Root Bridges Lab

33 minutes
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Alright, Welcome back, everybody. Now, we're going to be doing the rest of this section in the lab. So you get a better understanding than just me telling you all the different things. Because it is basically the same thing that we've learned previously for the CCNA. There's added a couple more things, but I wanted to create a different type of network not just to be switches or what have you. So as you can see here, you have the Cisco three layer model, you have your core, you have your distribution, and you have your access switches.

Okay. Oh, by default, one of the things that we talked about, we mentioned previously was asperity is great because battery does everything by itself. There's really nothing you need to do. Supposedly, right. There's nothing you really need to do. It does it all by itself, but can cause some problems, because it could happen that the root bridge could be the one that is the like, that's your slowest switch.

That's not your best, you know, the CPU can't handle all the messaging going through it all bpdu. So I may not be the switch you want to be. So you need to decide who's going to be your root bridge. And as you can see by the lab, that apology we have here that the top which is the primary root bridge, and one new thing that you're learning now is to create a secondary bridge. That way the one root bridge fails, the old will take over, and they put their own priority numbers when that is done. And that is done because by default, it should be 32 769.

Now I know All you've read in all your books that it says 32 768. And yes, if you were to look at the number, okay? That you would choose, let's say to do a manually 32 768 is that number, but it adds one for VLAN one. So this is our one, it becomes 32 769. Because it'll always add the VLAN ID to the priority number. And that's how you get.

And that's how you get it you can put when we do it, now you'll see it spanning tree, you know, on priority number zero, which is the lowest one. Well yet when you look at the show spanning tree command, you're going to see that it says party number one, because they're out of one for VLAN. So yeah, it's 32 768 buses you out one, two, it's 32 769. All you need to keep in mind is that the lower the number, that's the one that's going to become the rich by default and But that's the problem. And that's the problem of all party numbers are the same, then you know, I looked for the lowest MAC address, and again, that it could become an issue. So you, you decide who you want to who you want the root bridge to be.

And you could neither pirate tracer, but you could in real life, put cost values, on the lines on the ports. I say lines, I was thinking about servers and stuff like that, but on on the actual ports, also, you can determine which way because let's say right now, you see this is blocked, so this is not gonna afford anything. And this is not gonna afford anything. Okay? So let's say you want to get over here to the root bridge. So the way it's gonna go, it could go this way could go straight up that way because that is not it's blocked for 40 but not for listening, or may go this way.

But you can determine which way You want to send it by using the spanning tree, path cost VLAN path cost or Command, you can do that. You can do that. Okay, so I do have a notepad for the monitoring of spanning tree. But let's take a look at what we have so far. So this guy here, this guy here is blocked. So these, if he's facing that way, that can be the root bridge.

Right? And let's verify that this cannot be the root bridge, because there's a block port facing it. So let's see if my theory is correct show spanning tree and older more ago, these crunched up in there and that is not the rubric. It is not. So the root bridge is this guy, because he has no ports that are blocked facing him. Okay, so this will be a report.

This would be a root port. This would be a report. And this would be a report for all ports facing the root bridge our reports, let's take a look and we're going to just figure that out just by looking at the ports on the switch we were just on. Alright, and that shows spanning tree. And you say, Hey, this is the root bridge. Okay?

0033 E four a D, zero, C, zero. So this must have the lowest MAC address because outside chooses it, the lowest MAC address. So this becomes the central hub. This becomes the where all other switches want to get to, to get information because that's where information is coming from. Okay, so to get to the root bridge, how quickly they need to get there. So this is all fast.

The Internet says 19, zero 19 and 19. That's 38. Okay, if you go 19 1919 now it'll be too much. Okay, so that's the reason Alright, they you can say, okay, which way do I want to send it? You can have you have that capability of putting path costs on individual ports right now here in the packet tracer, but in real world, you can do that. Don't go crazy.

