000 If not, then I don't forward it because it would be a security violation at that point in time. 00:13:21.000 --> 00:13:25.000 So, what happens when the destination MAC address is not in the same VLAN? 00:13:25.000 --> 00:13:29.000 So, let's say PC2 was in a different VLAN. 00:13:30.000 --> 00:13:34.000 Let's say, folks, that this instead said VLAN10. 00:13:34.000 --> 00:13:36.000 Let's say it said VLAN10. 00:13:36.000 --> 00:13:38.000 So, PC1's in VLAN1. 00:13:38.000 --> 00:13:40.000 PC2's in VLAN10. 00:13:40.000 --> 00:13:42.000 What's going to happen in that case? 00:13:42.000 --> 00:13:44.000 What's going to happen? 00:13:44.000 --> 00:13:46.000 The frame's going to get dropped. 00:13:46.000 --> 00:13:53.000 The frame's going to get dropped because the switch sees that it does not meet the requirements of frame forwarding. 00:13:53.000 --> 00:13:55.000 It's breaking the rule. 00:13:55.000 --> 00:14:04.000 So, if PC1 has the ability to send the frame to a MAC address in a different subnet VLAN broadcast domain, 00:14:04.000 --> 00:14:07.000 the switch is going to stop that from happening. 00:14:07.000 --> 00:14:09.000 Now, you might be saying, wait a second. 00:14:09.000 --> 00:14:12.000 Then how would you talk to somebody in a different VLAN? 00:14:12.000 --> 00:14:13.000 That's different. 00:14:13.000 --> 00:14:14.000 That's different. 00:14:14.000 --> 00:14:16.000 Totally different than what we just talked about. 00:14:16.000 --> 00:14:19.000 So, let's say this is VLAN1 and this is VLAN10. 00:14:19.000 --> 00:14:24.000 Okay, you have your default gateway up here for VLAN1 and you have your default gateway for VLAN10. 00:14:25.000 --> 00:14:31.000 So, the source MAC in this case would be PC1, but the destination MAC would be who? 00:14:31.000 --> 00:14:35.000 The destination MAC would be your default gateway. 00:14:35.000 --> 00:14:36.000 See? 00:14:36.000 --> 00:14:37.000 VLAN1. 00:14:37.000 --> 00:14:38.000 VLAN1. 00:14:38.000 --> 00:14:39.000 Right? 00:14:39.000 --> 00:14:42.000 You forward it to your default gateway. 00:14:42.000 --> 00:14:46.000 Then it gets routed and then it gets sent back in. 00:14:46.000 --> 00:14:48.000 But then what's the source MAC here? 00:14:48.000 --> 00:14:50.000 Source MAC is now this device. 00:14:51.000 --> 00:14:54.000 And the destination MAC is now this device. 00:14:54.000 --> 00:14:57.000 The MAC address changes every time we have to route. 00:14:57.000 --> 00:14:59.000 It's part of our CCNA discussion. 00:14:59.000 --> 00:15:01.000 MAC address changes every time we have to route. 00:15:01.000 --> 00:15:11.000 So, PC1 should never be able to create a frame with a destination MAC address of somebody in another subnet. 00:15:11.000 --> 00:15:12.000 And why is that? 00:15:12.000 --> 00:15:18.000 Because how do you figure out the MAC addresses of somebody in another subnet? 00:15:18.000 --> 00:15:23.000 To figure out the MAC addresses, you use ARP. 00:15:23.000 --> 00:15:24.000 Remember ARP? 00:15:24.000 --> 00:15:26.000 Address Resolution Protocol? 00:15:26.000 --> 00:15:28.000 The favorite protocol of SEALs? 00:15:28.000 --> 00:15:31.000 ARP, ARP, ARP, ARP, ARP, ARP. 00:15:31.000 --> 00:15:36.000 So, this protocol only works inside a subnet VLAN broadcast domain. 00:15:36.000 --> 00:15:41.000 So, when I send out an ARP message saying, hey, if you're so-and-so, give me your MAC address, 00:15:41.000 --> 00:15:45.000 only those devices in my subnet VLAN broadcast domain will actually get that message. 00:15:45.000 --> 00:15:48.000 Nobody else would because it's a broadcast message. 00:15:48.000 --> 00:15:51.000 So, PC1 should never learn PC2's MAC address. 00:15:51.000 --> 00:16:04.000 So, the only way PC1 could create a frame that said source PC1 destination, so source MAC, destination MAC, 00:16:04.000 --> 00:16:06.000 say this is VLAN1 and let's say this is VLAN10, 00:16:06.000 --> 00:16:13.000 the only way I would figure out the destination MAC of PC2 is if they were able to get that information 00:16:13.000 --> 00:16:18.000 in some way, shape, or form sniffing it out or actually going to that physical PC and figuring it out 00:16:18.000 --> 00:16:22.000 by typing in IP config all as an example in a Windows box, but they figured it out somehow 00:16:22.000 --> 00:16:25.000 and then they used software to create fake frames. 00:16:25.000 --> 00:16:27.000 That's the only way they could do that. 00:16:27.000 --> 00:16:32.000 But because the switch won't allow it to happen, when I do execute it, it's not going to be allowed out anyway 00:16:32.000 --> 00:16:35.000 because the switch is going to be like, you can't do that because that destination MAC address 00:16:35.000 --> 00:16:37.000 is not in the same VLAN that you are in. 00:16:37.000 --> 00:16:44.000 That's why it would have to get dropped because it violates the rules of switching. 00:16:44.000 --> 00:16:46.000 Now, when will the frame get flooded? 00:16:46.000 --> 00:16:58.000 Okay, the frame gets flooded any time the destination is FFFFFF, all Fs, that's when a frame gets flooded. 00:16:58.000 --> 00:17:00.000 A broadcast frame or what? 00:17:00.000 --> 00:17:03.000 When the destination is not in the MAC address table. 00:17:03.000 --> 00:17:07.000 So if the destination is not in the MAC address table, our switches are going to flood at all ports 00:17:07.000 --> 00:17:08.000 except the port they came in on. 00:17:08.000 --> 00:17:11.000 If it's a broadcast frame like an ART message or a DHCP discover message, 00:17:11.000 --> 00:17:14.000 flood it at all ports except the port it came in on. 00:17:14.000 --> 00:17:21.000 But we have to remember now, it only gets flooded out the ports that are in the same VLAN. 00:17:21.000 --> 00:17:29.000 So if I have a broadcast frame, it's only going to get flooded out the same ports that are in the same VLAN 00:17:29.000 --> 00:17:32.000 as the device who created it. 00:17:32.000 --> 00:17:35.000 And then if the destination is not in the MAC address table, 00:17:35.000 --> 00:17:39.000 then I'm only going to flood out those ports that are right in the same VLAN as the source. 00:17:39.000 --> 00:17:46.000 That's it. 00:17:46.000 --> 00:17:51.000 So all things that can come up on your certification exam in a multiple choice question, 00:17:51.000 --> 00:17:57.000 just to test you on do you truly understand how VLANs work and how switching works. 00:17:57.000 --> 00:17:59.000 So make sure you're familiar with all of that. 00:17:59.000 --> 00:18:00.000 All right. 00:18:00.000 --> 00:18:04.000 So what we're going to do today is we're going to build a little network. 00:18:04.000 --> 00:18:09.000 We'll say this is 10.0.0.0.24. 00:18:09.000 --> 00:18:11.000 We're going to make this VLAN 10. 00:18:11.000 --> 00:18:13.000 Let's make it for sales. 00:18:13.000 --> 00:18:16.000 We're going to do VLAN 20 here. 00:18:16.000 --> 00:18:20.000 It's going to be 10.0.2.0.24. 00:18:20.000 --> 00:18:23.000 And this is going to be for, let's say, HR today. 00:18:23.000 --> 00:18:29.000 And then we're going to have 10.0.1.0.24. 00:18:29.000 --> 00:18:31.000 This is going to be VLAN 50. 00:18:31.000 --> 00:18:37.000 And this is going to be for, ooh, I don't know, let's say finance for fun. 00:18:37.000 --> 00:18:40.000 And then we're also going to talk about voice VLANs today. 00:18:40.000 --> 00:18:44.000 So let's do VLAN 200. 00:18:44.000 --> 00:18:48.000 And we're going to do 10.0.3.0.24. 00:18:48.000 --> 00:18:49.000 You know, you might be saying, 00:18:49.000 --> 00:19:00.000 that's very poor VLAN IP addressing that you've done here, Raymond. 