Clients, Servers, and Protocols | Cisco CCNA 200-301

[Music] and welcome everybody I may go ahead and dial in my screens here hey it is great to have you thank you for joining me for CCNA Sunday all things CCNA and our objectives what we're gonna do is I've laid out a an outline for the next probably couple three months of topics I'd like to cover from CCNA cisco certified network associate and I'm gonna cherry-pick a little bit and kind of create the content that I wish that someone had created for me almost two-and-a-half decades ago as I began to learn Cisco and started getting involved with it so our objectives are these right here pretty straightforward let me go ahead and hide this one layer as I talk through this way through our objectives are for us at the end of our short time together today I would love us either one of us both of us to be able to describe what is a client or a server if sorry so say says that we can say oh I know exactly what that means and how that fits what is the benefit of a layer or what even is a layer and then what is a protocol stack so that's our objectives we'll come back at the end of the stream and we'll confirm that we are all comfortable with those topics and we're gonna build one logical piece at a time all right so let's go to this network and let me bring out a little pen so I can annotate some of this and they bring that up there it is and this is a pen that allows me to write on the top of everything which is just absolutely wonderful all right so let's start off with the concept of and it's this is a lot like just going into a restaurant let's talk about that for just a moment regarding servers and clients if you and I have a full-time job one of my first jobs back in the I guess was the late 70s one of my first Jobs was a I collect dishes a busboy at a restaurant in Camarillo California and I would click the dishes and bring them back and then I upgraded I got a better job as a waiter I couldn't serve alcohol and the old but as I did get older I was a waiter and so if you and I went into a restaurant and someone comes to take our order they're providing us a service so in that context us or the client we as a client would be the customer and the server would be providing service now behind that waitstaff there's also people who are preparing the food and doing a whole bunch of other things to deliver that food to us so in a computer network anytime we think of the concept of a server it's some device that's providing a network function or service let's take a closer look at our diagram and make sure we're both clear on that idea so let's take this server right here so when we say a public-facing server it that implies that we have a server that is reachable by the public so in this case reachable by people on the internet so as far as what kind of service could a server provide let's let's talk about some common ones for example web services I mean just think about the last time you went to a website like well we mainly like Keith like two seconds ago when I got in the stream or watching this video yes that's a great example or we might have some type of file services that we're getting on online or we can have some kind of streaming service that we're getting or we could have some kind of a service so basically a server is providing some functionality some service that we're consuming and so file services and web services are great ways to think about that to kind of keep them straight like so any device on the network that's providing a service providing information providing a function is can be considered in that moment a server so if we have one of these devices and let's say it's a web server that in that moment is acting as a server so let's take a look next at clients so clients would be somebody who's requesting the services that's it so if we look at our topology again a client could be like this guy right here now in my it might come to I'm gonna let you in on a little secret and my when I discuss networks and talk about users I usually use one of two users I use Bob or Louis and I'm going to reveal why that is my father who is 90 years old his name is Bob and his last his Barker so that's kind of funny anyway it's not the same Bob Barker but and my mom's name is Lois and so that's why I use Bob and Lois as individuals as examples of users on the network so what it helps me to do is what I'm talking about or we're learning about concepts I like to involve and visualize or imagine the actual user who's using the network because that kind of gives a better or bigger picture of how its functioning so if we go back to our topology here we have Bob who's sitting at this computer and Bob opens up a browser so a browser there's lots of browsers out there web browsers things like chrome things like Internet Explorer and now edge and Firefox and Safari and other third-party browsers but those browsers are programs that are running on the computer that are acting as and can use the protocols or to use services from network devices so well that I was Bob as a client and his software running as a client to reach out and connect to a server and get those services so boom that's on our checklist what is a client or a server a server is providing some type of a network service and a client is consuming or asking or requesting for that service no I do have another question for you and and that's this and then you clear off my screen what if at one moment we have a device that's making a request it's going out to the internet asking for information and then a moment later it's actually providing a service to another client so maybe it's a device here let's go ahead and pick this device so this is a teeny little Raspberry Pi that has lots of capabilities but anyway let's imagine this is a device and at one moment it is