Don't go crazy. Okay? The main thing is saying, okay, who's gonna be my primary bridge? And who's going to be my secondary and the only reason again, reiterate what I said before. The reason you have a secondary root bridge is for backup purposes. Only if that root bridge on the top was we're going to make it one.

Okay, decide, hey, I am I failed, my links failed, then that's it, my CPU died, whatever. Okay, I got hacked, I don't know. Then this guy will take over as the root bridge because you are going to set it as Such. Okay, so let's take a look at those guy. And we're going to take a look at his priority number right now, which should be 32 769. Again, let's see we're getting like arrange this a little bit here, since you're gonna be working with basically the top switches the layer three switches the core and distribution.

Won't you be able to see everything? Not crunched over nothing. Okay, here we go. So let's give this a name. First of all, so we know where the heck we're at Paul's name. We'll just call it core caps.

Caps or config T. Come on that was name. Core. All right. So let's do a show spanning tree just to see the default going really shows boundary. Do shows boundary so bad My gaming thinking about a game design do show spanning tree. This is what Todd does.

So you forgot to spell do show spanning tree. Okay? And you see there's 32 769 that's what I was talking about earlier you see here says 3768 flaws, the system ID extension which is wrong, which is VLAN one, therefore, it adds it to 32 768. So after you get 32 769 even though the books are 32 768 No, no, no, no. is 32 769. Okay.

All right. So we're going to make this guy the root bridge, the primary root bridge in the CCNA. You didn't do this. You're going to do this now. So we're going to go spanning tree VLAN and it will surely create these VLANs one comma 10 comma 20. Across all these VLANs prior priority routes, okay, and we're going to say that there's going to be primary.

Okay, you see things start changing you see the lights are going Amber. All right, that's gonna be my primary root bridge. Okay, and this guy over here at hostname. This isn't the distribution layer. We'll call him DS to be as to distribution switch to. Alright we're gonna do spanning tree VLAN one comma 10 comma 20 and then we'll do all root and then is a year second Okay, question mark.

All right. So if you know how to spell second, they're speaking to myself. Alright. So now these two are now set up. Now you can see the top layer three switch, no longer has a blocked port. Okay?

Now this guy has a blocked port. How about that? So that cannot be the root bridge. So if we were to do a show spanning tree, you see that he is not the root bridge any longer, but take a look at the priority number. It's 24 577. It said that it said that at all.

And it's not following what I certainly would have said 28 6721 whatever that's so it sets its own priority number based on the command that I just typed. Right. Now let's take a look at this guy which was in the rubric. Number. So we do do a do show spanning tree again do show spanning my spelling tree. Now this is the root bridge.

Well look how funny it's the same number. It's the same exact number, or zone, while 24 577. That's always a hard number to forget. It's 24 577. And this is a rubric because it's the primary root bridge. Okay?

And if we take a look at this guy, he is 24 577 as well, what is the secondary? He's a secondary. Okay, so he's the backup. So, that's how that is done. Okay, that's all that is done. not difficult at all.

You're usually doing VLAN priority, you know, being on whatever priority and you put a priority number Now you're actually putting primary or secondary, because everybody puts just a primary one root bridge across a whole entire network. That better be a hefty switch that can handle loads and loads of traffic. There won't be burden. Okay? But in case you always want to have something to fall back on, and that is your secondary root bridge. All righty.

Now one of the things that we're going to do as well as we want to change the spanning tree, okay, what's going on? backspace is not working. Oh, ah, it's changed them over if you do, show start. Okay, they'll be our show start. Okay. When you go down you know, your though says spanning tree mode PVS T. We want to change that to rapid p vs T. All right, we're going to do it to all the switches, one with all the switches.

So we just made, we decided that that root bridge on the top is my main root bridge, that is the man that can handle anything. Okay? So that's what we want a hand and the one to the right do is to, okay is the actual secondary. Alright, so let's start from the top Ctrl Z. And let's do that config See what I did. All right, spanning tree mode.