00:19:00.000 --> 00:19:02.000 That's okay. 00:19:02.000 --> 00:19:03.000 It's all right. 00:19:03.000 --> 00:19:05.000 Because in the grand scheme of things, it doesn't matter. 00:19:05.000 --> 00:19:06.000 That's why I'm doing it this way, 00:19:06.000 --> 00:19:11.000 just to show you that the numbers and the VLANs are what you decide to do. 00:19:11.000 --> 00:19:16.000 And if you are the type of person who says VLAN 10 is going to be 10.0.10.0.24, 00:19:17.000 --> 00:19:20.000 and VLAN 20 is going to be 10.0.20.0.24, 00:19:20.000 --> 00:19:22.000 and VLAN 50 is going to be 10.0.50.0.24. 00:19:22.000 --> 00:19:23.000 Great. That's perfect. 00:19:23.000 --> 00:19:24.000 That's fine. 00:19:24.000 --> 00:19:26.000 You can do it that way if you want to. 00:19:26.000 --> 00:19:28.000 But it's not always going to be that way. 00:19:28.000 --> 00:19:37.000 And it doesn't have to be that way. 00:19:37.000 --> 00:19:39.000 So the moral of the story is that when it comes to VLANs 00:19:39.000 --> 00:19:41.000 and it comes to IP addressing, 00:19:41.000 --> 00:19:44.000 this is something that you have to figure out on paper, 00:19:44.000 --> 00:19:46.000 and it's something that you're going to have to document, 00:19:46.000 --> 00:19:49.000 and it's something that you're going to have to configure and implement. 00:19:49.000 --> 00:19:53.000 And let's just be very clear here that these access layer switches 00:19:53.000 --> 00:19:56.000 don't understand the IP addressing at all. 00:19:56.000 --> 00:19:57.000 It's not going to matter to them. 00:19:57.000 --> 00:20:00.000 It doesn't matter at all. 00:20:00.000 --> 00:20:01.000 Because what are they? 00:20:01.000 --> 00:20:02.000 Layer 2 switches. 00:20:02.000 --> 00:20:04.000 Layer 2 switches that move frames. 00:20:04.000 --> 00:20:06.000 They have no idea what subnets are. 00:20:06.000 --> 00:20:07.000 They don't. 00:20:07.000 --> 00:20:09.000 So the IP addressing is for whose sake? 00:20:09.000 --> 00:20:10.000 My sake. 00:20:10.000 --> 00:20:11.000 My end user's sake. 00:20:11.000 --> 00:20:12.000 My default gateway's sake. 00:20:12.000 --> 00:20:13.000 My router's sakes. 00:20:13.000 --> 00:20:18.000 But not my layer 2 switches. 00:20:18.000 --> 00:20:20.000 All right, so let's start looking at things here. 00:20:20.000 --> 00:20:21.000 Let's go to ASW1 right now. 00:20:21.000 --> 00:20:25.000 We're going to type in our first command, show VLAN brief. 00:20:25.000 --> 00:20:27.000 All right, so when it comes to show VLAN brief, what do we see? 00:20:27.000 --> 00:20:37.000 We see that every single port on this device right now is part of VLAN number 1. 00:20:37.000 --> 00:20:40.000 Every single one of them. 00:20:40.000 --> 00:20:41.000 And what do we call VLAN number 1? 00:20:41.000 --> 00:20:45.000 We call it our default Ethernet VLAN. 00:20:45.000 --> 00:20:51.000 So it only says default there, but it's our default Ethernet VLAN. 00:20:51.000 --> 00:20:52.000 VLAN number 1. 00:20:52.000 --> 00:20:54.000 All ports are part of it. 00:20:54.000 --> 00:20:57.000 Notice it's active. 00:20:57.000 --> 00:21:00.000 Be mindful that you cannot disable this VLAN. 00:21:00.000 --> 00:21:01.000 You cannot shut it down. 00:21:02.000 --> 00:21:28.000 You cannot delete this VLAN no matter what. 00:21:28.000 --> 00:21:36.000 So your default VLAN is VLAN 1, and it must be on and active at all times. 00:21:36.000 --> 00:21:37.000 And why is that? 00:21:37.000 --> 00:21:45.000 Because there's a lot of services behind the scenes that run on your device 00:21:45.000 --> 00:21:50.000 that simply rely on VLAN 1 no matter what. 00:21:50.000 --> 00:21:52.000 So, for example, when you think about Spanning Tree Protocol 00:21:52.000 --> 00:21:59.000 or you think about CDP or LLDP or a multitude of other protocols like VTP, 00:21:59.000 --> 00:22:00.000 they use VLAN 1. 00:22:00.000 --> 00:22:06.000 Whether you're using it or not, they use VLAN 1. 00:22:06.000 --> 00:22:08.000 Also, another thing I want to point out to you is that when you're manipulating 00:22:08.000 --> 00:22:16.000 these VLANs, you're manipulating it for essentially end-user traffic. 00:22:16.000 --> 00:22:19.000 So traffic that has generated somewhere in your environment 00:22:19.000 --> 00:22:26.000 and is flowing through this actual switch, not to the actual switch, 00:22:26.000 --> 00:22:31.000 meaning it's not destined to the switch. 00:22:31.000 --> 00:22:33.000 So you're messing around with user VLANs here. 00:22:33.000 --> 00:22:37.000 You're messing around with voice VLANs here. 00:22:37.000 --> 00:22:42.000 So if it's traffic generated by a switch like Spanning Tree Protocol message 00:22:42.000 --> 00:22:47.000 going to another switch, what I'm doing here doesn't affect that. 00:22:47.000 --> 00:22:54.000 If it's a DTP message for trunking, what I'm doing here with my VLANs doesn't affect that. 00:22:54.000 --> 00:22:56.000 We call that control traffic. 00:22:56.000 --> 00:23:03.000 We call that control traffic. 00:23:03.000 --> 00:23:05.000 All right, that fly is right there on the ceiling. 00:23:05.000 --> 00:23:06.000 Give me one second. 00:23:06.000 --> 00:23:07.000 I can actually reach it. 00:23:07.000 --> 00:23:16.000 Give me one second. 00:23:16.000 --> 00:23:18.000 Got it. 00:23:18.000 --> 00:23:20.000 All right. 00:23:20.000 --> 00:23:21.000 Oops, wrong button. 00:23:21.000 --> 00:23:26.000 Let's go back to this. 00:23:26.000 --> 00:23:34.000 The fly, let's put it this way, has probably woken up from a long sleep over the winter. 00:23:34.000 --> 00:23:40.000 As a result of that, he wasn't very fast or aware that I was even going after him. 00:23:40.000 --> 00:23:43.000 So that's why he didn't get away. 00:23:43.000 --> 00:23:46.000 Didn't have to pull out the fly swatter just yet. 00:23:46.000 --> 00:23:52.000 All right, so let's exit out of here. 00:23:52.000 --> 00:23:56.000 Do show VLAN brief. 00:23:56.000 --> 00:24:02.000 You'll also see that we have a few more VLANs, VLAN 1000, 2000, 3000, 4005. 00:24:02.000 --> 00:24:09.000 These are unsupported on this device, this platform, because these would have been VLANs for FDII 00:24:10.000 --> 00:24:12.000 and Token Ring and FIDINET. 00:24:12.000 --> 00:24:15.000 So FIDI stands for Fiber Distributed Data Interface, something like that. 00:24:15.000 --> 00:24:18.000 It's so old, I can't remember the name of it, and Token Ring Net. 00:24:18.000 --> 00:24:23.000 So these are unsupported on this switch because it's purely an Ethernet switch, 00:24:23.000 --> 00:24:26.000 but there are switches out there that potentially support it. 00:24:26.000 --> 00:24:30.000 As a result of that, the iOS, since it's usable on many different switches, 00:24:30.000 --> 00:24:35.000 you would see that on your switch even if your switch couldn't support it, 00:24:35.000 --> 00:24:37.000 like this particular switch here. 00:24:37.000 --> 00:24:42.000 You won't be tested on those on the certification exam, but that's why they're there. 00:24:42.000 --> 00:24:45.000 They're for old-school technologies that are really not around anymore 00:24:45.000 --> 00:25:01.000 and therefore unsupported on most of our products and platforms. 00:25:01.000 --> 00:25:08.000 How many total VLANs can we create on our device? 00:25:08.000 --> 00:25:11.000 Let's type in VLAN? 00:25:11.000 --> 00:25:18.000 And you'll see here that it says we can create VLANs 1 through 4094. 00:25:18.000 --> 00:25:31.000 VLANs range from 0 to 4095 for a total of 4096 VLANs. 