DO NOT design your network like this!! // FREE CCNA // EP 6

Hey, I have a question for you: can

your

network

survive a pug? Well, what about a baby? If you can't afford to lose a link, a switch or a router. You are doing it wrong in

this

video. I'm going to show you two

network

architectures that can help make our networks awesome and a big shout out to boson software, they are the official sponsor of

this

free

ccna

series and if you're trying to get

your

ccna

, I guess it's probably a lot of You Boson have the best lab practice exams and now the best teaching materials you can find for the ccna.

In fact, I'm giving away three copies of their teaching materials and labs at the link below, so enter the contest that ends tomorrow, Friday, so hurry up. Now, before I show you what a good network

design

looks like, just a beautiful and delicious one, let me show you a bad one first. As you work to become a network engineer, you will see some bad networks and it is your job to identify them. why they are bad and how you can improve them Now to find a bad network you don't have to look far look around your house I'm not kidding your home network sucks no I know many of you probably have an amazing home network comment below what you have, but for many of you, if you had a business from home and you used that home network, it would just die, your business would be dead now I say this because many companies when they first started, their network looks a lot like a home network and they make big mistakes, some very big mistakes, let me show you what that would look like, so Network Chuck Coffee is still a very young growing small coffee company and let's say I trusted a newbie to install my network, I would never do that, but Let's say I did it very similar to your home network.

I will have a router, although in your home network your router is not just your router, it is also your switch, your modem, even your website, no. It's not the song, a wireless access point, this is a networking video. Get it, so he's doing a lot of things, which is a horrible thing. You don't want to have one device doing everything and we'll see why that's important here in a For now, but for now my coffee business just has the router and my router connects to a switch and honestly for a small business this is good.

I have my computers connected to my switch. I will have a wap and the wireless access point connected. as well as giving all my people wifi, maybe some phones and then of course my server to run my website. Wait a second. My switch only has 24 ports. I ran out of ports. I have more things to connect more computers. more servers, what do I do when I tell my new network engineer to fix it for me? This is where the newbie really goes wrong. What does it do well? Get another switch. Alright. He does a great job of getting it done.

Here it comes and then you plug the switch into the switch and then oh wait, what did you do? What did you do? This is bad. I'll explain why here in a moment and before long I'm growing. I'm going crazy so I need to add another one. switch, so my new network engineer makes another switch and adds it here and then does it again, connects the switch to that switch, I'm sure many of you, if you know networking, that's probably scaring you, it makes me I just have heart palpitations just thinking about it this is bad now it works don't get me wrong this totally works but then this happens my pug moses comes over and starts chewing on this wire right here and all of a sudden the wire breaks and then what happens ?

Everything's good. the device is connected to the switch and this switch is gone, they can't connect to anything, they are down, this is what we call now, say it with me, a single point of failure, never have them on your network. All of these here are single points of failure, which basically means that if one thing fails, most of your things fail. You'll never want to have that now again, this

design

still works. You may have something like this in your home. There are many. businesses that have this and it works most of the time until something breaks in your house, you can afford to have it fail because the worst that can happen is you miss an episode of Netflix or worse yet, you can't watch my next video, but in business that means dollars and cents, that's money time now I'm showing you this because you're going to see this in nature in the real world and you have to tell them why it's dumb and you have to fix it so how do we fix this?

Are we doing it well? Some might think well, you know, we have those single points of failure. Let's just add another connection. We could do that. Add another cable here. Another cable here. That's better, but what happens if the switch goes off? Where is this switch turned off? We still have glaring issues and this is not ideal, so we have two designs that we are going to talk about today, they will help us be redundant and you will hear that word a lot when you talk about the network design that you want to eliminate. as many single points of failure as possible so you want to be able to have a wire down but things are still up a switch goes down but things are still up let me show you what that looks like so daisy chaining our switches together is bad don't do that, so what do we do, how can we improve this?

