1 00:00:00,000 --> 00:00:00,930 In this lesson, 2 00:00:00,930 --> 00:00:03,270 we're going to discuss network components. 3 00:00:03,270 --> 00:00:05,250 Now, when it comes to networks, the whole purpose 4 00:00:05,250 --> 00:00:07,350 is to get data from one place to another 5 00:00:07,350 --> 00:00:09,240 and from one machine to another. 6 00:00:09,240 --> 00:00:11,790 Whether that's carrying voice, video, or data, 7 00:00:11,790 --> 00:00:14,520 it's going to have to get across the network somehow. 8 00:00:14,520 --> 00:00:17,550 So what does our networks actually consist of? 9 00:00:17,550 --> 00:00:20,040 Well, that's what we're going to answer in this lesson 10 00:00:20,040 --> 00:00:21,540 as we begin to explore the different types 11 00:00:21,540 --> 00:00:23,250 of network components that we utilize. 12 00:00:23,250 --> 00:00:26,940 Things like clients, servers, hubs, switches, 13 00:00:26,940 --> 00:00:29,250 wireless access points, routers, 14 00:00:29,250 --> 00:00:32,220 firewalls, load balancers, proxies, 15 00:00:32,220 --> 00:00:34,980 intrusion detection and intrusion prevention systems, 16 00:00:34,980 --> 00:00:37,650 controllers, network-attached storage devices, 17 00:00:37,650 --> 00:00:41,190 storage area networks, media, and WAN links. 18 00:00:41,190 --> 00:00:43,350 Now, some of those terms probably look familiar 19 00:00:43,350 --> 00:00:44,670 and others may not. 20 00:00:44,670 --> 00:00:45,810 So we're going to go through each of those 21 00:00:45,810 --> 00:00:47,910 very briefly in this lesson. 22 00:00:47,910 --> 00:00:49,890 Now, first we have clients. 23 00:00:49,890 --> 00:00:50,790 Clients are devices 24 00:00:50,790 --> 00:00:53,010 that users are going to access the network with. 25 00:00:53,010 --> 00:00:55,950 These are things like workstations, laptops, tablets, 26 00:00:55,950 --> 00:01:00,030 smartphones, smart TVs, and even Wi-Fi enabled thermostats. 27 00:01:00,030 --> 00:01:01,260 These can be any device 28 00:01:01,260 --> 00:01:03,030 that is simply going to connect to the network, 29 00:01:03,030 --> 00:01:06,210 and we refer to all of them collectively as our clients. 30 00:01:06,210 --> 00:01:08,130 Second, we have servers. 31 00:01:08,130 --> 00:01:10,890 Now, servers provide resources to the rest of your network, 32 00:01:10,890 --> 00:01:13,890 and some common examples include things like email servers, 33 00:01:13,890 --> 00:01:17,040 file servers, web servers, and many others. 34 00:01:17,040 --> 00:01:19,740 These servers can exist on dedicated hardware devices, 35 00:01:19,740 --> 00:01:22,230 or they can rely on some specialized software 36 00:01:22,230 --> 00:01:23,880 that allows a device to act as a server 37 00:01:23,880 --> 00:01:25,830 for other clients on the network. 38 00:01:25,830 --> 00:01:27,600 Third, we have hubs. 39 00:01:27,600 --> 00:01:29,430 Now, hubs are older technologies. 40 00:01:29,430 --> 00:01:31,830 They're not commonly going to be used in our modern networks, 41 00:01:31,830 --> 00:01:33,870 but they're still relevant for the exam 42 00:01:33,870 --> 00:01:35,160 because they often are going to be used 43 00:01:35,160 --> 00:01:37,080 as one of your answer choices. 44 00:01:37,080 --> 00:01:39,780 Now, hubs are devices that connect other network devices 45 00:01:39,780 --> 00:01:43,080 like clients and servers together over a local area network. 46 00:01:43,080 --> 00:01:45,270 However, they do have some limitations, 47 00:01:45,270 --> 00:01:46,770 such as increased network errors 48 00:01:46,770 --> 00:01:49,680 due to their broadcasting nature of these devices. 