title
TCP/IP and Subnet Masking

description
Level: Intermediate Date Created: November 19, 2010 Length of Class: 69 Minutes Tracks Networking Prerequisites Introduction to Networking Purpose of Class This class teaches students about the components and concepts in a TCP/IP network. Chapters TCP/IP Overview (2:32) How TCP/IP Works (16:53) TCP/IP Numbering (43:00) Subnet Masking (48:17) Final Thoughts (64:03) Class Notes 1. TCP/IP Is technically a Protcol Suite IP Routes Traffic Layer 3 OSI Model Network Routable Networks (sub networks) TCP controls transmission between connected systems Layer 4 OSI Model Transport Windowing is the process of sending data from one computer to another in TCP/IP version 4 2. How TCP/IP Works IP Addresses -- Every device on a TCP/IP network needs an individual IP Address DNS (Domain Name Service/Server) resolves Domain names into IP Addreses DHCP (Dynamic Host Control Protcol) Servers automatically assign IP information to clients for a specific time period (Lease). Clients try to renew leases at 50% expiration point. Default Gateway (Router) connects networks. If an IP Address cannot be found on the local network the computer tries to use the Default Gateway to find the target. Subnets and Subnet Masking -- Subnets are individual networks. Subnet Masks divide IP Addresses in Subnet Number and Host Number What the Number Mean IP Addresses and Subnet Masks are made of 4 Octets of Bits 128-64-32-16-8-4-2-1 Subnet Masking IP Addresses contain the Subnet Number and Host Number. The Subnet Mask tells you where the subnet number ends and the host number begins. Classful Networks A, B, C,D,E Gone now use CIDR The Highest Address in a Subnet Range is the Broadcast address To determine the number of subnets (n is the number of bits used)= 2n To determine number of Hosts = 2n -2

detail
{'title': 'TCP/IP and Subnet Masking', 'heatmap': [{'end': 1175.292, 'start': 1080.696, 'weight': 0.735}, {'end': 1548.318, 'start': 1498.894, 'weight': 0.763}, {'end': 2509.338, 'start': 2461.946, 'weight': 1}], 'summary': "Covers tcp/ip version 4's dominance in networking and potential replacement by version 6 by 2020 or 2030, tcp/ip protocol suite, windowing in tcp, network components, dhcp for ip address distribution, nat's significance, and subnet masking's importance in identifying network and device identifiers within an ip address, including the role of routers in connecting different subnets.", 'chapters': [{'end': 452.072, 'segs': [{'end': 56.353, 'src': 'embed', 'start': 28.027, 'weight': 0, 'content': [{'end': 33.43, 'text': 'Back when I started 10 or 11 years ago there were lots of protocols that people used.', 'start': 28.027, 'duration': 5.403}, {'end': 40.617, 'text': 'People used TCPIP, people used IPXSPX, they used NetBUI, they used numerous protocols.', 'start': 33.49, 'duration': 7.127}, {'end': 45.302, 'text': 'Now, just about everybody uses TCPIP.', 'start': 41.098, 'duration': 4.204}, {'end': 52.489, 'text': 'Now, the class today, we are going to be talking about something called TCPIP version 4.', 'start': 45.602, 'duration': 6.887}, {'end': 56.353, 'text': 'So there are multiple versions of the TCPIP protocol.', 'start': 52.489, 'duration': 3.864}], 'summary': 'Tcpip protocol has become dominant in the last decade, with tcp/ip version 4 being the focus today.', 'duration': 28.326, 'max_score': 28.027, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U28027.jpg'}, {'end': 136.731, 'src': 'embed', 'start': 112.896, 'weight': 1, 'content': [{'end': 120.441, 'text': 'way back then, in 1999, they were telling us how everybody was going to go to TCPIP version 6, like in the next couple of years.', 'start': 112.896, 'duration': 7.545}, {'end': 126.805, 'text': "And now it's 11 years later and everybody is still using TCP IP version 4.", 'start': 121.101, 'duration': 5.704}, {'end': 129.626, 'text': "So if you learn TCP IP version 4, you're good.", 'start': 126.805, 'duration': 2.821}, {'end': 131.768, 'text': "We're going to be using this for a long, long time.", 'start': 129.765, 'duration': 2.003}, {'end': 136.731, 'text': 'At some point, TCP IP version 6 will replace version 4.', 'start': 131.928, 'duration': 4.803}], 'summary': 'Despite predictions, tcp/ip version 4 remains dominant in 2020, with version 6 expected to replace it eventually.', 'duration': 23.835, 'max_score': 112.896, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U112896.jpg'}, {'end': 245.702, 