Well, we could do this, let's put the router right here and instead of daisy chaining, we just connect our switches to the router, each one done, that was easy, come on, chuck. You're making it sound very difficult. Well, we're not done yet. This will work, but it is not ideal. For example, my computers work great when they want to access the Internet because that's what the router is great for. for layer three but my computers and my servers not only communicate with the Internet, they communicate with each other, they communicate on the same network and that is where the router becomes less ideal and is not the best for the job, so , What we want? it's another switch but not just any switch oh you're going to love this this is something that when I discovered this I was blown away so let's bring the router here for a moment he's still in play but we're Let's talk about something else here.

Let's get this guy right here. What is it? It's a switch, but it's not just any switch. This, my friends, is a multi-layer switch often referred to as a layer 3 switch, which may sound strange if you've seen my previous videos. We know that switches deal with Layer 2 Mac addresses and routers deal with Layer 3 IP addresses. What is a Layer 3 switch doing here? That's science fiction, it's weird, I can't deal with it, no, it's unbelievable. literally a switch that can handle IP addresses and Mac addresses, it can do it all and it's incredibly fast and then our multilayer switch will connect to our router and we're looking a little better right now, aren't we? really beautiful if this connection goes down or this switch goes down then these two are still up this computer is still up this server is still up it's better right? and I'm sure you're thinking, well, chuck, we still have this right here, this single point of failure, yeah, we'll get to that, we're taking baby steps and you'll find this a lot when designing networks for enterprises because designing a network with points Limited single points of failure can be incredibly expensive the more devices you add, the more the bill increases, so I'll show you how we can fix this single point of failure here in a moment, but know that the more we add, the more it will cost.

You will have to work with the company and what their budget is now for this architecture. This model here, the way we design our network is called two-tier architecture. Let me show you the levels right now. Here is level number one and level number two. The switches at this level one are called access switches and we'll do that. Call this layer our access layer because they give our devices the things that we connect to our switches, you know, my cables hold things like Raspberry Pi that gives them access, ooh, that sound, let me add a pie there real quick, I can't not have a raspberry pie cake in my network here, what am I crazy?

We're doing much better and then our level two layer, this guy is called our distribution layer and of course this would be our distribution switch, why is it called that? because their job is to distribute. all the packets all the frames across the network like it's it, everything goes through it if the computer wants to talk to my server, the computer goes to the distribution switch, it goes down to access, it goes down to the server if it wants to access to access the Internet, switch to the distribution switch. router now because everything goes through it it has to be quite bulky it has to be it has to be big now what do I mean by that?

Well, think about computers, this Raspberry Pi, although it's amazing, it's not like a computing powerhouse, it's small, you're not going to do it. be playing call of duty with this guy, well not yet, you never know it's not powerful enough and the same goes for switches, if you have a small eight port switch it can only handle a limited amount of traffic before say: I need help, so don't do it. Don't put a small eight port switch and your distribution layer will die, so at the distribution layer you'll want a huge switch with a lot of power and just like a computer, you'll have more components, more expensive hardware to do it. faster, now I have shown you access layer switches, it is something like this, but distribution layer switches are another beast.

Emphasis on beast, let me show you one real quick. Here is a list of Cisco switches that could be considered distribution layer switches. I have options and it all depends on what you need and how much you can spend, so here we have the Cisco Catalyst 3850. They have a very similar form factor to the spindle layer switches, but they can handle a lot more things, as you see here. 480 gigabits per second on their backplane, which means they can handle as much traffic passing through them at once, which is a lot, but of course if you need more, you can get more.

Go to the Cisco Catalyst 6500, it's got 11.4 terabytes per second or terabits per second and look at that thing that's crazy look at that guy and we'll cover more on these guys here in a moment because they can grow and they have a different role, we'll touch on that. here in a moment We haven't gone too far down the Cisco rabbit hole yet, we won't worry, so I glossed over what the distribution layer is responsible for. It does more than just distribute, like we took a field trip to boson educational software. real quick, you're going to want to get this.

I have your courseware open now, let's learn about the distribution here. Real quick, if you want to get this, I have a link below. I didn't mention this before, but the distribution layer is. sometimes called the aggregation layer, let me highlight that that is the worst highlighter, always better, okay, but it does things like route filtering, entering VLAN routing management, ACL security policies, IPS, routing because remember they are the layer 3 and then the summary and redundancy of the next jump. There are a lot of words that we haven't covered yet, we'll just know that those are the roles that the distribution layer typically has or what we give it.