00:25:31.000 --> 00:25:33.000 You can't use 0. 00:25:33.000 --> 00:25:38.000 You can't use 4095. 00:25:38.000 --> 00:25:46.000 1 is our default Ethernet VLAN, 1000, 2, 3, 4, and 5 are for FIDI and Token Ring. 00:25:46.000 --> 00:25:48.000 But you can pretty much use anything else. 00:25:48.000 --> 00:25:55.000 However, there are some other technologies on your device that might be getting in your way 00:25:55.000 --> 00:25:58.000 from you being able to use them. 00:25:58.000 --> 00:26:04.000 For example, if I create something like VLAN 10, that works no problem. 00:26:04.000 --> 00:26:11.000 Do show VLAN brief. 00:26:11.000 --> 00:26:14.000 And you'll see that VLAN 10 now exists. 00:26:14.000 --> 00:26:21.000 But let's try and create something like VLAN 1009. 00:26:21.000 --> 00:26:24.000 Looks like I was able to do that. 00:26:24.000 --> 00:26:29.000 But let's exit out because it's when you exit out that it actually executes your commands. 00:26:29.000 --> 00:26:32.000 In this case, it says I cannot do that. 00:26:32.000 --> 00:26:37.000 It failed to create my VLANs, 1009. 00:26:37.000 --> 00:26:44.000 And the reason why, as you'll see, is because of something called VLAN chunking protocol. 00:26:44.000 --> 00:26:53.000 When Cisco created their iOS for their switches, as you see here, 00:26:53.000 --> 00:27:03.000 we were dealing with a timeframe whereby there was not a possibility for 4096 VLANs. 00:27:03.000 --> 00:27:04.000 That's right. 00:27:04.000 --> 00:27:07.000 We had VLANs from 0 through 1005. 00:27:07.000 --> 00:27:08.000 That's what we had. 00:27:08.000 --> 00:27:10.000 That is what we had. 00:27:10.000 --> 00:27:20.000 So this number that you see here used to be 1 through 1005. 00:27:20.000 --> 00:27:26.000 And you can't do 2, 3, 4, and 5 because they're reserved. 00:27:26.000 --> 00:27:30.000 Because back at that time, VLANs were not a standard. 00:27:30.000 --> 00:27:34.000 And since VLANs were not a standard, vendors were doing it themselves, 00:27:34.000 --> 00:27:36.000 and Cisco on their products did it themselves. 00:27:36.000 --> 00:27:37.000 Right? 00:27:37.000 --> 00:27:38.000 These are VLANs. 00:27:38.000 --> 00:27:39.000 This is how we're implementing them. 00:27:39.000 --> 00:27:42.000 You can do everything from 1 to 1005. 00:27:42.000 --> 00:27:45.000 And as a result, they also created at the same time other technologies, 00:27:45.000 --> 00:27:48.000 like VLAN chunking protocol, as an example. 00:27:48.000 --> 00:27:53.000 And because of the mode of VLAN chunking protocol, totally different service, 00:27:53.000 --> 00:27:55.000 because of VLAN chunking protocol mode, 00:27:56.000 --> 00:28:01.000 it prevents me from creating anything higher than VLAN 1005. 00:28:01.000 --> 00:28:06.000 I can create everything up to 1001, but I cannot go any higher than that, 00:28:06.000 --> 00:28:08.000 all because of something else. 00:28:08.000 --> 00:28:09.000 And why am I telling you this? 00:28:09.000 --> 00:28:13.000 Because I always want us to remember going forward that everything you do on 00:28:13.000 --> 00:28:17.000 your Cisco devices, every service and technology you use, 00:28:17.000 --> 00:28:21.000 there's going to be some other service or technology that it either depends on 00:28:21.000 --> 00:28:25.000 or works with or interferes with, like we see here. 00:28:25.000 --> 00:28:29.000 Let's say you wanted to create VLAN 1009. 00:28:29.000 --> 00:28:34.000 You can't, using the default configuration of your switch. 00:28:34.000 --> 00:28:38.000 You would have to understand, how does VTP also affect me? 00:28:38.000 --> 00:28:41.000 And these are some of the things that could show up on a certification exam 00:28:41.000 --> 00:28:42.000 at this level, 00:28:42.000 --> 00:28:47.000 understanding how other services can negatively affect another service. 00:28:47.000 --> 00:28:51.000 So, for example, if we type in do show VTP status right now, 00:28:51.000 --> 00:28:57.000 you'll see that I am in server mode and we're using version one. 00:28:57.000 --> 00:29:07.000 So, because we're using server mode and we are using version one, 00:29:07.000 --> 00:29:14.000 I am not allowed to create anything more than VLAN 1005. 00:29:15.000 --> 00:29:20.000 However, if we change the mode to transparent, 00:29:20.000 --> 00:29:23.000 I'll show you how to do that later in our VTP discussion, 00:29:23.000 --> 00:29:28.000 and we leave it as version one, so transparent and version one, 00:29:28.000 --> 00:29:35.000 then I can create VLAN 1009, no problem, anything higher than that. 00:29:35.000 --> 00:29:38.000 So, if you're in transparent mode, 00:29:38.000 --> 00:29:43.000 you'll be able to create VLANs up to those numbers there. 00:29:43.000 --> 00:29:46.000 But if you're in server mode with version one, you can't. 00:29:46.000 --> 00:29:49.000 The other option is to change it to version three. 00:29:49.000 --> 00:29:53.000 So, if you change it to version three VTP, then server mode, 00:29:53.000 --> 00:29:57.000 client mode, and transparent mode all support all the VLANs. 00:29:57.000 --> 00:30:01.000 Just little things to keep in mind as we go through things, 00:30:01.000 --> 00:30:03.000 because they could show up on the exam. 00:30:03.000 --> 00:30:09.000 If all of a sudden you had a question that says you're trying to create VLAN 2000, 00:30:10.000 --> 00:30:17.000 but you get the error message, failed to create VLAN 2000, why is that? 00:30:17.000 --> 00:30:19.000 Well, I mean, it could be a lot of different reasons, 00:30:19.000 --> 00:30:23.000 but if you look at the list and what the list says, 00:30:23.000 --> 00:30:26.000 you're using VTP version one and mode server, 00:30:26.000 --> 00:30:28.000 well, then that's probably the reason why. 00:30:28.000 --> 00:30:32.000 I would be picking that 100% of the time on an exam question, 00:30:32.000 --> 00:30:37.000 if that ever came up. 00:30:38.000 --> 00:30:39.000 Just keep that in mind. 00:30:39.000 --> 00:30:40.000 All right. 00:30:40.000 --> 00:30:43.000 So, I'll show you how to mess around with VTP later on. 00:30:43.000 --> 00:30:45.000 Back to our VLANs. 00:30:45.000 --> 00:30:47.000 Do show VLAN brief. 00:30:47.000 --> 00:30:50.000 So, folks, as we create VLANs, let's create some more VLANs here. 00:30:50.000 --> 00:30:54.000 Let's create, for example, VLAN 20. 00:30:54.000 --> 00:31:00.000 Let's create VLAN 30. 00:31:00.000 --> 00:31:04.000 Let's create VLAN 200. 00:31:04.000 --> 00:31:06.000 Do show VLAN brief. 00:31:06.000 --> 00:31:09.000 You'll see they're all in here and they all have default names, VLAN 10, 00:31:09.000 --> 00:31:12.000 VLAN 20, VLAN 30, VLAN 200. 00:31:12.000 --> 00:31:13.000 You can name them if you want to. 00:31:13.000 --> 00:31:18.000 So, if you go VLAN 10, you might want to name it sales data VLAN 00:31:18.000 --> 00:31:20.000 or data traffic for that VLAN, 00:31:20.000 --> 00:31:25.000 just to show you how the name would change in that particular case. 00:31:25.000 --> 00:31:28.000 One thing I always want you to remember for the certification exam is that 00:31:28.000 --> 00:31:31.000 what they put here might not be exactly what the VLAN is for. 00:31:31.000 --> 00:31:32.000 Always remember that. 00:31:32.000 --> 00:31:35.000 Always remember that. 00:31:35.000 --> 00:31:39.000 Because we're going to be doing VLAN 200 as our voice VLAN, correct? 00:31:39.000 --> 00:31:47.000 So, what if they did something like this on the exam? 00:31:47.000 --> 00:31:52.000 And you were looking at the output, and the output here said voice, 00:31:52.000 --> 00:31:55.000 but the diagram said VLAN 200 is supposed to be voice. 