And here are the different modes. So we're gonna do rapid spanning tree. All right, do wr shift six. Really? Thank you. Alright, we'll go to this guy.

We haven't been in here yet. Well, we have a really good Things electron has got a human name. Last Name d s one both This is why tab is fatal for me DS one. All right, and then we're going to change his spanning tree mode spanning tree mode. Rapid p vs T. Okay, do wr go to our DS to same thing spanning tree mode, rapid p vs T. There we are. And even in your access layer switches.

You want to do that as well. You want to do that as well. Okay. Enable, I think spanning tree mode, rapid pbmc I said, you want to make those backward compatible, make sure you're in the same versioning because one of the things is, like backbone fast and uplink fast. They're both pretty much the same thing just to make the lines come back up and make them quicker, just like fast combat any, you can't, yeah, I'll blink fast. You could have walk forwards, but backbone fast you can have any by any any block ports I believe is that or vice versa.

I forget sometimes, okay. But that's basically it. But those those are legacy commands really well, they're newer algorithms of SDP that takes care of the convergence, when online goes down or how quickly they converge and come back up. So that's really I mean, just know that that's what they're there for. You know, you could make it go faster. From now on when it goes down to come back up.

That's a no requirement is one can black box Lock ports your one cat. That's it. That's it. All right. So keep everything the same though. Naval, conflicting spanning tree rapid about mode, right?

Robin pbmc dw and which switches This is the middle switch styles HR. I think this is gonna give this whole thing of accounting was what I thought all the lab knew that's what I was gonna make these particular VLANs that's now that we're going to make any PCs are going to be anything like that, because the main purpose of this section is basically showing you how to change the mode or the root bridge, the placement was or the most important part of the root bridge and then just showing you different commands like we do here, the mode and the primary and the secondary things that I nature and how you want Look at all these different things. How do you How would you look at us? All right. Over here last switch, I believe should be registrar. Enable from 15 or name.

Register, just try. Okay. And then we'll do spanning tree mode. Rapid PST. So now we're running the newest version along PVS t, which is cool, because now things will converge quicker. You can have multiple instances of the spanning tree.

Even though we didn't do it here. We're doing array across all VLANs okay 1020 and there should be VLAN 30 as well. So I don't know why they didn't do that. directly in the VLANs encrypted Oh, See, for the VLANs that are just example 1020 whatever. No, actually, when we change the spanning tree to say the on 110 and 20 minutes because I do yes I do. Yes I did.

Well, well very easy to monitor that. It was go to a global configuration and do a show spanning tree. All right, I can see here we have two reports. This one, we have root port, which is zero 22, which is this one. And we also the rest of them are designated designated 40 and one block port, one block port. Alright, so as you can say, okay, there's gonna be a report to what about this one, there's gonna be visiting there 40 pretty much I think it's going to do that.

That's we do show spanning tree. And these are things you can see there's only one root port, which is 23. Again, facing the root bridge, and then these are designated 40. And to get to the root bridge, it has to be the fastest way. And that's based on the cost or the particular length. In this case, everything is 19.

So like I said, if you were this guy, you now this is the root bridge. Well, hey, 1919 is 38. Okay, I'm not going to go this way. I'm not going to go this way, this way, this way. I mean, you could if you wanted to, for whatever reason, but things you chose this way, it's new, this will mean hey, this, which is the fastest switch, and if you think this is the secondary, this is the second fastest switch. So this may not be the maybe this may not be the best route even though it has the lowest cost path right?

In 19, maybe a nice to go 19 and 19. And then 19 going this way, this may be the fastest way not necessarily Does it mean that a straight line is the fastest way, you can run into the switch and this switch is so burden, they can say, Man, I can send you any fashion that I'm sending you now. So it can be you get a very, very slow bpdu, inferior bpdu. And then it'll send you out this way as well, in this case, it can't send you out because it's blocked. It could send you out this way. And then you can go this way, but that would be 19 1919, and then 19 again.