Now there's something I skipped. You may have noticed this because the distribution layer is the intermediary between the backbone layer and the core layer, which is the core layer? I didn't talk about the central layer. Well, hmm, if I scroll up a little bit, look at this, there's another layer, what is it? We'll talk about that, right? Now we're just looking at the distribution layer and the hub layer, which is called two-tier architecture and again we'll touch on it here in a moment. Now let's talk about these other single points of failure, how can we fix it?

Well, we can add more devices, like look at this. I can add one more distribution layer switch. Let me do that. Move it here and we'll connect our switches so it looks like this. We will add one more connection. one more connection, one more connection, then of course we'll connect our switch to the router and then we'll even connect our two switches together. This is what I'm talking about, we have two distribution layer switches, no longer a single point of failure, we have two links to each switch, that's awesome and then we have two connections to our router, but wait, we still have a router that we can solve, let's solve it right now, let's put one more router and we will connect. both switches, man, look at all that redundancy, it's beautiful but expensive, this is ideal.

A lot of companies aren't willing to pay that much for things because, I mean, oh my gosh, these layer three switches could be like hundreds of thousands. of dollars the same for routers, depending on how big you are, no one said networking is cheap, that's why we make a lot of money now. This two-level architecture is not the only one on the block and let me show you where there is a three-level architecture.levels could come into play, let's say the closed network cafe really starts to grow like oh my gosh and we have to add more buildings just to house all our people, we have so many people now we have three buildings, things are booming, it's amazing, but I need to connect our buildings together so we can all have a network, that's what we're doing here, okay, let's connect them, so I'll connect my multilayer switch to my multilayer switch down here, my layer distribution is the same.

Let's go here and do it here, just random, but hey, we have the right connectivity, but let's make sure we add some redundancy, we'll also add redundant links, we'll make sure that each switch has a connection to each switch and that each location has a connect every location is fine, we did itIt's a mess, but we did it. We have another building on the way. Okay, get ready guys, I have to hire more network engineers, so let's get them connected. Here we go, okay, this is getting a little crazy with how big our distribution switches are.

They're under fire right now They can't handle all this Too many connections They're running out of ports We're maximizing bandwidth What do we do Let's go with a three-tier architecture You saw that coming, come on Get all those connections out of there? Wow, it stresses me out. We're going to add one more layer here, so let's get our routers out of here or lift them up. We are not going to get rid of them and we will put in our next layer and this layer will have a beast of a switch, it will also be a layer 3 switch, but this will be the big daddy, it will be so powerful, so incredible that it will be able to handle all that traffic, this switch is our main switch and This is our level 3 core layer.

Our distribution layer switches will connect to it. In a perfect world, we would have two of our cores because he is the main one and we connect them and our cores will be connected to each other. and then we'll connect our routers to our core switches. This is a beautiful and charming campus network design. Oh, very good, expensive but good. Well, what does this core layer do besides being awesome, powerful, and huge? Let me show you, let's look at the boson. so the access layer we know is connecting our devices are our phones our computers all of it is the access layer distribution that we just talked about now the core layer what is it doing look how short your paragraph is that really sums it up here It's like that huge guy in the gym over there, oh there's grunting, that's all he does is grunt and lift, that's what this guy does, it's just fast and it's associated with low latency and high reliability, so that the central switch is expensive, reliable and robust because it is the backbone and a lot of traffic passes through it, it has to be able to handle a lot of the weight of the network on its shoulders, so this is our central distribution access of Cisco's three-tier network design model.

Now I want to talk real quick about on the two levels, on the two levels, the core layer was gone, but no, no, wait, he wasn't gone, he was still there or his function was still there, that became the distribution layer work. Let me show you a quick scroll down. the amazing boson courseware and access Cisco's two-tier network design model. Notice how they call it the collapsed core layer. This model is often referred to as a collapsed core model. I don't know what happened to my id there, just ignore it, but The kernel functions were collapsed to the distribution layer, so the distribution switches have all the responsibilities of the distribution switches.