00:31:55.000 --> 00:31:59.000 What I want you to realize is that don't ever go by the name. 00:31:59.000 --> 00:32:01.000 The name could be totally wrong. 00:32:01.000 --> 00:32:02.000 Use the name to guide you, 00:32:02.000 --> 00:32:05.000 and if the name given matches what's on the diagram, then you know it's fine. 00:32:05.000 --> 00:32:08.000 If the name given doesn't match the diagram, don't trust the names. 00:32:08.000 --> 00:32:11.000 Because you can name it anything you want, and it doesn't matter, 00:32:11.000 --> 00:32:12.000 in the grand scheme of things. 00:32:12.000 --> 00:32:14.000 It just messes you up as a human being. 00:32:14.000 --> 00:32:15.000 That's all it does. 00:32:15.000 --> 00:32:18.000 The odds of them doing that to you on the exam, though, is very slim, 00:32:18.000 --> 00:32:19.000 but you never know. 00:32:19.000 --> 00:32:20.000 They could totally do that to you, 00:32:20.000 --> 00:32:24.000 and I'd hate for you to mess up on a question only because they named it 00:32:24.000 --> 00:32:27.000 something that it was not, just to try and trick you, 00:32:27.000 --> 00:32:29.000 which is dirty for them to do that. 00:32:29.000 --> 00:32:31.000 But it has happened in the past. 00:32:31.000 --> 00:32:34.000 I just can't confirm if it's going to happen to you this time. 00:32:34.000 --> 00:32:36.000 So just keep that in mind. 00:32:36.000 --> 00:32:39.000 All right, so we have our sales VLANs. 00:32:39.000 --> 00:32:41.000 We have our HR VLAN. 00:32:41.000 --> 00:32:42.000 We have our finance VLAN. 00:32:42.000 --> 00:32:44.000 Oh, that's wrong. 00:32:44.000 --> 00:32:45.000 It's supposed to be VLAN 50, right? 00:32:45.000 --> 00:32:48.000 Nobody called me out on that. 00:32:48.000 --> 00:32:50.000 All right, let's delete it. 00:32:50.000 --> 00:32:52.000 Let me show you how to delete it, Dan. 00:32:52.000 --> 00:32:54.000 No VLAN 30. 00:32:54.000 --> 00:32:56.000 So VLAN 30 is gone. 00:32:56.000 --> 00:32:58.000 VLAN 50 is now there. 00:33:02.000 --> 00:33:06.000 All right, back to it. 00:33:06.000 --> 00:33:07.000 There we go. 00:33:07.000 --> 00:33:09.000 10, 20, 50, 200. 00:33:09.000 --> 00:33:13.000 Perfect. 00:33:13.000 --> 00:33:15.000 10, 20, 50, 200. 00:33:15.000 --> 00:33:16.000 Looks good. 00:33:16.000 --> 00:33:17.000 Looks good. 00:33:17.000 --> 00:33:18.000 Okay, good. 00:33:18.000 --> 00:33:20.000 So the next question I have for you folks is, 00:33:20.000 --> 00:33:24.000 where is this information being saved? 00:33:24.000 --> 00:33:26.000 Where is this information being saved? 00:33:27.000 --> 00:33:30.000 Okay, VLAN database, excellent. 00:33:30.000 --> 00:33:32.000 Where is the VLAN database stored? 00:33:32.000 --> 00:33:34.000 Andrew says VLAN.dat, excellent. 00:33:34.000 --> 00:33:36.000 That's the name of the file. 00:33:36.000 --> 00:33:40.000 So where is the VLAN database called VLAN.dat stored? 00:33:40.000 --> 00:33:42.000 Jeffrey says flash, good job. 00:33:42.000 --> 00:33:44.000 Where is that VLAN database stored? 00:33:44.000 --> 00:33:46.000 Jeffrey says flash, excellent. 00:33:46.000 --> 00:33:50.000 Where is the VLAN database called VLAN.dat stored? 00:33:50.000 --> 00:33:52.000 Jeffrey says flash, absolutely. 00:33:52.000 --> 00:33:57.000 So let's type in do show flash. 00:33:57.000 --> 00:34:03.000 And you'll see that I have the VLAN.dat filed listed right here. 00:34:03.000 --> 00:34:06.000 So that is where everything is being stored by default for my VLANs. 00:34:06.000 --> 00:34:10.000 It's not in the running config. 00:34:10.000 --> 00:34:21.000 So if we type in do show run, we're going to see here that there is nothing in our running config related to VLANs except for this command right here. 00:34:21.000 --> 00:34:23.000 Okay. 00:34:23.000 --> 00:34:25.000 That was it. 00:34:25.000 --> 00:34:27.000 But where is VLAN 10, 20, 50, 200? 00:34:27.000 --> 00:34:29.000 It's not there. 00:34:29.000 --> 00:34:31.000 It's in the flash.dat file. 00:34:31.000 --> 00:34:34.000 So when I type in do show flash, it's not there. 00:34:35.000 --> 00:34:41.000 So when I type in do show flash, no, sorry, do show VLAN, I am looking at what is stored right now in regards to these. 00:34:41.000 --> 00:34:44.000 I am looking at what is stored in that VLAN.dat file. 00:34:44.000 --> 00:34:47.000 And there's other stuff in that VLAN.dat file as well. 00:34:47.000 --> 00:34:51.000 But usually when we type in brief, we're just getting a snapshot of the top stuff. 00:34:51.000 --> 00:34:53.000 That's it. 00:34:53.000 --> 00:34:55.000 Okay. 00:34:55.000 --> 00:34:59.000 Now, if you change your VTP, and this is happening because of the VLAN. 00:34:59.000 --> 00:35:05.000 Now, if you change your VTP, and this is happening because of our VTP mode. 00:35:05.000 --> 00:35:06.000 That's right. 00:35:06.000 --> 00:35:09.000 This is happening because of our VTP mode. 00:35:09.000 --> 00:35:20.000 So if we type in do show VTP again, status, because our VTP mode is server, we store it in the VLAN.dat file. 00:35:20.000 --> 00:35:24.000 If it was client mode, it would also be in the VLAN.dat file. 00:35:24.000 --> 00:35:37.000 But if we change our VTP mode to transparent, we're going to see now by typing do show run that everything is where? 00:35:37.000 --> 00:35:43.000 Now in the running config. 00:35:43.000 --> 00:35:46.000 So think about it this way. 00:35:46.000 --> 00:35:47.000 Think about it this way. 00:35:47.000 --> 00:35:57.000 If it's stored in the VLAN.dat file in Flash, you don't have to save your VLANs when you create them because it's automatically saved for you. 00:35:57.000 --> 00:36:05.000 However, you still have to remember that if the Flash file gets damaged or corrupt, well, your VLAN information is gone. 00:36:05.000 --> 00:36:13.000 So you'll definitely want to store a copy of your VLAN.dat file somewhere else on a server as well as a backup. 00:36:13.000 --> 00:36:20.000 Just like you'd store your startup config somewhere as a backup just in case the startup config gets corrupted on your device. 00:36:20.000 --> 00:36:27.000 However, if you are in transparent mode of VTP, then what does that mean? 00:36:27.000 --> 00:36:32.000 If you're in VTP mode transparent, any VLAN change you make is not automatically saved. 00:36:32.000 --> 00:36:41.000 You're going to have to do a copy run start, copy run start, copy run start every time you make a VLAN change to save your changes. 00:36:41.000 --> 00:36:45.000 Or else every change you make is not going to be saved. 00:36:45.000 --> 00:36:48.000 So think about that from an exam standpoint. 00:36:48.000 --> 00:36:54.000 If you're talking about configuring, verifying, or troubleshooting VLAN information, and they're showing you a little bit of VTP information, 00:36:54.000 --> 00:37:00.000 they're showing you some running config information, or not even showing you running config information, they're just talking about VLANs. 00:37:00.000 --> 00:37:07.000 If you look at VTP and it says transparent mode, well, you know you're going to have to do copy run stars in order to save your config of any VLAN adjustments. 00:37:07.000 --> 00:37:12.000 But if it's VLAN.dat file, then you would not have to because those would be saved. 00:37:12.000 --> 00:37:15.000 But it's only the stuff directly related to the VLANs. 00:37:15.000 --> 00:37:23.000 So, for example, when we start moving our ports to the respective VLANs, that stuff's not stored in the VLAN database. 