providing a network service maybe somebody's connecting to it over the network and requesting web pages and the same time this is reaching out to another device and requesting time services to find out what the accurate time is well in that moment this device is acting both as a client and a server it's acting as a client asking for the time it's also asking about acting as a server when it's providing web services so when we talk about clients and servers it really depends on the exact you know the exact moment or what the function is at that moment and lots of devices in fact most devices on networks are acting as some type of a client for something and also as a server if it's like a web server or file server and so forth and that includes streaming so if you're a fortnight fan there are servers out there providing those services and your client your PCs are acting as clients requesting and consuming those services as you interact and crush the game alright I like for tonight I'm not good at for tonight but it's amazing and also check this out I have a have some family members who are really into gaming and whenever the network isn't working correctly or they feel like hey this isn't working right I'll tell you one of the major benefits of really understanding how the pieces all fit together and that is when something goes wrong you can check your piece of it you're part of it you say well there's the four steps I'm responsible for my computer as a client on this network let me check those four things out and verify there's not a problem locally and then if it's on the internet or at the remote servers there's not as much we can do but the cool thing is you can check locally once we understand the pieces that's the benefit of the second part here that I'd like to talk about and that is the the benefits of layers and let me go and bring the screen back up so layers are amazing and you might think well Keith what do you mean like layers like if it gets cold we should have layers so that we can you know keep warm or keep cool yeah there's layers in that sense as well but there's also the concept of individual components or pieces that can all work together that we don't have to understand all of it at once a great analogy is for like let's imagine only tape what is it Sunday um Thursday my wife and I flew up to San Francisco for a couple days to see some friends see a Cirque du Soleil show that was there Anna Luna it was really fun and we also got to go see a movie and this movie was actually a movie on the big screen at the Symphony Hall in San Francisco if you ever have a chance to do this it's so fun it was breathtaking I was just like I'd never experienced anything like that before so let's consider a theater whether it's the symphony hall or a movie theater you know there's a lot going on and to make that all happen oh there's concessions you know or there selling food or or snacks and things like that there's ticket sales they've gotta get the we dialed in they have to order that us get this because the agreement for that what else that they have to have assure they have to have people who help them to their seats they have to have fire prevention in the building and probably exit signs and there's just a ton of stuff that goes into a production like that so if it's a movie theater or it's a symphony there's just so much going on it wouldn't make sense for us to go in and say yeah we're gonna go ahead and define all this boom there it is everything every aspect of it it would make sense for us to take individual parts of that and break it out and then better understand those parts and how those parts all work together that my friend is the benefit of having layers inside our computer networks that way we can say oh this is a layer three deal function and then we can focus just on that so the objective here is to see the benefit of layers and the benefit of layers is that we take each individual component on its own and then focus on that part of the network functionality and how it works to really better understand it so that's that's objective number two understand the benefit of layers now now that I've said that let me show you some layers and a long long time ago in a galaxy far away I learned Novell and you're thinking what the what's Novell that's a good question if you're under 40 um Novell back in the I guess late seventies early eighties was the network operating system on the street and this is before computers had tcp/ip as a protocol that came native with them anyway so back in the early days I was taught in my early days of networking to learn what I referred to as the OSI reference model which is this bad boy right here we get out the appropriate tool there we bring this up so this OSI reference model it was it's a model it's not like nobody really uses it it's just an idea of chunking up or sectioning out functionality in the network but like that going to a movie theater and then breaking out okay here's a lot of concessions work or breaking out okay here's how to sails work or here's how the the the seating arrangement works and here's how the air conditioning works and so forth instead of treating it all like one giant lump we have layers of functionality and this OSI reference model had seven layers and if this is 20 years ago I've have you memorize those newsflash it's not 20 years ago but in the original OSI reference model which is still around as an idea or framework yeah there are seven layers and so in the old days we'd memorize those okay I'm gonna memorize all seven and we had mnemonics for memorizing those it was real party today we don't use the OSI reference model literally but we do use something else we use something called the tcp/ip Wow that's a mouthful of letters a tcp/ip protocol suite and let's take a look well let's talk