'src': 'embed', 'start': 188.183, 'weight': 3, 'content': [{'end': 199.687, 'text': 'The TCPIP protocol is multiple protocols all tied together into one thing that is called tcp ip.', 'start': 188.183, 'duration': 11.504}, {'end': 210.092, 'text': 'the main protocols in here, though in tcp ip, are tcp, which is transmission control protocol, and ip, which is internet protocol.', 'start': 199.687, 'duration': 10.405}, {'end': 215.935, 'text': 'now these are the main protocols, and they do two very important functions.', 'start': 210.092, 'duration': 5.843}, {'end': 220.865, 'text': 'the first protocol that we should talk about is IP.', 'start': 215.935, 'duration': 4.93}, {'end': 231.212, 'text': 'So what IP is is IP is the protocol within TCP IP that controls routing of information to different computers,', 'start': 221.305, 'duration': 9.907}, {'end': 233.533, 'text': 'different devices and different servers on the network.', 'start': 231.212, 'duration': 2.321}, {'end': 236.735, 'text': 'So you will have heard of IP addresses.', 'start': 233.974, 'duration': 2.761}, {'end': 245.702, 'text': 'The IP protocol deals with these things called IP addresses, subnet masks, default gateway, DNS, et cetera.', 'start': 237.236, 'duration': 8.466}], 'summary': 'Tcp/ip consists of multiple protocols, including tcp and ip, where ip controls routing using ip addresses, subnet masks, default gateway, and dns.', 'duration': 57.519, 'max_score': 188.183, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U188183.jpg'}, {'end': 435.828, 'src': 'embed', 'start': 410.409, 'weight': 5, 'content': [{'end': 416.534, 'text': "so it's it's how computers discover each other, so so that they can can start communicating.", 'start': 410.409, 'duration': 6.125}, {'end': 420.797, 'text': 'well, once the computers have found each other, then they do need to start communicating,', 'start': 416.534, 'duration': 4.263}, {'end': 426.381, 'text': 'and that is where TCP comes in transmission control protocol.', 'start': 420.797, 'duration': 5.584}, {'end': 432.846, 'text': 'so this deals with once the computers have found each other, how are they going to talk.', 'start': 426.381, 'duration': 6.465}, {'end': 434.507, 'text': 'so so Hello.', 'start': 432.846, 'duration': 1.661}, {'end': 435.828, 'text': 'Hi Okay.', 'start': 434.847, 'duration': 0.981}], 'summary': 'Computers using tcp to communicate after discovery.', 'duration': 25.419, 'max_score': 410.409, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U410409.jpg'}], 'start': 5.236, 'title': 'Tcp ip and subnet masking', 'summary': 'Covers the importance of tcp ip version 4, its dominance in networking, and its potential replacement by version 6 possibly by 2020 or 2030. it also explains the tcp ip protocol as a suite consisting of tcp and ip protocols, with ip controlling routing of information and tcp regulating communication between devices, enabling the division of networks into smaller subnetworks and the use of routers.', 'chapters': [{'end': 163.947, 'start': 5.236, 'title': 'Tcp ip and subnet masking', 'summary': 'Covers the importance of tcp ip, the dominance of tcp ip version 4 in networking, and the reassurance that understanding tcp ip version 4 is sufficient for the foreseeable future, with potential replacement by version 6 possibly by 2020 or 2030.', 'duration': 158.711, 'highlights': ['TCP IP version 4 is the main protocol used for networking, with widespread adoption over other protocols like TCPIP, IPXSPX, and NetBUI. The dominance and widespread adoption of TCP IP version 4 over other protocols like TCPIP, IPXSPX, and NetBUI.', 'Understanding TCP IP version 4 is sufficient for the foreseeable future, with potential replacement by version 6 possibly by 2020 or 2030. Reassurance that understanding TCP IP version 4 is sufficient for the foreseeable future, with potential replacement by version 6 possibly by 2020 or 2030.', 'The chapter covers the importance of TCP IP and the reassurance that understanding TCP IP version 4 is sufficient for the foreseeable future, with potential replacement by version 6 possibly by 2020 or 2030. Covering the importance of TCP IP and the reassurance that understanding TCP IP version 4 is sufficient for the foreseeable future, with potential replacement by version 6 possibly by 2020 or 2030.']