00:37:23.000 --> 00:37:28.000 So if we scroll back up here, this stuff's not stored in the VLAN database, the ports. 00:37:28.000 --> 00:37:30.000 This is part of your running config. 00:37:30.000 --> 00:37:33.000 This is part of your startup config, not the VLAN.dat file. 00:37:34.000 --> 00:37:47.000 The VLAN.dat file is anything related to the actual VLAN creation, the VLAN name itself, the state of the VLAN, the VLAN-specific stuff, but not the port stuff related to the actual VLAN. 00:37:47.000 --> 00:37:50.000 I'm going to move that back to server mode. 00:37:50.000 --> 00:38:01.000 And when you move it back to server mode, it'll go ahead and take everything out of the running config now and put it back into the VLAN.dat file. 00:38:01.000 --> 00:38:03.000 So you'll see it's no longer in the running config. 00:38:03.000 --> 00:38:17.000 So if I made any changes while in transparent mode, those would have been then brought into the VLAN.dat file for me to save them back to the VLAN.dat file. 00:38:17.000 --> 00:38:23.000 So you can go back and forth if you want to from server to transparent, transparent back to server, and it just copies what's in there. 00:38:23.000 --> 00:38:26.000 And then when you go back to server mode, it'll go back in. 00:38:27.000 --> 00:38:34.000 More on VTP later, but you can just see already how understanding how one technology affects everything else is really important. 00:38:34.000 --> 00:38:36.000 And that's true about Spanning Tree Protocol as well. 00:38:36.000 --> 00:38:41.000 Most people don't realize the massive effect that Spanning Tree Protocol has on your Layer 2 environment. 00:38:41.000 --> 00:38:47.000 And if you don't fully understand Spanning Tree Protocol, your environment may not be performing as optimally as you want. 00:38:47.000 --> 00:38:50.000 That's why I said performing as optimally as you want. 00:38:50.000 --> 00:38:53.000 So we'll talk about that when we get to our Spanning Tree discussion. 00:38:53.000 --> 00:38:59.000 And how also doing certain things in trunking can affect Spanning Tree Protocol or doing certain things can affect this, that. 00:38:59.000 --> 00:39:02.000 We'll make sure we cover all of that, that we can. 00:39:02.000 --> 00:39:03.000 All right. 00:39:03.000 --> 00:39:05.000 So now that we have our VLANs created, what do we want to do next? 00:39:05.000 --> 00:39:16.000 We want to place our VLANs or place our ports and their respective VLANs based on our topology. 00:39:16.000 --> 00:39:29.000 So right now if we type in do show VLAN brief, every single one of our ports are still in VLAN 1. 00:39:29.000 --> 00:39:37.000 So these two ports, gigabit 1 and gigabit 2, have to be moved to VLAN 10. 00:39:37.000 --> 00:39:39.000 So let's go ahead and do that right now. 00:39:39.000 --> 00:39:48.000 So we're going to say interface, range, gigabit Ethernet, 1 slash 0 slash 1 and 2. 00:39:48.000 --> 00:39:54.000 And then we'll say switch port, access, VLAN 10. 00:39:54.000 --> 00:39:58.000 That's the command to move you from one VLAN to another VLAN. 00:39:58.000 --> 00:40:09.000 If I type in do show run, pipe to section or pipe to not even pipe, show run interface, gigabit Ethernet, 1 slash 0 slash 1. 00:40:09.000 --> 00:40:12.000 We'll see here I'm part of VLAN 10 now. 00:40:12.000 --> 00:40:15.000 Type in do show VLAN brief. 00:40:15.000 --> 00:40:19.000 We'll see that gigabit 1 and 2 are no longer listed here. 00:40:19.000 --> 00:40:21.000 They're now listed down here as part of VLAN 10. 00:40:22.000 --> 00:40:32.000 And if we type in the command do show interface gigabit Ethernet, 1 slash 0 slash 1, and we tack on the switch port keyword, 00:40:32.000 --> 00:40:45.000 we're going to be able to see in this output that I am a member of VLAN 10, which is name sales. 00:40:45.000 --> 00:40:51.000 Let's do the same thing for gigabit 1 slash 0 slash 3, but it's got to go in VLAN 20. 00:40:51.000 --> 00:40:58.000 So interface gigabit 1 slash 0 slash 3, switch port, access, VLAN. 00:40:58.000 --> 00:41:00.000 We said 20. 00:41:00.000 --> 00:41:09.000 So do show run interface gigabit Ethernet, 1 slash 0 slash 3. 00:41:09.000 --> 00:41:18.000 Do show run or do show interface gigabit Ethernet, so 0 slash 3, switch port. 00:41:18.000 --> 00:41:24.000 And you'll see I'm part of VLAN 20, and the name is VLAN 0020. 00:41:24.000 --> 00:41:29.000 Do show VLAN brief. 00:41:29.000 --> 00:41:34.000 A question right now, what would happen if VLAN 10 got deleted, folks? 00:41:35.000 --> 00:41:39.000 If VLAN 10 got deleted, what would happen to these two ports right here? 00:41:39.000 --> 00:41:44.000 For example, would they get deleted, no longer exist, would they go back to VLAN 1? 00:41:44.000 --> 00:41:47.000 What would happen if VLAN 10 got deleted? 00:41:47.000 --> 00:42:09.000 So if we type in do show VLAN brief, we're going to see here that they're nowhere to be found. 00:42:09.000 --> 00:42:12.000 And why is that? 00:42:12.000 --> 00:42:16.000 Because they're still configured to be where? 00:42:16.000 --> 00:42:17.000 Where? 00:42:17.000 --> 00:42:22.000 They're still configured as part of VLAN 10. 00:42:22.000 --> 00:42:24.000 That config didn't change. 00:42:24.000 --> 00:42:33.000 Just because the VLAN's gone doesn't mean that the interface config has changed. 00:42:33.000 --> 00:42:41.000 And if we look at the output of show interface gigabit 1 slash 0 slash 1, switch port, 00:42:41.000 --> 00:42:55.000 notice it says we're still part of VLAN 10, but VLAN 10 is inactive, meaning it does not exist. 00:42:55.000 --> 00:43:07.000 So if we add VLAN 10 back in, and then we look at our output again, you'll see that now it shows 00:43:07.000 --> 00:43:10.000 that VLAN 10 is no longer inactive. 00:43:10.000 --> 00:43:18.000 Type in do show VLAN brief, we'll see that the interfaces are now back with VLAN 10. 00:43:40.000 --> 00:43:47.000 Let's talk about voice VLANs now on our Cisco IOS Catalyst switches. 00:43:47.000 --> 00:43:52.000 So when we think about a phone, what do we need to be aware of when it comes to our phones? 00:43:52.000 --> 00:44:00.000 Our Cisco phones are designed in a way so that way there we only have to consume one physical port on our switches. 00:44:00.000 --> 00:44:04.000 So, for example, here's my switch. 00:44:04.000 --> 00:44:08.000 My port, let's say, would connect to here. 00:44:08.000 --> 00:44:14.000 This port then goes to the PC, and this wouldn't be a physical port, it would be a virtual port, 00:44:14.000 --> 00:44:15.000 but it's connected to what? 00:44:15.000 --> 00:44:23.000 The application-specific integrated circuits of the actual phone. 00:44:23.000 --> 00:44:25.000 And so what does this allow us to do? 00:44:25.000 --> 00:44:31.000 It allows us to only consume one port on the switch, and therefore traffic from the PC enters the phone, 00:44:31.000 --> 00:44:33.000 gets forwarded out to the switch. 00:44:34.000 --> 00:44:40.000 Traffic from the phone gets forwarded out to the switch. 00:44:40.000 --> 00:44:44.000 And so we place our phones in their own VLANs. 00:44:44.000 --> 00:44:45.000 Why? 00:44:45.000 --> 00:44:46.000 That's right. 00:44:46.000 --> 00:44:48.000 So we can implement quality of service. 00:44:48.000 --> 00:44:53.000 So we can do traffic differentiation. 00:44:53.000 --> 00:44:56.000 So traffic can be differentiated. 00:44:56.000 --> 00:45:00.000 Because our voice traffic is very, very delicate. 