about the word protocol first um my goal for us you and I is to see every component that we're every every aspect that matters for computer networking and make sure that you and I get it that we understand it there's not like I don't know that I want us to both I'm going to just gradually step by step I want us all to be very comfortable with the basics and then how networks work then we'll build on that as you and I enjoy this together and we continue so let's talk about when I was young I was born in 1964 it's a long time ago but when I was young I was in a anyway for whatever reason I learned Morse code Morse code and Morse code is a combination of dots and dashes so a dot would be represented by tapping like once and dash would be a longer period of time so I learned SOS dot dot dot dash dash dash dot dot dot it would sound something like this there we go SOS and that might come in really handy sometime if that's you know if we could communicate with that now SOS is only effective for me to do it or us to do it if we're sending a message and there's somebody else who hears that message and who what's the word I'm looking for understands it so if you and I are the only two people on the planet that understand SOS and the the set of rules regarding how it works it's not gonna be too effective unless you know they're talking to each other we can't talk to the outside world but fortunately there's a you know a lot of people at least in the past who learn in military who learned SOS or learn Morse code and so the benefit is we have a set of rules of how Morse code works like SOS so we're using the correct rules of saying SOS in Morse code and then something else who understands that same set of rules could interpret that saying oh that means SOS great so what does that got to do with networks SSO Morse code is an example of a protocol a protocol is a fancy word PR OT o co L it's a fancy word that means rules a set of rules or agreements so somebody somewhere developed Morse code they agreed to it as a protocol that they could use with other people who also understood that set of rules that protocol and then they can talk back and forth now here's the great thing with networks there are protocols which is a fancy way of saying a set of rules lots of sets of different rules that if they're followed by one device another device on the network can interpret what that means and that's how we can move data back and forth by following the same set of protocols so that's our another objective for today was to understand what exactly is a protocol and a protocol is a set of rules that two parties on the network agree with and the network can then allow those devices to communicate because it's just like Morse code they understand how the other is communicating because of the rules of protocols and then they can communicate with each other by following those same sets of rules so as I look at my notes here our objectives were to identify you know what exactly is that client or server a server is a device that's providing a network service like a web server we're going up to Google's web server or DNS server sales and we're getting responses back were acting as a client it's acting as a server and we're having network communication the reason that works is because we have protocols that our browser is using in the background so we open up our browser we go to WWE my favorite website comm we press enter and boom magic happens but you and I what we get to do is realize that it's not of course magic that's a set of lots of sets of rules or protocols behind the scenes that are agreed to and being used and that's why it's working and so as we progress through these CCNA Sundays together we're gonna take a look at the individual like we're going to specialize in individual areas of the network overall function on how it works and some of those areas are going to involve the layers and ectomy let me clean this up to an appropriate level so that it makes sense let me get out my one of my favorite tools and one of my favorite tools with annotation here is the eraser tool so you mean Keith we don't have to memorize the OSI reference model and I'm saying correct because that was a long time ago I'm gonna show you with you here in a moment something that is important to remember but it's not the OSI literally so we don't need to memorize the OSI reference model and so at the same time the OSI reference model was being you know touted as a framework or an idea of how to you know consider the individual compartments or components of a network functionality the tcp/ip protocol stack was being developed by the US government Department of Defense and it became the actual main thing that's being used so today we actually use this protocol stack and when we say a protocol stack let's break that down protocol is simply an agreement write a set of rules that we're agreeing to and a protocol us as a set of agreements that all kind of work together we could call that a stack of agreements that all work together or we could call it a protocol stack so when somebody says a protocol stack it's basically saying a set of different rules that are all designed to interoperate work with and cooperate with each other so we can demystify that and not have to worry about it any time we hear the word protocol or just in fact anywhere coding programming networking the word protocol simply means a predefined set of rules that hopefully at least two devices are more agreed to and then they can follow those rules those protocols for success so whether we're writing software applications or automating a network or changing the configuration of the Cisco router or switch we're simply configuring and working with the protocols to make them cooperate and work with each other all right back to the whiteboard here so