49 00:01:49,680 --> 00:01:52,170 Now, hubs were first developed a long time ago, 50 00:01:52,170 --> 00:01:54,300 but over time they evolved into bridges 51 00:01:54,300 --> 00:01:56,100 and then eventually into what we use today, 52 00:01:56,100 --> 00:01:57,600 which are known as switches. 53 00:01:57,600 --> 00:01:59,190 Now, switches are just, effectively, 54 00:01:59,190 --> 00:02:00,930 a much smarter version of a hub 55 00:02:00,930 --> 00:02:02,130 because our switches can learn 56 00:02:02,130 --> 00:02:03,810 which devices are on which ports 57 00:02:03,810 --> 00:02:07,020 and only forward traffic to those intended recipients. 58 00:02:07,020 --> 00:02:08,880 Fourth, we have switches. 59 00:02:08,880 --> 00:02:10,710 Now switches are really just smarter hubs 60 00:02:10,710 --> 00:02:12,210 that provide us with more security 61 00:02:12,210 --> 00:02:14,640 and more efficient bandwidth utilization. 62 00:02:14,640 --> 00:02:16,470 Switches are used to connect network devices 63 00:02:16,470 --> 00:02:18,255 and only forward traffic from one port 64 00:02:18,255 --> 00:02:20,340 to the intended destination port, 65 00:02:20,340 --> 00:02:22,560 and this helps to avoid unnecessary broadcasting 66 00:02:22,560 --> 00:02:24,480 of your data over the network. 67 00:02:24,480 --> 00:02:27,030 Fifth, we have wireless access points. 68 00:02:27,030 --> 00:02:30,210 Now, wireless access points, also known as access points, 69 00:02:30,210 --> 00:02:31,470 will allow wireless devices 70 00:02:31,470 --> 00:02:33,300 to connect to your wired network. 71 00:02:33,300 --> 00:02:36,360 These wireless access points, also known as WAPs, 72 00:02:36,360 --> 00:02:39,810 or simply as APs, are very prevalent in our homes, 73 00:02:39,810 --> 00:02:41,910 businesses, and large networks. 74 00:02:41,910 --> 00:02:45,060 Just like hubs, access points are used to broadcast data, 75 00:02:45,060 --> 00:02:47,400 but they do this over a radio frequency wave 76 00:02:47,400 --> 00:02:50,430 instead of going over a copper or fiber cable. 77 00:02:50,430 --> 00:02:52,140 Sixth, we have routers. 78 00:02:52,140 --> 00:02:54,630 Now, routers are a crucial component in our modern networks 79 00:02:54,630 --> 00:02:57,420 because they're used to connect different networks together. 80 00:02:57,420 --> 00:03:00,120 These routers can make intelligent forwarding decisions 81 00:03:00,120 --> 00:03:03,120 based on the IP addresses of the different clients, servers, 82 00:03:03,120 --> 00:03:05,880 or other devices that are communicating over the network. 83 00:03:05,880 --> 00:03:07,950 Modern routers are predominantly going to rely 84 00:03:07,950 --> 00:03:09,240 on the internet protocol 85 00:03:09,240 --> 00:03:11,130 to route the traffic across the network 86 00:03:11,130 --> 00:03:13,860 using many different types of routing protocols. 87 00:03:13,860 --> 00:03:15,840 Seventh, we have firewalls. 88 00:03:15,840 --> 00:03:17,790 Now, firewalls serve as a security barrier 89 00:03:17,790 --> 00:03:20,340 between your internal network and the external world, 90 00:03:20,340 --> 00:03:22,530 which is typically going to be the internet. 91 00:03:22,530 --> 00:03:24,420 These firewalls can monitor and control 92 00:03:24,420 --> 00:03:26,370 incoming and outgoing network traffic 93 00:03:26,370 --> 00:03:28,620 based upon predetermined security rules 94 00:03:28,620 --> 00:03:30,810 by using access control lists. 95 00:03:30,810 --> 00:03:32,370 Now, this is going to help protect your network 96 00:03:32,370 --> 00:03:34,500 from unauthorized access, cyber attacks, 97 00:03:34,500 --> 00:03:36,180 and other online threats. 98 00:03:36,180 --> 00:03:38,460 These firewalls can be either hardware based, 99 00:03:38,460 --> 00:03:42,030 software based, or a combination of both of these. 