00:45:00.000 --> 00:45:02.000 Voice traffic requires what? 00:45:02.000 --> 00:45:09.000 Jitter less than 30 milliseconds one way, delay less than 150 milliseconds one way, packet loss that is less than 1% one way. 00:45:09.000 --> 00:45:13.000 And then we want to make sure that we can prioritize all of our traffic. 00:45:13.000 --> 00:45:19.000 So if there is something called congestion, then we can move the voice traffic to the front of the line on our switches 00:45:19.000 --> 00:45:26.000 and our routers and our firewalls, and that voice traffic can be processed first before other types of traffic. 00:45:27.000 --> 00:45:33.000 So we do that by using quality of service and by marking our traffic. 00:45:33.000 --> 00:45:37.000 Marking our traffic, for example, with a COS value of 5. 00:45:37.000 --> 00:45:42.000 Now, there's other values that you'd find in your IP headers, DSCP values and different things like that. 00:45:42.000 --> 00:45:44.000 But we're just talking about our frames right now. 00:45:44.000 --> 00:45:48.000 So our frame would have a COS value of 5 inside of it. 00:45:48.000 --> 00:45:53.000 So in our particular case, we are going to have voice VLAN 200 as an example. 00:45:54.000 --> 00:46:06.000 So how do I now make sure that this port knows that we have a voice VLAN and a data VLAN, meaning VLAN for the PC, a data VLAN, 00:46:06.000 --> 00:46:11.000 or we called it in our config, the access VLAN. 00:46:11.000 --> 00:46:15.000 The access VLAN switch port, access VLAN 10. 00:46:16.000 --> 00:46:19.000 And if we look at our output right here, what does it say? 00:46:19.000 --> 00:46:23.000 It actually says access mode VLAN. 00:46:23.000 --> 00:46:31.000 So on the exam, they might use the word access VLAN, or they might use data VLAN, or they might use the VLAN for the PC. 00:46:31.000 --> 00:46:36.000 However they say it, they're referring to the traffic coming from the PC in that case. 00:46:36.000 --> 00:46:42.000 Voice traffic will be specifically labeled as voice on the exam, voice traffic, voice VLAN. 00:46:43.000 --> 00:46:49.000 So how does the switch port know the difference between voice traffic and our data traffic? 00:46:49.000 --> 00:46:53.000 Different VLANs, different VLANs. 00:46:53.000 --> 00:46:54.000 Absolutely. 00:46:54.000 --> 00:46:57.000 So here is the config to add it. 00:46:57.000 --> 00:47:00.000 I'm going to do it right now in our environment though. 00:47:00.000 --> 00:47:03.000 So we know that VLAN 200 is going to be for voice. 00:47:03.000 --> 00:47:11.000 So if we go to, for example, interface, range, gigabit ethernet, one size zero slash, one through three in our example right now, 00:47:11.000 --> 00:47:14.000 because I'm going to put all of them in that voice VLAN. 00:47:14.000 --> 00:47:20.000 We're going to type in switch port, voice VLAN, and then put the VLAN number of 200. 00:47:20.000 --> 00:47:25.000 So my switch does not know that this is for voice, okay? 00:47:25.000 --> 00:47:26.000 It doesn't. 00:47:26.000 --> 00:47:28.000 Unless, until I do what? 00:47:28.000 --> 00:47:31.000 Until I actually configure this command on an interface. 00:47:31.000 --> 00:47:35.000 Now it knows like, oh, okay, that VLAN is for voice. 00:47:35.000 --> 00:47:36.000 That's how it knows now. 00:47:36.000 --> 00:47:39.000 Other than that, it had no idea what it was for. 00:47:39.000 --> 00:47:44.000 Likewise, it had no idea what VLAN 10 was for until I configured what? 00:47:44.000 --> 00:47:46.000 Switch port access VLAN 10. 00:47:46.000 --> 00:47:48.000 Then it knows, oh, it's data traffic. 00:47:48.000 --> 00:47:50.000 It's not voice traffic. 00:47:50.000 --> 00:47:53.000 So let's go ahead and take a peek at our output now, 00:47:53.000 --> 00:48:00.000 and you'll see that you have your access mode VLAN 10 and your voice VLAN of 200. 00:48:00.000 --> 00:48:05.000 So we now type in do show VLAN brief. 00:48:05.000 --> 00:48:12.000 You'll see that we have now gig 101 showing up here under VLAN 10 00:48:12.000 --> 00:48:14.000 and 101 showing up as VLAN 200. 00:48:14.000 --> 00:48:19.000 The only way you're going to see an interface listed twice in this output, folks, 00:48:19.000 --> 00:48:23.000 is if the interface is part of a data VLAN, an access VLAN, and a voice VLAN. 00:48:23.000 --> 00:48:25.000 That's it. 00:48:25.000 --> 00:48:28.000 You cannot have one interface and two voice VLANs. 00:48:28.000 --> 00:48:31.000 You cannot have one interface and two access data VLANs. 00:48:31.000 --> 00:48:33.000 You cannot have that. 00:48:33.000 --> 00:48:37.000 So that's why, for example, in the exam, don't necessarily always trust the labeling. 00:48:37.000 --> 00:48:40.000 So what if they accidentally label this as voice and this as data? 00:48:40.000 --> 00:48:43.000 How would you know for sure which one's which? 00:48:43.000 --> 00:48:44.000 Look at the config. 00:48:44.000 --> 00:48:46.000 That's how you are going to know. 00:48:46.000 --> 00:48:51.000 For example, do show run interface gigabit ethernet 1 size 0 size 1 is one way to check. 00:48:51.000 --> 00:48:56.000 You know that regardless of how this is labeled, right, it doesn't matter. 00:48:56.000 --> 00:48:58.000 This is what tells the truth. 00:48:58.000 --> 00:49:02.000 This would be for access traffic slash data traffic. 00:49:02.000 --> 00:49:06.000 This would be for voice traffic regardless of what they had here as the name, 00:49:06.000 --> 00:49:09.000 the description. 00:49:09.000 --> 00:49:13.000 So if they named it voice and this is access VLAN, 00:49:13.000 --> 00:49:15.000 they're trying to mess with your head on the exam. 00:49:15.000 --> 00:49:17.000 Don't let them trick you that way. 00:49:17.000 --> 00:49:23.000 This is the deciding factor as to what type of traffic it is for that VLAN on that port. 00:49:23.000 --> 00:49:25.000 That's how it works. 00:49:25.000 --> 00:49:31.000 So if we type now do show interface gigabit 1 size 0 size 1 switch port, 00:49:31.000 --> 00:49:37.000 we'll see that we have another way to verify. 00:49:37.000 --> 00:49:42.000 If it says VLAN 10 is access mode, you know no matter what this is labeled as, 00:49:42.000 --> 00:49:47.000 it doesn't matter because this is telling the 100% truth based on this 00:49:47.000 --> 00:49:49.000 configuration right here. 00:49:49.000 --> 00:49:53.000 Likewise, this here is telling 100% truth based on the configuration right here 00:49:53.000 --> 00:49:55.000 regardless of what this says right here. 00:49:55.000 --> 00:49:58.000 Because that is just for you to describe it based on. 00:49:58.000 --> 00:50:00.000 And the switch doesn't care about that right there. 00:50:00.000 --> 00:50:04.000 Literally, the switch does not care about these names that you have right here. 00:50:04.000 --> 00:50:05.000 It doesn't even reference them. 00:50:05.000 --> 00:50:07.000 It doesn't even know what it means. 00:50:07.000 --> 00:50:08.000 That's for you. 00:50:08.000 --> 00:50:09.000 That's for you. 00:50:09.000 --> 00:50:11.000 Likewise here, that's for you regardless of what it says. 00:50:11.000 --> 00:50:14.000 So if that said voice here and that said data here, 00:50:14.000 --> 00:50:17.000 you know that they just mislabeled it. 00:50:17.000 --> 00:50:18.000 They mislabeled it. 00:50:18.000 --> 00:50:20.000 That's all, okay? 00:50:20.000 --> 00:50:21.000 Don't let that throw you off. 00:50:33.000 --> 00:50:36.000 Okay, so if you did switch port access VLAN 200, 00:50:36.000 --> 00:50:41.000 then what would happen is that in this scenario, this specific scenario, 00:50:41.000 --> 00:50:45.000 then VLAN 10 would be replaced with VLAN 200. 