Introduction to Networks

Khawar Butt
A free video tutorial from Khawar Butt
Hexa CCIE #12353 ,CCDE #20110020
4.6 instructor rating • 5 courses • 6,896 students

Learn more from the full course

Mastering IPv4 & IPv6 Addressing and Subnetting

Introduction to Networking with IPv4 and IPv6 addresses

14:13:01 of on-demand video • Updated February 2019

  • Introduction to Networking
  • IPv4 Address Classes
  • IPv4 Private Addresses.
  • IPv4 Fixed Length Subnet Masking
  • IPv4 Variable Length Subnet Masking
  • IPv4 Supernetting
  • IPv6 Address Types
  • IPv6 Subnetting
  • IPv6 Address Assignments using SLAAC & Manual Mechanism
English [Auto] Hey everybody. This is QR. I'm gonna be your instructor for this video on networks. This is the first video in this series that takes a look at the introduction to what a network is. It's basically a video that you start your journey into the networking field and I am excited to bring this video to you guys and in this video we'll get started and I'll take you I transport you back to an era that what we see today in networks did not exist. And then slowly build up the definition that what not a network is one of the uses of networks. We'll take a look at the different ways of connecting the network to each other. So let's begin. The first thing I want to talk about is what happened prior to the networks being there. Well how do we do computing by the networks being there. When I started in the industry in the early 90s networks did not exist. It was basically standalone devices that would have limited resources maybe a printer small amount of memory memory that you would scoff at when you talk or talk about it. If you hear about it like in my first personal computer that I had the first B.S. that I had I had four megs of memory not gigs four megs of memory and I was as ecstatic about it because it was a lot of memory on those days. I had a 40 meg harddrive meg hard drive not a gig hard drive. And it was more than enough to hold the data that I had at that time. So when I went to work in terms of a work environment you would have these standalone devices that would be connected. That would basically do computing for the office work like create a letter the word processing on it maybe create a spreadsheet. In terms of the accounts the application that existed where WordPerfect was a word processor of the time Lotus One Two Three was the spreadsheet application of the time. Those are basically the applications that you had. But as computing came into our lives especially at the workplace more and more applications came about. And that's where the need for networking came about. So in this particular video what we'll do is we'll take a look at how the initial networks are formed. We'll take a look at the definition of what network is the different ways of connecting the networks network types basically connecting using cables wireless a hybrid a combination of the two. And at the end we'll take a look at a review of what we have covered in this particular video. One of the things that I want you guys to be aware of. Keep your mindset along that lines is that when you're taking a look at the video rather than looking the amount of information that you need to study when you're looking at a particular video just focus on the topics of that video. My problem is you if you take a look at these. Take a look at the video itself. Approach it at one video at a time by the debt by the time all the videos are done. You would have complete knowledge of all the different aspects of networking but it cannot be done overnight. It will be done one step at a time. And this is your first step. All right. So coming back to what I was talking about in terms of the initial networks let's go ahead and take a look at what used to exist in that area and then I'll show you the slide show as well in terms of making you understand the the definition that I will go to over here. So as I said when you went into an office in those days you would have a B.S. maybe multiple personal computers and one of those computers would have an attached printer to it you would have a local hard drive and storage space was very expensive. Those days I remember getting my second hard drive was what. Eighty five meg hard drive for about two hundred dollars at that time. This is back in the early 90s. So if I had a 40 meg hard drive over here I could only store so much of data and if that same data needed to exist on multiple devices I would need to use a removable media like a floppy disk which would basically hold up to one point four to be exact one point forty four megabytes of data and I would copy my files onto it and give it to my friend who would access the same files on the same file existed in both locations and the printers. If I wanted to print something I would copy the file onto a floppy moved to the computer that had the printer connected to it open the file up and then print the document over here. So a very manual approach of sharing information or data with each other and that's where the need for networking arose to connect these different networks or these different devices to each other in a way that sharing would become a lot simpler and more efficient to do. So initially when the networks came about what they did was they used a special type of cable to connect these devices to each other. This type of cable was known as an argy 58 you cable which was which was a coaxial cable to all cable TV cable types. And the way it would connect up you would have to buy a new adapter for your P.C. called the Nick the network interface card. And each new each device would have to have this new adapter in it and this adapter would have a special connector that would connected into the Quick's cable the correct cable that you would connect it would connect into what was known as the T