we use the tcp/ip protocol stack however we we thought you know what it's kind of cool that the OSI reference model chopped up the individual functionality into layers so what they did was and I like it erases too because this one here is no longer I mean unless you're just let me ask you a trivia question which we're not about that here we are about how do networks work how do we get good at working with them and that value that we bring because we understand how the network works then eventually how to configure them and troubleshoot them yep that makes us more valuable it makes us more valuable to ourselves and our families and our employers and it makes work fun because there's a problem or something comes up to me oh yeah I I in fact when I use troubleshooting all the time with computer networks and that's because things don't always go right but when something does go wrong like there is a gamer in my in my within a hundred feet and that gamers like ah I just know that either that gamer lost something or there is a network issue and I can dive right in and say okay great let me check the Wi-Fi let me check the ethernet let me check the speeds here let me check this distances and I can identify if it's a local problem and it is not a local problem then it's outside our control sometimes but it's good it's good and also like like VR mm-hmm I enjoy virtual reality um it is so amazing so you put I have a quest headset it's the end of 2019 probably a year or two there would be something amazing even better anyway it's fantastic but if I if I analyze that network traffic and what's really happening is it still using this protocol stack and this set of rules the answer is yes yes it is so this information is gonna benefit you whether you're supporting a network in the corporate environment or at home or at a friend's house or or wherever it's really great to have an idea of how these layers all work together which we'll do in separate in subsequent videos so going back to our drawing here we have these one two three four these five categories of functionality and I'm not going to ask you to memorize these yet because what I would like to do is point out that in the world of networking we have these layers and let me actually change that color this would be great you bring this up and let me use the there we go I'm not color code them so it's very easy to see so we have like at the application layer there are sets of protocol or rules and programs and applications and services that can run to provide network services so let's imagine that we have a user like Bob and now that's and now that's our insight joke by the way so we've got it and then I my dad's amazing he's 90 he can do VR standing his balance is amazing and I also compete with him on for exercise like number of minutes standing and so forth he never loses he never never loses amazing okay so if Bob is sitting here at his computer and Bob opens up his favorite browser and this is just an example of how a protocol stack a set of protocols might interoperate work together and we're gonna cover individual detail on each these layers in subsequent live streams so Bob's it is browser you can imagine whatever you'd like that to be it might be Safari it might be Chrome might be edge might be Firefox whatever browser you know Bob chose to use now behind the scenes if Bob goes to www.vitac.com so he goes to the fav site comm and then behind the scenes that's going to be translated into a an IP address which we'll talk more about as well so behind the scenes humans like to use names like save site comm or twitch comm or YouTube calm but behind the scenes behind every single name there is an IP address IP is an acronym for Internet Protocol address sort like a street and house name are number like if you get mail at your house these the envelope is addressed to you at your house address on a common street that you have with your neighbors and so that's what IP addresses are about we'll take a closer look at that as well okay so behind-the-scenes though when Bob makes that request what his computer is actually doing is using an application layer service called web services and they have a fancy name for that and that name is HTTP hypertext Transfer Protocol or HTTP and these are just examples well we'll take separate looks at each of these layers and then with that application layer service from a service can be providing the web service if Bob is requesting before Bob spits that packet or that information out of the network so let's say Bob is connected to a switch a switch is a network device that can forward traffic in the right direction we might also have a router router is also another network device that can forward traffic in the right direction so let's imagine Bob is up here and Bob wants to go to this server at fav site comm well behind the scenes before his computer starts spitting out that information into the network his computer is going to take that request at the application layer and it's going to do something called encapsulation being mean it's going to add it's going to add some information based on layer 4 and there's a couple of main protocols here at layer 4 and we'll have separate videos on all those one of those is TCP it stands for the transmission control protocol and if you and I were going to send a very important letter somebody and we wanted to make sure it got there we might ask for a receipt you know I guaranteed delivery with a receipt and that's what the transmission control protocol does at the transport layer here in this tcp/ip protocol stack it's reliable can it basically makes sure that it's okay to talk to that person on the other end the server it also gets little receipts occasionally to confirm Oh yep you got it great here's more and so forth so basically before Bob sends