00:50:45.000 --> 00:50:48.000 So VLAN 200 would no longer be voice. 00:50:48.000 --> 00:50:50.000 VLAN 200 would be here. 00:50:50.000 --> 00:50:54.000 And then the switch would not necessarily recognize it as voice traffic. 00:50:54.000 --> 00:50:55.000 That's all. 00:50:55.000 --> 00:50:59.000 Would not necessarily recognize it as voice traffic unless you did other 00:50:59.000 --> 00:51:02.000 configs on the switch to make it recognize it as voice traffic. 00:51:05.000 --> 00:51:07.000 Now, if it was just a port all by itself 00:51:07.000 --> 00:51:11.000 and you accidentally typed in access mode 200, again, 00:51:11.000 --> 00:51:14.000 depending on how the rest of the switch is configured for quality of service 00:51:14.000 --> 00:51:17.000 and different things like that and marking would ultimately determine 00:51:17.000 --> 00:51:19.000 whether it's treated as voice traffic or not. 00:51:19.000 --> 00:51:21.000 Because once the traffic arrives on the switch, 00:51:21.000 --> 00:51:23.000 the switch has to make a decision. 00:51:23.000 --> 00:51:25.000 If it's voice traffic, well, I'm going to treat it as voice traffic. 00:51:25.000 --> 00:51:27.000 If it's data traffic, I'm going to treat it as data. 00:51:27.000 --> 00:51:29.000 If the switch thinks it's data traffic, then what's going to happen? 00:51:29.000 --> 00:51:31.000 It's going to treat it as data traffic. 00:51:31.000 --> 00:51:32.000 Is it still going to work? 00:51:32.000 --> 00:51:33.000 Possibly. 00:51:33.000 --> 00:51:34.000 Possibly not. 00:51:34.000 --> 00:51:36.000 It really depends on the rest of the network. 00:51:36.000 --> 00:51:38.000 So what would happen? 00:51:38.000 --> 00:51:39.000 Would the phone still work? 00:51:39.000 --> 00:51:42.000 More than likely, yes, possibly, maybe. 00:51:43.000 --> 00:51:45.000 There's no definitive perfect answer to that question 00:51:45.000 --> 00:51:48.000 because it would rely on 100 other things being configured properly or not. 00:51:51.000 --> 00:51:53.000 But the idea here is if it did work, 00:51:53.000 --> 00:51:57.000 you probably wouldn't get the QoS that you expect to get, 00:51:57.000 --> 00:52:03.000 and, therefore, the phone conversation might not be as clean 00:52:03.000 --> 00:52:05.000 and clear as it should be. 00:52:05.000 --> 00:52:07.000 Make sense? 00:52:08.000 --> 00:52:12.000 There's too many variables in play here to answer that question perfectly. 00:52:16.000 --> 00:52:17.000 Okay. 00:52:17.000 --> 00:52:18.000 So far, so good. 00:52:18.000 --> 00:52:22.000 Now, a lot of people ask, well, Raymond, how does that actually work now? 00:52:22.000 --> 00:52:24.000 So let's talk about this. 00:52:24.000 --> 00:52:25.000 We have our PC frame. 00:52:25.000 --> 00:52:29.000 So a frame coming from this PC right here, 00:52:29.000 --> 00:52:32.000 it's going to come to the phone, and the phone's just going to let it through. 00:52:32.000 --> 00:52:34.000 The phone's not going to do anything to it. 00:52:35.000 --> 00:52:40.000 Folks, is there any VLAN information in here at all? 00:52:40.000 --> 00:52:42.000 Yes or no? 00:52:42.000 --> 00:52:46.000 Is there any VLAN information in there at all? 00:53:05.000 --> 00:53:06.000 Two here. 00:53:06.000 --> 00:53:08.000 One second. 00:53:20.000 --> 00:53:21.000 All right. 00:53:21.000 --> 00:53:22.000 Is everybody back? 00:53:22.000 --> 00:53:24.000 Looks like we had a small little blip in our stream. 00:53:24.000 --> 00:53:25.000 Yeah, yeah. 00:53:25.000 --> 00:53:26.000 Everybody back? 00:53:26.000 --> 00:53:27.000 You good? 00:53:27.000 --> 00:53:28.000 You should be back. 00:53:28.000 --> 00:53:30.000 Yeah, I just noticed that. 00:53:30.000 --> 00:53:33.000 We dropped 196 packets. 00:53:34.000 --> 00:53:36.000 Talking about quality of service, and I dropped 196 packets. 00:53:36.000 --> 00:53:38.000 Look at that. 00:53:55.000 --> 00:53:56.000 Should be good now. 00:54:00.000 --> 00:54:01.000 All right, perfect. 00:54:01.000 --> 00:54:02.000 Excellent. 00:54:02.000 --> 00:54:05.000 All right, so what I was asking here and just saying at this moment in time, 00:54:05.000 --> 00:54:08.000 so we have the traffic that's coming from the PC, 00:54:08.000 --> 00:54:12.000 and the traffic just arrives at the phone, gets sent right through the phone, 00:54:12.000 --> 00:54:15.000 phone doesn't do anything with it, and then it arrives at the switch. 00:54:15.000 --> 00:54:19.000 Is there anything in this frame from the PC, folks, 00:54:19.000 --> 00:54:23.000 that tells the switch which VLAN it belongs to? 00:54:23.000 --> 00:54:26.000 Yes or no? 00:54:26.000 --> 00:54:30.000 This is the frame you would have learned about in your CCNA days. 00:54:30.000 --> 00:54:33.000 We got our source and destination MAC addresses, our type link field, 00:54:33.000 --> 00:54:36.000 our packet, and then our frame check sequence. 00:54:36.000 --> 00:54:38.000 Is there anything there at all? 00:54:41.000 --> 00:54:43.000 Nope, there's nothing. 00:54:43.000 --> 00:54:45.000 Nothing. 00:54:45.000 --> 00:54:50.000 So how does the switch know which VLAN the frame belongs to? 00:55:01.000 --> 00:55:04.000 That you configured it. 00:55:04.000 --> 00:55:08.000 When you configure this command, when you configure this command, 00:55:08.000 --> 00:55:13.000 you are telling the switch if a frame arrives inbound on this interface 00:55:13.000 --> 00:55:19.000 and there is no marking whatsoever, it belongs to VLAN 20. 00:55:20.000 --> 00:55:24.000 Now, Conrad, you are not wrong. 00:55:24.000 --> 00:55:27.000 You are not wrong. 00:55:27.000 --> 00:55:31.000 Because I want you to think of it this way. 00:55:31.000 --> 00:55:38.000 Right now, this is the default VLAN for that interface. 00:55:38.000 --> 00:55:40.000 Think of it that way. 00:55:40.000 --> 00:55:42.000 That is the default. 00:55:42.000 --> 00:55:48.000 If we are not told otherwise, that is the VLAN on that interface. 00:55:48.000 --> 00:55:49.000 There you go. 00:55:49.000 --> 00:55:51.000 See, you weren't technically wrong, Conrad. 00:55:56.000 --> 00:55:59.000 So, yes, Jeffrey, there's no tag here, right? 00:55:59.000 --> 00:56:00.000 There's no tag. 00:56:00.000 --> 00:56:02.000 It is untagged. 00:56:02.000 --> 00:56:07.000 There is nothing about VLAN 20 that is untagged. 00:56:08.000 --> 00:56:09.000 There's no tag. 00:56:09.000 --> 00:56:10.000 It is untagged. 00:56:10.000 --> 00:56:13.000 There is nothing about VLANs in it. 00:56:13.000 --> 00:56:16.000 So as a result of that, you are in VLAN 20. 00:56:16.000 --> 00:56:18.000 You are untagged. 00:56:18.000 --> 00:56:19.000 Nothing. 00:56:19.000 --> 00:56:22.000 Now, let's think about our phones. 00:56:22.000 --> 00:56:26.000 Our phones, when they start up, when they boot up, 00:56:26.000 --> 00:56:29.000 they contact the DHCP server. 00:56:29.000 --> 00:56:33.000 The DHCP server gives them the IP address of, let's say, a TFTP server. 00:56:33.000 --> 00:56:35.000 They reach out to the TFTP server. 00:56:35.000 --> 00:56:38.000 They get their configuration file, and then they configure themselves. 00:56:38.000 --> 00:56:41.000 One of the things they can configure themselves with is what? 00:56:41.000 --> 00:56:47.000 The information that is necessary for tagging its traffic. 00:56:51.000 --> 00:56:56.000 So the phone frame has a tag in it, an 802.1Q tag. 00:56:56.000 --> 00:57:01.000 That's right, the same type of tag we use for trunk links. 