connector the connector had two ends to it to open it three ends actually one and would go into the adapter the mic and the other end would go into the running cable so I would run a cable over here between this connector to the other P.C. on the other P.C. again I would have a T connector which would have one end of the cable over here and the other end would keep on going to the other Nick at the end to indicate the end of the cable I would have what would know what was known in those days as the Terminator of the cable. So on this disconnect I would have two cables connected on the two edges I would have a terminated indicating the end of the cable. The problem with this type of setup was if if I could not when I did a communication or a transmission if I could not see the terminator the whole network would come down. So just in case there was a break over here the entire network would go down because when I was transmitting I could not see the end of the net cable. So even the two devices over here let's say P.S. One NBC two even these two pieces could not communicate to each other although the cable break was between two NPC three so slowly this type of cabling model went away all right. This gave way to a better way of doing networking which was using a device in the middle called the home so rather than having this bus stop architecture we went to more of a star type architecture in which each device would connect up into a central device known as a hub or also sometimes referred to as a multi repeater repeater basically was a device that would make a transmission and repeat repeated or send it to the other devices. Basically it was just an intelligent device that would take a signal and send it to all the other devices connected to the hub the cabling changed it changed from the RG 58 you cable to the RG forty five cable which was the unsealed shielded twisted pair cable the UDP cable that connected your P.C. you see one easy to NBC three all the three devices would connect to the central device called the Hub and because they were connected to the hub they would connect each other now in this type of setup. The good part about it was just in case one device went down it did not break the entire network down because BCE too could still communicate to be see. So it was a better way of doing things easier to troubleshoot fault isolation was there but the problem with the hub was that when this device sent a transmission because it was an unintelligent device the transmission would go into the hub. How would send the traffic even if it was just meant for P.C. to. It would be sent to all the other devices so unnecessarily. B c 3 would you have to listen to transmissions that were really meant for B.C. to so quickly they changed this media. They optimized this media or this device from a hub even more intelligent device called a switch the function. Functional difference between the two devices was the intelligence that was built into the switch in the sense that when you see one send the traffic which was destined for B.C. to the switch would look at the destination and over the packet only to switch only to B.C. to B.C. one wanted to communicate to B.C. two it would not send the traffic to the other pieces as well so it would allow multiple devices to communicate at the same time. So this was the central device and even today most of the wired networks that you guys have are using some form of a switch to connect these devices to each other. All right. So this is our networking started. Now Wow. Why did I do networking again in the first place. Because if I did not have networking the resources that I had were isolated to the standalone device that I had my disconnected B.S. The personal computer. So if I had a printer connected over here if I did not have a network I would need to do that copying of the file onto the floppy moving the floppy manually to the P.C. to print it out. So by doing this now I had the ability to take a print job open the file up on my P.C. and send that file to the network to see three to print it out so this allowed us the ability to share our hardware resources like a printer across the network. The other thing that it also did now rather than saving the files on local hard drives I could get a more sophisticated device known as a server and put a bigger storage device or put a bigger harddrive over here and allow all the different devices just for their files on this centralized harddrive so if you see one had a file that it needed the other guys to view or look at or share he would share or he would store the file on the harddrive which was easily accessible by anyone on the network. This type of service was known as a file service and the server was called the files. So the initial networks that you guys had were based on this file serving capability and the print serving capability so these were your initial networks. This was the initial need for networking. This was how the networks evolved in the early ages. Now it has gone to a different level once these networks came about. They connected it up to each other which is what we know as the Internet. It's not just now used for sharing files or sharing storage space. It is used for other things as well. Communicating to each other by sending emails to each other communicating to each other by virtual of chats on WhatsApp or Snapchat application that connect different networks to each other which is the Internet to share resources with each other not only that information. If I want to go to a place let's say I want to visit a place before I even go there I want to find out what the weather is in that place. What are the different places that I want to go and visit or view in that location. I can find that information on the network so information sharing became essential by connecting these devices to