100 00:03:42,030 --> 00:03:44,100 Eighth, we have load balancers. 101 00:03:44,100 --> 00:03:46,470 Now, load balancers are devices or software 102 00:03:46,470 --> 00:03:47,670 that are going to distribute network 103 00:03:47,670 --> 00:03:50,490 or application traffic across multiple servers. 104 00:03:50,490 --> 00:03:52,770 This increases the efficiency, capacity, 105 00:03:52,770 --> 00:03:54,690 and reliability of the services 106 00:03:54,690 --> 00:03:56,250 by ensuring that no single server 107 00:03:56,250 --> 00:03:58,410 is going to bear too much of that demand. 108 00:03:58,410 --> 00:04:00,330 By balancing our requested loads, 109 00:04:00,330 --> 00:04:01,830 this is going to prevent any one server 110 00:04:01,830 --> 00:04:03,180 from becoming a bottleneck, 111 00:04:03,180 --> 00:04:06,090 and this will improve our overall network performance. 112 00:04:06,090 --> 00:04:07,740 Ninth, we have a proxy. 113 00:04:07,740 --> 00:04:10,080 Now, a proxy server's going to act as an intermediary 114 00:04:10,080 --> 00:04:12,510 between a user's device and the internet. 115 00:04:12,510 --> 00:04:15,240 This device called a proxy can provide functionalities like 116 00:04:15,240 --> 00:04:17,399 web filtering, shared network connections, 117 00:04:17,399 --> 00:04:20,399 and data caching to improve your overall performance. 118 00:04:20,399 --> 00:04:23,580 Proxies can also be used to enhance security and privacy 119 00:04:23,580 --> 00:04:25,350 by hiding the user's real IP address 120 00:04:25,350 --> 00:04:27,780 and limiting their exposure to the internet. 121 00:04:27,780 --> 00:04:31,380 Tenth, we have intrusion detection systems known as IDSs 122 00:04:31,380 --> 00:04:34,350 and intrusion prevention systems known as IPSs. 123 00:04:34,350 --> 00:04:36,900 Now, IDSs or intrusion detection systems 124 00:04:36,900 --> 00:04:39,570 are designed to detect unauthorized access or anomalies 125 00:04:39,570 --> 00:04:41,970 on your network and then alert the system administrator 126 00:04:41,970 --> 00:04:43,410 of those anomalies. 127 00:04:43,410 --> 00:04:45,270 Now, on the other hand, an IPS 128 00:04:45,270 --> 00:04:46,830 or intrusion prevention system 129 00:04:46,830 --> 00:04:49,860 will not only detect those threats like an IDS would, 130 00:04:49,860 --> 00:04:52,260 but it can also take actions to prevent the intrusion, 131 00:04:52,260 --> 00:04:54,480 like blocking that traffic from entering your network 132 00:04:54,480 --> 00:04:56,280 or dropping any kind of harmful packets 133 00:04:56,280 --> 00:04:58,860 that may be attempting to get into your network. 134 00:04:58,860 --> 00:05:00,900 Eleventh, we have controllers. 135 00:05:00,900 --> 00:05:02,880 Now controllers are particularly going to be used 136 00:05:02,880 --> 00:05:06,570 in the context of software-defined networking or SDN. 137 00:05:06,570 --> 00:05:08,700 These controllers are really central units 138 00:05:08,700 --> 00:05:10,770 that are going to be used to manage the flow control 139 00:05:10,770 --> 00:05:12,660 to those networking devices. 140 00:05:12,660 --> 00:05:15,390 This enables network administrators to dictate the behavior 141 00:05:15,390 --> 00:05:17,880 of the network switches and routers through software, 142 00:05:17,880 --> 00:05:20,850 and this gives us more flexibility and efficiency. 143 00:05:20,850 --> 00:05:24,720 Twelfth, we have network-attached storage or NAS devices. 144 00:05:24,720 --> 00:05:26,730 Now, an N-A-S or NAS device 145 00:05:26,730 --> 00:05:28,770 is a dedicated file storage system 146 00:05:28,770 --> 00:05:29,940 that provides data access 147 00:05:29,940 --> 00:05:32,160 to a heterogeneous group of clients. 