00:57:02.000 --> 00:57:04.000 So now, what does that mean? 00:57:04.000 --> 00:57:07.000 Let's pull this out. 00:57:07.000 --> 00:57:12.000 This says 802.1Q tagged. 00:57:12.000 --> 00:57:15.000 This says this would be used for QoS. 00:57:15.000 --> 00:57:17.000 This is our class of service field. 00:57:17.000 --> 00:57:21.000 This would have a value of 5 in it, meaning voice. 00:57:23.000 --> 00:57:27.000 There's the VLAN ID, 200, the phone would put in. 00:57:28.000 --> 00:57:35.000 So does the switch know which VLAN this traffic belongs to now? 00:57:35.000 --> 00:57:36.000 Sure. 00:57:36.000 --> 00:57:39.000 The voice traffic belongs to VLAN 200. 00:57:39.000 --> 00:57:42.000 So if you're tagged with 200, you're in my voice VLAN. 00:57:42.000 --> 00:57:46.000 If you're not tagged, you're in my data VLAN, my access VLAN. 00:57:53.000 --> 00:57:55.000 There you go. 00:57:55.000 --> 00:57:57.000 That's how it works. 00:57:57.000 --> 00:58:01.000 And so now when you configure your QoS values on your switch, 00:58:01.000 --> 00:58:06.000 you'd be configuring that QoS to match the traffic that is coming from the phone's VLAN, 00:58:06.000 --> 00:58:10.000 the phone's subnet, the phone's whatever you're using in your case. 00:58:10.000 --> 00:58:15.000 But now the switch can do what it needs to do based on markings that we can trust the phone now. 00:58:15.000 --> 00:58:16.000 It's part of QoS. 00:58:16.000 --> 00:58:17.000 There you go. 00:58:17.000 --> 00:58:20.000 So more on QoS in a different topic, different discussion. 00:58:20.000 --> 00:58:21.000 This is not about QoS. 00:58:21.000 --> 00:58:24.000 This is about simply understanding how we do our VLANs. 00:58:24.000 --> 00:58:27.000 So at a minimum, you need to know this for the certification exam 00:58:27.000 --> 00:58:32.000 because you never know when this is going to pop up in a question about access VLAN, 00:58:32.000 --> 00:58:35.000 so data traffic, voice VLANs. 00:58:35.000 --> 00:58:39.000 Those are the two most important commands you need to know about VLANs. 00:58:39.000 --> 00:58:42.000 We're going to come back and talk about this command after, 00:58:42.000 --> 00:58:43.000 but I'll give you a heads up on what it does. 00:58:43.000 --> 00:58:53.000 It says, this port can never, ever, ever, ever, ever, ever, ever become a trunk. 00:58:53.000 --> 00:58:55.000 That's what it means. 00:58:55.000 --> 00:59:02.000 Therefore, I can be a member of a single access VLAN and a single voice VLAN. 00:59:02.000 --> 00:59:06.000 Switch port mode access says you can be a member of a single access VLAN 00:59:06.000 --> 00:59:08.000 and a single voice VLAN no more. 00:59:08.000 --> 00:59:09.000 That's it. 00:59:09.000 --> 00:59:10.000 That's all. 00:59:10.000 --> 00:59:19.000 It prevents your port from ever accidentally becoming a trunk. 00:59:19.000 --> 00:59:20.000 And we would never want that. 00:59:20.000 --> 00:59:21.000 That goes down in our phones. 00:59:21.000 --> 00:59:26.000 Now, some of you might be saying, okay, this is different than the way I do it 00:59:26.000 --> 00:59:30.000 on my Cisco switches that I have. 00:59:30.000 --> 00:59:33.000 And it's like, okay, my question to you is, are you using Cisco phones? 00:59:33.000 --> 00:59:35.000 If you're not using Cisco phones, that's why. 00:59:35.000 --> 00:59:41.000 Because there are phones out there that don't work with this type of config. 00:59:41.000 --> 00:59:46.000 And as a result, you would actually be creating a trunk that goes down to the phone. 00:59:46.000 --> 00:59:51.000 So, if you have actual trunks that you created that go down to your phones 00:59:51.000 --> 00:59:55.000 and then down to the phones and PCs, okay, 00:59:55.000 --> 01:00:01.000 it's because the phones don't support this type of config. 01:00:01.000 --> 01:00:04.000 Or you're using a switch, a non-Cisco switch that, again, 01:00:04.000 --> 01:00:07.000 doesn't support this type of config either. 01:00:07.000 --> 01:00:09.000 So, that is a possibility. 01:00:09.000 --> 01:00:11.000 But what is this course about? 01:00:11.000 --> 01:00:14.000 Cisco products, Cisco configs, right? 01:00:14.000 --> 01:00:16.000 That's what you're being tested on. 01:00:16.000 --> 01:00:17.000 That's what you're expected to know. 01:00:17.000 --> 01:00:22.000 So, there's your Cisco way of doing things with Cisco products. 01:00:22.000 --> 01:00:24.000 That's what you're getting ready for. 01:00:24.000 --> 01:00:25.000 All right. 01:00:25.000 --> 01:00:27.000 So, we've already gone through this information. 01:00:27.000 --> 01:00:30.000 We've seen Show VLAN Brief in our live environment. 01:00:30.000 --> 01:00:33.000 We've already taken a look at this output here. 01:00:33.000 --> 01:00:34.000 Beautiful. 01:00:34.000 --> 01:00:37.000 So, that's it for our VLAN discussion, folks. 01:00:37.000 --> 01:00:41.000 We have you covered for what you need to know for VLANs. 01:00:41.000 --> 01:00:42.000 Oh, you know what? 01:00:42.000 --> 01:00:43.000 I want to bring up one more thing. 01:00:43.000 --> 01:00:48.000 I didn't word it as I wanted to, and I realized that after the fact. 01:00:48.000 --> 01:00:50.000 But one final thing just to make sure we're 100% clear. 01:00:50.000 --> 01:00:53.000 If I type in VLAN question mark. 01:00:53.000 --> 01:00:57.000 So, I didn't explain exactly the range of values. 01:00:57.000 --> 01:00:59.000 And I was, like, thinking about it after. 01:00:59.000 --> 01:01:01.000 We need to know the name of the range of values. 01:01:01.000 --> 01:01:07.000 So, for example, if you have 1 to 1,005, okay, 01:01:07.000 --> 01:01:13.000 this is what Cisco calls the normal range VLANs. 01:01:13.000 --> 01:01:21.000 And then you've got 1,006 to 4,095. 01:01:21.000 --> 01:01:32.000 This would be your expanded, expanded, or extended VLANs. 01:01:32.000 --> 01:01:39.000 So, back in the day when Cisco, when 802.1Q did not exist, 01:01:39.000 --> 01:01:44.000 before VLANs were a standard, Cisco supported this many VLANs. 01:01:44.000 --> 01:01:47.000 They had their own trunking protocol called ISL. 01:01:47.000 --> 01:01:49.000 They were using VTP and different things like that. 01:01:49.000 --> 01:01:51.000 That's where all that came into play. 01:01:51.000 --> 01:01:55.000 But then once 802.1Q was invented, 01:01:55.000 --> 01:01:58.000 then they had to expand to support all of that. 01:01:58.000 --> 01:02:05.000 So, the reason why we have these two different names, 01:02:05.000 --> 01:02:07.000 so if they talk about normal VLANs, that's what they mean. 01:02:07.000 --> 01:02:09.000 If they're talking about expanded or extended, 01:02:09.000 --> 01:02:11.000 they're talking about those ones. 01:02:11.000 --> 01:02:14.000 They had to expand out their range because of what? 01:02:15.000 --> 01:02:18.000 The invention of 802.1Q and VLANs, 01:02:18.000 --> 01:02:22.000 and 802.1Q becoming a standard throughout the entire industry. 01:02:22.000 --> 01:02:23.000 That's why they did that. 01:02:23.000 --> 01:02:26.000 So, I just wanted to make sure you had those numbering schemes in place 01:02:26.000 --> 01:02:28.000 that go along with our discussion. 01:02:28.000 --> 01:02:30.000 I failed to mention that just in case, because on the exam, 01:02:30.000 --> 01:02:34.000 if they use those words instead of actual numbers, 01:02:34.000 --> 01:02:36.000 or they throw those words out there, I'd hate you to miss a question 01:02:36.000 --> 01:02:39.000 just because you didn't know the word that goes along with it. 01:02:39.000 --> 01:02:41.000 All right, there you go, folks. 01:02:44.000 --> 01:02:45.000 Thank you.