each other. Now I could put up information that could be used by other users of the network. All right so this is what networking did for us. Now let's go back and take a look at the the definitions of these networks real quick. Now that you understand a little bit about how the networks came about so I'll start for the initial networks as I said the initial networks were what standalone devices every device had its own resources whether it was the harddrive whether it's whether it was a printer it was all directly connected to that device and we will need device that could use it was a device that was connected to so the resource was directly connected to the device that included the printer and storage devices scanners which was a device that was used a lot in those days. What happened with this was the loss of productivity. What do I mean by that. Again as I said as I explained to you if I wanted to print a file and I did not have the printer directly connected to me I would have to copy the file onto the floppy disk the floppy to the device that was connected to the the printer open the file up and print it. That's this option over here. This is what I'm talking about over here this again as I said was not efficient way of doing networking. This is where the networking now connect the devices to each other and that's what I explained to you guys in my initial set that we talked about. Now that's where the networks came about and that is what a network is over here. It's basically a number of computer systems devices like printers connected to each other. You can connect the devices using the physical cables like the switch that I talked about. And in a bit I'll also talk about the wireless connection how the wireless connections made it even easier for these devices to connect to each other. The main objective of that was to share hardware like printers or input devices like scanners your storage space which is your hard drive. You again talked about that already the file servers and then it evolved into a different level when the Internet where you connected all the different networks to each other allowed us the ability to write emails letters to each other instant messaging like WhatsApp Facebook Messenger or chatrooms where you could chat with your friends in a shared chatroom. Not only that nowadays you also have the ability to leverage the cloud services of companies where you don't need to install software packages on your devices you can actually use word processing or spreadsheet applications or your slide presentation slides on an app on the cloud where you don't need to actually install the word processor on your device you use a device that you use the software package that is actually installed on the cloud. Examples of these services are services like the G drive the Google applications the suite of applications that Google gives you or Microsoft also provides the same capability with their service for one gripe so you don't even need to install the application. Yes you need to pay for it but it's a subscription based model rather than just installing it and using your resources on your device. This is where this is what the networks are all about. Now the different ways of connecting the networks we talked about one of the ways to do it is the Wired where the cable is connecting in. Let's take a look at that first the wired network and then we'll take a look at the wireless as well. So what did the wired network in which basically the devices like computer your printer are all connected to each other using cables so they're connected into the network and at the center of this network is your switch. Although I also mentioned the hub. Nowadays you probably will not find out if you want to find a hub. You'll probably have to go to a computer museum to find a hub or a very old network. Nowadays most of the time the central device in your network is going to be a switch and I already explained the difference between a hub and a switch. Now what does it look like. Let me give you that as well. A hub. I'm not going to show but let's take an example of a switch over here. So I've shown you two images over here. This is what a normal switch would look like. This is the actual image of what a switch would look like. It would have different ports it would connect your he sees your laptop to your servers your printers to this central device known as a switch. And because they're all connected to each other you would allow the different devices to talk to each other. Now although this is the physical image of the switch in most of the network diagrams a stencil the image that they use representing the switch is not going to be this they're going to depict the switch using this image or this icon so get used to seeing it like that. So whenever you see an image like that you need to know this is a switch that is connecting all these different devices whether it's pieces or your servers or apprentice to each other. So you would take that RJ forty five cable or if you have the newer cables which are called the fiber optic cables the fiber cables which gives you higher speeds to connect the devices each other on a wired network. Now the problem with the wired network was that in order to set the wires up sometimes it becomes hard to do that because you need to run the cables running the cables if you keep them over the floor in trip somebody up looks very clunky. So one of the things that you would do is you would run them under the floor maybe in the ceilings to the walls so your network your building your office environment needed to be set up with these cables be installed. So to get around that they say why don't we use radio frequencies to send the signal send the data across rather than using these wires which caught on pretty quick. And nowadays most of the networks most of the