So you really got to think about it, how you want to do that, how you want to do that. That's why I'm saying that the placement of the rubber is not necessarily I put it up here, but this is just to give you a visualization that the root bridge is king is the centralized hub of everything. And I just decided to pick the one on the right as because they're all the things which are the same The one on the right. That's a secondary one. bridge one just to show you the commands into this, I just chose it. All right, I could have chosen this guy or I could have chosen one of these axes lives, we should never would do it in a real world.

You want to keep everything pretty much in your access layer, even though whatever VLANs are creating. And again, remember well in previous sessions we talked about end to end VLANs and local VLANs you can create local VLANs that will never leave here meaning you can create an actual VLAN just here that will never go anywhere else. Okay. And although your local VLAN here a local VLAN here, but not all switches need to know about it. This is where your VTP comes in and the trunking and all these different things. But again, the purpose of this session is configuring spanning tree and we have and we have we saw the default was we went ahead and said the root bridge, the secondary root bridge, we change spanning tree to the PVS tee and then the show commands show spanning tree that we can do our very, very simple basic commands here show spanning tree with a summary.

Okay VLAN one, which is the only one I'm creating on the VLANs. Okay, non blocking and which is true. Okay right now nothing is going on so they're listening. They're not doing anything. Okay, there's no i piece will be campaign. Alright.

But or you can do let's do show spanning tree and let's expand this a little bit all right so we can see detail and then we'll give you the details of it. All this has been on one we're executing the rstp compatible Spanning Tree Protocol, the bridge identifier, hey 28 six, okay, there's the one MAC address, configured the timer on it. Okay, oh 4101 here's the path cost, I mean, so it gives you a lot of information which is nice, you know MAC addresses, priority numbers, all these different things that you would need to know. Okay? But again, there's a lot of here is just a very few commands. You will also say interface F Zero slash one.

Alright, and there shows you that V 901 causes before designating Port 19. Alright, so which 1am I in I'm in the stew. So let's look at Port 23. Okay for 23 that is been enrolled status here is a route or this one. The first one we did it was just affording doesn't get affording is is a route All right, and the calls is still the same. That calls us to this thing.

Okay? So these are things you can do to monitor your spanning tree. And definitely, if you're running the latest spanning tree, you can do an instance, I want to say an instance when you're creating, let's say, here in the root bridge. And let's open this up. It goes normally what we're used to doing is saying, spanning tree VLAN 10. priority and a number. Right?

We didn't do that. We didn't do that. We did. It was one time 20 and then route primary. So but we can do the same VLAN 30. Now we're going to create or what have you, and we can say priority T and we can set it at let's make a mistake.

Isn't saying hey, you can only set it at these particular ones. It gives you the one that we have set for the root bridge and a secondary bridge is 24 577 here you see 24 576 so it does follow adds one and then gives it 24 577 There you go. So my philosophy is true. So what we do instead of giving it 24 577 let's say we give it Oh 36 860-430-6864 talk. I take the whole thing 36 864 Oh my god. Okay, think 64 There we go.

So you did it for that one. So now I'm not gonna have that's another instance of spanning tree so if you were to do show, spanning tree or right you see Villa one method okay sure. Spanning Tree VLAN 10 device X has been created with or created let's see. Let's create it VLAN VLAN 10 name we'll call it dear okay you're very hard we're not gonna assign it to any poor time delay that. So now let's do the commando you want it to do do show spanning tree shows by show spanning tree VLAN 10 spanning tree exists. Okay.

So there's no nothing assigned to VLAN 10. So that's why it's giving you this particular message. We're literally need to assign these to the intent and do the VTP trunking and all that good stuff for that to happen but You could like I just did up there did a spanning tree instance just for VLAN 10. All right, or or you can do it for all the VLANs is completely completely up to you how you want to do it. Okay? To me honestly, being in schools are very long time and doing their it as well helping out with it as well.