They have to do a lot of routing, routing access control lists between VLANs and things like that, they did a lot and then they also have to be the backbone of the network, they have to be powerful and crazy, which in most the cases are fine. I have seen more collapsed core or two-tier models than three-tier ones. Fantastic for what I'm about to show you now, looking back at our four buildings. Here is our new design with a level three. Notice that only one of the buildings has the center layer, the level three layer, and that is the design, right on the center layer. is the core of the entire campus, so now you can imagine how this could simplify things: our distribution layers will connect back to our core layers, but only to the core layers, not to each other with that nasty mesh like we had before, this allows us to scale much easier if we have a huge campus, so this is a little better.

My drawings are horrible. Let me show you a better view from Cisco's perspective. Cisco has excellent documentation. Here's how buildings will connect without a core. We just saw this. mess, it's not scalable, it's too complex, but if you scroll down a little bit, here's our core and it solves a problem, it's beautiful, much cleaner, we have our one core and then we have all our level one and two and our buildings. now you want to look at a core switch and how big it might be looking back at the distribution available from Cisco and of course, which is what it's called, find the best core and distribution switch for you, if you're on the far right, It's the smallest things. you go to the far left you get bigger and bigger until you get to the big daddy, the Cisco Catalyst 9600 series, this thing is a beast, they are modular so you can slide in little extra features and the wonders they have are redundant. everything and look at the available backplane or the bandwidth, it's 25.6 terabits per second, it's pretty crazy if you want to see one of these, actually David Bomble and I went to the Cisco headquarters in San Jose and we were able to talk to the guys who designed it.

They walked us through it, so I have a video below, if you want to watch it, I'll actually play a clip right now, man, and that's also another future test for delivering power. They had just released it, they let us take a look at it. and play with it like crazy now, as I mentioned before, this model here is the one I've seen the most, it's the one I've worked with the most, the collapse core, where you have your access layer doing its job on both sets of uh , designs, but then you have your collapsed core, the distribution switches are also the core switches and then these switches will connect to your routers when we look at level three.

I love looking at that Cisco example. This is why you want to have a level three when you have a bunch of buildings on a campus that need a high speed connection to each other as if they were all in the same building, so we call it a campus and really where do we get the term is like a university campus a school campus I went to the Cisco campus and they have like a billion buildings. I got lost several times and they have things like this. I mean, they invented it well, so they invented it because they probably needed it, but what I found like most companies.

I've worked for us, we have a main corporate office and we had our main distribution switches connected to our access switches and that's all we needed now, that's just the campus that connects our people and our users in the same building, although we have more than that. we also have data centers and how we design our data centers we have the cloud and how we design our connections to the cloud we have our wan we have our small office home office we have our users all kinds of different things we're going to talk about everyone who will be here in the next episodes now i have some homework for you this is what i want you to do most of you work for a company right you might be in your IT department you might not be in your IT department .

No matter what I want you to do is find out what design they have. Is it two levels? Is it three levels? Is it some strange level? Don't know. Find out and let us know in the comments below. I think so. It would be so fun to see everyone's layout and their network and that was episode six let me know what you think comment below if you have any questions or just suggestions let me know or if you need any help let me know too and by the way. Did you know that I have a Discord community?

Discord is a place where you can go and get help. I have about 14,000 people there right now willing to help you with whatever you're doing. Looking for a job. I need help with ccna. I have the link below to join and did you know I'm on social media? Are you following me on Instagram, Twitter, Facebook, LinkedIn everywhere? Well, I am, so follow me. Everything is Networkchuck on Networkchuck. I post there sometimes, so follow me sometimes. you want to help me do more of this by creating

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training on youtube by creating low cost courses and other places where you can join my membership become part of the team you can join via youtube with the join button below or sign up but this that's all. .io, I have links below for everything or my patreon.

I also have a patreon. Oh, and don't forget to enter the bozon contest. I'm giving away three copies of his netsim for ccna and his new courseware for ccna, and it's amazing. So the contest will end soon, so you better hurry up if you are too late and didn't win, don't worry, I have a special link below, you get 15 off, so check it out, tell them I sent you, it will help you a lot. when you buy their stuff through my links, okay yeah that's all I got, I'll see you guys later