new networks try to stay away from the the wiring especially towards the end users and instead use a wireless network to connect the devices to each other. What's the advantage of a wireless network basically using radio waves rather than wires to communicate between the notes so you don't need to have any clunky wires all over the place made it easier to deploy a new network. Bring up a new network quicker. So this is one of the common more popular ways of connecting that have different devices at this particular time although you do that for your end user just servers your bigger devices are still using the wires to connect up but you're eliminating a big portion of it in your home network. So this is the most common way of connecting the different devices to each other. So what is what is the device that connects them to each other. Do the devices talk directly to each other. Generally not what they do is just like you have a hub or a switch in a wired network in a wireless network. You have this device known as a wireless access point which is equivalent to your switch in your wired network. So you set it up in the middle you use wireless adapters the Nick that you get is not a wired make it to wireless Nic. It will allow you to transmit using this wireless capability allowing different devices that are using wireless to talk to each other. All right. Same concept same connectivity. The only difference is rather than using wired to connect up I'm using a wireless communication mechanism which is your radio frequencies to talk between the different devices. I've given you just it's a simple one example of what a wireless access point would look like. You have pieces using wireless communication to talk to each other because they're all connected to this same central access point. They will be able to use each other's resource and even the printers in today's day and age can be the wireless capability built in. So by doing this I'm getting way from the clunky nature of wires and allowing me to set up my network in a quick easy manner. All right. But the thing is that you still have a lot of old networks that would still have some aspect of the network which is wired. So that's where the hybrid network comes in. What is a hybrid network a hybrid network is where you have some element of the network which is wired and the other element is wireless. So the wireless access point would connect all the wireless devices to each other. But at the same time the wireless access point would have a cable connecting the wireless access point to the switch allowing the bridge between the wireless communication and the wired communication. An example of that again on a network topology now that you've seen what a switch looks like what an access point looks like would look something to this to the effect of this where you have wireless networks connecting all the wireless devices to your access point over here using wireless media once it's connected over there the wireless access point would have a wire going into the switch allowing the communication between the Wired devices to the wireless devices. This is a very typical type of environment in most of your offices. In today's day and age where you have an element of Wired devices as well as a wireless access point although in a home network you probably are not going to see a switch you're probably going to see a wireless access point connecting all the different devices to each other. This is a typical office environment that you'll be exposed to as we go to it so again to recap what we talked about in this particular video was an introduction to networks why do networks exist. What is the use of networks. What are the main resources that are used on a network. And then we took a look at the different ways of connecting the network to each other. Let's do a smaller review over here have some basic questions over you. What does the network. Basically connecting. Who are more devices that might be a computer or a laptop maybe a smartphone maybe a tablet each other to share information and resources with each other. What type of resources do I have that I can share. You can share storage spaces the hard drives you can share printers scanners with each other in terms of information information in the form of maybe emails accessing the internet and finding out information about different locations that you want to visit maybe. How do you do a certain task maybe make a dish for yourself. You have information on the Internet with recipes on doing cook cooking. You have information about maybe going in let's say I want to do a small task like make a door you have videos on that on the Internet. That's information sharing the job so emails chatting with your friends that's another aspect of information sharing chats you have instant messaging like what's up all the different type of things that you can do on the Internet or on a network. Now what type of device connects the devices on a wide network. We talked about that as well. That would be a switch and what type of device connects the devices on a wireless network. That would be an access point. So now that we know what a network brings to the table we'll in the next video we'll take a look at the different types of networks that we have and that in that particular video we'll take a look at the definition of what a personal area network is what a local area network is what is a metropolitan area network or a wide area network. So you'll take a look at the different classifications often network in the next video. Hope you enjoyed it. As I said at this point all I want you guys to understand is what I've talked about in this video as we go to the different videos you'll build your information to a level that you'll be an expert in this particular field. Hope you enjoyed it. See you in the next video.