I just do all do their priority depending on the school do the priority, or I'll do the primary route. But more likely, I will probably be doing the priority. And I will do it for all our VLANs all our VLANs but the problem is that schools, the one that I've been with, don't create the events. Now one minute, but they have no redundancy either. And that's the problem. You can't really have a good network, without redundancy put into this with In one link, you have a switch in the classroom and then have one wire going back to the rack which is connected to that particular patch panel.

And if on the patch panel and goes to whatever switch and then from the switch obviously to the router. But if that one wire going from the classroom back to the rack, you know you got gives you the mouse the decides to eat through it. All people in that classroom, whether it be 15 3020 harmony nodes in the classroom, my classroom is completely down period. They can't network at all. Well, they can go into the internet, let's say that they have no internet connectivity. They can network within their own classroom.

That's it. That's all we can do. But That's why we mean by redundancy. Now there is such a thing as too much redundancy. And again, this is where spanning tree comes in. If you have 20 million switches, do not worry about oh my god, I got two redundant three redundant four redundant links over here.

I'm going to go ahead and let me calculate the path cop. No, don't worry about that. That's what spanning tree is. Therefore, you concern yourself with the placement of that root bridge. And then that will take care of itself. And the decision that you're going to say, Okay, this is my beefiest, which this is the hardcore switch.

This is the one that's going to be the root bridge and the second hardcore is going to be the secondary just in case something happens. Okay, just in case something happens. And obviously, they're going to be part of your either your distribution or your aunt or aunt or your core layers. They will never Be your access layer should not be your access layer switches, okay should not be your active switches. Well, that's it. That's what this session is trying to tell you.

Okay? Not only those monitoring commands that I just showed you right now, but how to create the root bridge manually. Don't let the default take care of it. And then how to choose a secondary rubric, slightly different commands, as you saw. All right. And that's it.

That's really all there is to it. And just make sure and that you can also manipulate sorry, also you can manipulate the path cost. All right, by getting the packet tracer. We can't do that. There's no command for that. So but you can go into an interface.

And I'll just show you before we finish this interface, F Zero, where am I? I mean, the core is 01. Which I did inferences on. You can Calm down. Okay, and then you can do spanning tree from in here, as you can see right here. Okay, in the spanning tree.

All right. And again, we know what portfast does. Okay, we know what portfast does, we can go ahead and say turn off Spanish altogether, which we don't want to do, obviously, not at this level. Okay? Our guard just changes into the top of guard mode. Okay, this is a layer three switches and I like the other switches inside the safeguard mode to the root on that particular interface, but there is no path.

Now we can go ahead and do there is no path. Okay? We can do VLAN and then we're gonna say VLAN 10, which doesn't even exist and they can set a port price. Already a port priority. Not a path cost. I guess it's a greatest line, but it's not the same thing.

It's not the same thing. So again, what are you trying to go to? Here's what I just told you. All right, the placement of the root bridge the primary route bridge, the placement of the secondary root bridge, before switches Don't let its boundary decide by itself, change it to the latest version, all your switches have spanning tree, okay? And let the rest take care of itself with the rest a carousel unless for whatever reason you want real world that you want to change the path cost we can by going inside the interface into the spanning tree VLAN path cost command, you can do a path cost. Okay?

But that's it. That's all it is. It really is not a big deal. Big deal. And you're swayed in your certification, they're more likely will ask you questions are the primary rubric and the secondary rubric. But to do all a lab even better, because it's really not that elaborate but, but let's say like this, now be a little bit much, you have anything you have maybe four switches in a in a printscreen type of scenario, and you will decide who will be worn and things of that nature.

And they ask you to select the command, which I think it would be multiple choice as well I don't know. Or it could be a scenario, an actual lab environment. But again, you have, you're limited to the time that you're limited to. So I don't think they'll be playing around too much with that. Know your ports. Okay, but we'll talk all about that in the summary coming up.

I'll see you then.

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