his data on the network not only is he requesting a web service but he's also gonna be using another protocol another set of rules that's going to verify that the the information got there and the response came back and everything else behind the scenes so Bob is just blissfully going but behind the scenes we're going to use other protocols at the various layers so as that traffic continues to work its way in the brain of Bob's computer and browser it's also going to include information about the addresses involved the IP addresses and so it's gonna add Bob source IP address so I'm extending a letter if we if if you and I were going to send letters back and forth to each other through the mail I would put on your IP address as the destination if you're sending it in message to me you'd be sitting it to my IP address for my house number and street name so basically IP addressing is a lot like street names and house numbers and it has to be added or included before Bob spits it out on the network because network devices need information to go ahead and forward it and then as Bob's computer continues to think about this requested it setting out it's also going to go ahead and include something called a layer 2 address or a MAC address and we're gonna save all those details for the very next string which is going to happen on look at my sunday xi 8 basic 8 I'm sorry I'll look at the date for next Sunday but it'll be at 11 a.m. next Sunday will be our next dream when will will start it at layer 2 so Bob includes all that information and then Bob spits that information onto the network and then the network devices forward it in the direction of the server who then opens it up sees the request and then responds back to Bob so the actual details about these protocols these rules that happen at each of these respective layers we're gonna save that for future discussions and then the cool part is this we don't have to master it all of us we can say ok great let's focus on like you know what happens at layer 2 why is it important what goes on there and we'll do this in our treatment for layer 3 what happens there and layer 4 and the application layer so there are three basic things that I wanted us to take away from this chat this discussion first was clients and servers a client is making some kind of a network request whether it's for a file server or a web server or a twitch server or some other stream or something else it's making the request and the server is providing the response based on the request from the client the second thing I would wanted to do is chat with you about the benefit of layers the benefit of layers is that we don't have to just understand everything all at once we can say you know what I understand there's some basic layers basic separate compartments are departments inside of network operations and now that I understand that the protocols are simply rules that all kind of work together in our next and subsequent stream we can focus on how each of those protocols and what those protocols are protocols like HTTP and protocols like TCP and IP and so forth because those are all protocols sets of rules that we're using to communicate over a network and the third thing I want to do is I want to do the benefits of layers and then also demystify protocol stack so a protocol stack is a grouping of rules or protocols that can work together and interoperate together and as we continue these CCNA Sundays we're gonna next tackle layer two and take a look at what happens there with examples also you know what we can also use protocol analyzers too it's one thing to understand the concept of okay there's layers and here's what happens at that layer but it's another thing to actually see it and you might say well Keith how do we we see you know the the computer is doing all this work and all this all these protocol stack elements working together it spits out the network information on the network how do we see it and the answer is we scoop up that information off the network and then we have a program called a protocol analyzer or a packet capture software that can show us the details so that way it becomes more than just theory we can actually see oh here's the this layer stuff and here's this layer stuff like the application layer and transport layer and IP layer Network layer and we can actually see it to reinforce the concepts so we'll take those step by step as they come and those were our three objectives that I wanted to address and cover in this live stream as a warm-up to ccmn and these concepts by the way they apply to everything IP so whether you're pursuing CCNA or network plus or just want to know more about how the network works as we dive in we'll be taking a look at each of the layers also what you and I can do to troubleshoot and verify that those layers are working correctly if something goes bump because that wasn't above bump in the night and is working so let me go ahead and bring up our objectives one more time just to confirm and here they are yeah they're there yeah let me get rid of that one later right there okay so what are the roles of clients and servers or the benefits of layers and what is a protocol stack so I guess as a test of how did we do collectively one of the things I would do is maybe contact a friend a loved one a spouse partner anyone that'll chat with you for a moment and I encourage you to take the challenge of explaining these things to a person who is a non IT person what are the roles or the you know of a client or server what makes a device the client or what makes a device deserver what's the benefit of layers and what is a protocol stack I put it in quotes because really a protocol is something simply a set of rules and a stack of rules is simply a bunch of rules that cooperate and interact with each other so the