148 00:05:32,160 --> 00:05:34,080 Now, these things are going to be connected to a network 149 00:05:34,080 --> 00:05:35,970 and they allow for the data storage and retrieval 150 00:05:35,970 --> 00:05:37,440 from a centralized location 151 00:05:37,440 --> 00:05:41,070 for authorized network users and all of those clients. 152 00:05:41,070 --> 00:05:43,380 Thirteenth, we have storage area networks, 153 00:05:43,380 --> 00:05:45,210 also known as a SAN. 154 00:05:45,210 --> 00:05:47,040 Now, a SAN or S-A-N 155 00:05:47,040 --> 00:05:49,110 is a high speed network that provides access 156 00:05:49,110 --> 00:05:51,780 to consolidated block-level data storage. 157 00:05:51,780 --> 00:05:54,150 SANs are designed to handle large volumes of data, 158 00:05:54,150 --> 00:05:56,430 and they're typically used to enhance storage devices 159 00:05:56,430 --> 00:05:58,560 such as disc arrays and tape libraries 160 00:05:58,560 --> 00:06:01,020 and make them accessible to your servers. 161 00:06:01,020 --> 00:06:03,150 Fourteenth, we have media. 162 00:06:03,150 --> 00:06:04,470 Now in the world of networking, 163 00:06:04,470 --> 00:06:06,570 media refers to the physical materials 164 00:06:06,570 --> 00:06:08,550 that are used to transmit the data. 165 00:06:08,550 --> 00:06:10,290 This can be something like a copper cable, 166 00:06:10,290 --> 00:06:13,530 a fiber optic cable, or even wireless signals. 167 00:06:13,530 --> 00:06:14,850 Each of these different media types 168 00:06:14,850 --> 00:06:16,470 does have its own unique properties, 169 00:06:16,470 --> 00:06:18,450 including its own strengths and limitations, 170 00:06:18,450 --> 00:06:19,830 and this will influence its use 171 00:06:19,830 --> 00:06:22,544 in different network scenarios that you may be designing. 172 00:06:22,544 --> 00:06:25,200 Fifteenth and finally, we have WAN links. 173 00:06:25,200 --> 00:06:27,780 Now, a WAN link or a wide area network link 174 00:06:27,780 --> 00:06:29,070 is going to be used to connect networks 175 00:06:29,070 --> 00:06:31,020 over large geographical areas, 176 00:06:31,020 --> 00:06:33,270 such as between cities or countries. 177 00:06:33,270 --> 00:06:35,760 WAN links are essential for global connectivity 178 00:06:35,760 --> 00:06:38,040 and they enable data exchange over long distances 179 00:06:38,040 --> 00:06:39,960 using technologies like lease lines, 180 00:06:39,960 --> 00:06:42,810 satellite communications, or cellular networks. 181 00:06:42,810 --> 00:06:45,090 So remember, understanding network components 182 00:06:45,090 --> 00:06:48,090 is going to be crucial in the field of information technology. 183 00:06:48,090 --> 00:06:50,520 From clients and servers to more complex elements 184 00:06:50,520 --> 00:06:53,160 like firewalls, load balancers, and WAN links 185 00:06:53,160 --> 00:06:55,020 each component does play a vital role 186 00:06:55,020 --> 00:06:57,480 in ensuring the efficient and secure data transmission 187 00:06:57,480 --> 00:06:58,980 of our information. 188 00:06:58,980 --> 00:07:01,260 Knowledge of these components is not only going to aid you 189 00:07:01,260 --> 00:07:03,480 in the design of your networks and its management, 190 00:07:03,480 --> 00:07:06,270 but it also enhances your ability to conduct problem solving 191 00:07:06,270 --> 00:07:07,500 and to implement security measures 192 00:07:07,500 --> 00:07:09,720 in an increasingly interconnected world. 193 00:07:09,720 --> 00:07:11,280 Later on as we go through this course, 194 00:07:11,280 --> 00:07:12,480 we're going to talk more about each 195 00:07:12,480 --> 00:07:15,180 and every one of these different devices, how they operate, 196 00:07:15,180 --> 00:07:18,053 and what they're going to be used for in your network designs.