benefit of chatting with somebody else and walking them through this is that it can help identify areas that like oh how does that work again or you know I don't really understand that as well as I need to at this high level let me go ahead and watch this video get on this live stream also what I'd be happy to have you do and what I'd love you to do is in the comments section know for this presentation because I'm talking with you like 100 percent I haven't had a chance to look at the comments yet so I'll get to those in just a moment but if you see a comment whether it's this live stream happening live or it's posted and something has a comment and you know the answer to it it's me as a question my encouragement is to jump in and answer it help them help your neighbor your brother your sister or your fellow human as they start to internalize this and better understand it this is it's a fantastic journey in the world of networking I love it I absolutely love it so what do that do is this I'm gonna put some music on for a few moments and I'm gonna take a look at the cube real quick see if there's any questions that are burning that I need to answer immediately for us here in the livestream and then I'll come back with one follow-up insight as to a couple things that I'm creating that I think you'll love as well so give me just a moment I'll put some music on and I'll be right back [Music] [Music] all right and I wanna I want to think wow there's several people who've responded oh nothing Mike way to go ha ha ha Mike in there yeah answered questions and I appreciate that that is fantastic and I looking at the responses Mike you're spot-on for anybody's pursuing ccnp and they're like part way through it before 2020 February 2020 there is a tool called a Cisco migration tool mmm is it called Cisco migration or Cisco certification tool let me look it up real quick and actually I'll add it to a comment in this once this gets posted as a recording I'll go ahead and add that URL so you can find it and it shows you exactly what weight you have taken so far based on checkboxes and then what you'll get after February 24 2020 as a result all right so my thank you very much I appreciate you jumping in supporting our you know other people who are studying and learning fantastic ok so next week the 15th is what I'm seeing as the calendar item for that let me verify that yeah 15th is next Sunday so we're gonna do is we're gonna cover level to our layer - well do a quick overview of the protocol stack and how the pieces can work together and we're gonna focus on layer 2 you know I say we'll keep whatsit layer 2 well it's not in on the serious note layer 2 is freaking amazing layer 2 deals with switches layer 2 switches that forward frames based on the destination layer 2 addresses and it also deals with things like VLANs virtual local area network which I don't know why but the word VLANs is just amazing to me I like it's like villians it's pretty cool - also the concept of trunking is in there so I may break those out into separate sections but I want to do a really good discussion about layer 2 so that you understand completely that when Bob sends a frame into the switch that those bits how the frames make forwarding decisions here's a little spoiler alert they use the layer a layer 2 switch uses the layer 2 address for forwarding and then we'll follow that up in a subsequent live stream about layer 3 routing and IP addressing and the transport layer and the application layer so by the time we're done if you hang out with me every week for a few minutes you'll be very comfortable with how the protocol stack works how the pieces of parts fit together and and well then take that and we'll start applying it into a Cisco centric network interface our architecture which also would apply to juniper and HP and Palo Alto and Citrix and other vendors as well so the concepts we're going to learn about IP networking they apply also we'll take a look at ipv6 also as we take a look at layer 3 all right so I'll see you Ray next Sunday same bat-time same bat-channel also if you're interested I'm also doing on Wednesdays at 4 p.m. and I'll put out an announcement as well I'm doing this behind this thing behind the scenes sneak peek at some of the content that I'm creating at CBT Nuggets regarding the CCA and the dev net programs stuff I like to share when I can stuff that hasn't been released yet so that you get it like an inside view behind the scenes look at what that is and what's going on so I wanted to keep this close to 30 minutes I think we're I did pretty good again thanks for the support on the backend by having as a community helping each other with the questions and confirming I love it so have a great great rest of your day thanks for joining me for this live stream on CCA and then the link is gonna be oh gee I teach online slash CCNA zero one any guesses on what the next one any guesses on what the next one's gonna be yeah zero two that way I'll be very easy to find as well and that way when they're all done you can have a whole stream or a whole you know series in order of content regarding cisco certified network associate and more importantly the technology and the skills to be able to understand it configure it and hopefully with enough knowledge and practice troubleshoot it as well alright thanks everybody I'll see you in the next live stream [Music] [Applause] [Music] [Music]

Channel: Keith Barker

Views: 77,932

Rating: 4.9552135 out of 5

Keywords: ccna certification, ccna training, ccna 200-301, CCNA, new ccna, cisco ccna, cisco certified network associate, new ccna certification 2020, new ccna exam 2020, cisco certifications, 200-301 ccna, ogit, keith barker, networkchuck, networkchuck ccna

Id: sREx122-LUg

Length: 37min 55sec (2275 seconds)

Published: Sun Dec 08 2019