}, {'end': 452.072, 'start': 164.347, 'title': 'Understanding tcp ip protocol', 'summary': 'Explains the tcp ip protocol as a suite consisting of tcp and ip protocols, with ip controlling routing of information to different devices, and tcp regulating communication between devices, allowing for the division of networks into smaller subnetworks and the use of routers.', 'duration': 287.725, 'highlights': ['The TCP IP protocol is actually made up of something called TCP protocol and IP protocol, with the main protocols being TCP and IP. This highlights the composition of the TCP IP protocol, emphasizing the main protocols and the structure of the protocol suite.', 'IP is the protocol within TCP IP that controls routing of information to different computers, different devices and different servers on the network. This emphasizes the role of the IP protocol in controlling the routing of information within the TCP IP suite, specifying its function in directing data to various devices on the network.', 'TCP comes in to regulate the communication between devices, determining the language, speed, and other parameters for communication. This highlight focuses on the role of TCP in regulating the communication between devices, specifying its function in determining the parameters for effective communication.']}], 'duration': 446.836, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U5236.jpg', 'highlights': ['The dominance and widespread adoption of TCP IP version 4 over other protocols like TCPIP, IPXSPX, and NetBUI.', 'Reassurance that understanding TCP IP version 4 is sufficient for the foreseeable future, with potential replacement by version 6 possibly by 2020 or 2030.', 'Covering the importance of TCP IP and the reassurance that understanding TCP IP version 4 is sufficient for the foreseeable future, with potential replacement by version 6 possibly by 2020 or 2030.', 'The composition of the TCP IP protocol, emphasizing the main protocols and the structure of the protocol suite.', 'Emphasizes the role of the IP protocol in controlling the routing of information within the TCP IP suite, specifying its function in directing data to various devices on the network.', 'This highlight focuses on the role of TCP in regulating the communication between devices, specifying its function in determining the parameters for effective communication.']}, {'end': 861.329, 'segs': [{'end': 483.18, 'src': 'embed', 'start': 452.372, 'weight': 1, 'content': [{'end': 461.435, 'text': 'But what you should understand about TCP that becomes very, very important, especially as a network technician, is something called windowing.', 'start': 452.372, 'duration': 9.063}, {'end': 473.052, 'text': 'Windowing is the process by which the client computer sends information to the server computer.', 'start': 464.446, 'duration': 8.606}, {'end': 483.18, 'text': 'So when two computers are trying to talk, windowing is the process of how that data is sent from the one computer to the other computer.', 'start': 473.092, 'duration': 10.088}], 'summary': 'Tcp windowing is crucial for data transmission between client and server computers.', 'duration': 30.808, 'max_score': 452.372, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U452372.jpg'}, {'end': 528.582, 'src': 'embed', 'start': 507.512, 'weight': 0, 'content': [{'end': 516.538, 'text': 'so what happens if nuclear Armageddon has happened and you have diverse military installations trying to communicate with each other?', 'start': 507.512, 'duration': 9.026}, {'end': 520.08, 'text': "I mean that's a scenario that TCP IP was created under.", 'start': 516.538, 'duration': 3.542}, {'end': 528.582, 'text': 'so under that scenario, the government and the military realized that lines of communication might be very, very flaky.', 'start': 520.08, 'duration': 8.502}], 'summary': 'Tcp/ip was created for military communication during nuclear armageddon to address unreliable communication lines.', 'duration': 21.07, 'max_score': 507.512, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U507512.jpg'}, {'end': 706.108, 'src': 'embed', 'start': 683.133, 'weight': 3, 'content': [{'end': 693.461, 'text': 'So basically, as long as this communication is solid, as long as this keeps happening right, Computer 1 keeps sending out twice as much information.', 'start': 683.133, 'duration': 10.328}, {'end': 699.424, 'text': "So the next time it'll send out 8 packets, then it'll send out 16 packets, 32 packets, 64 packets.", 'start': 693.521, 'duration': 5.903}, {'end': 706.108, 'text': "And as long as it's receiving the acknowledgement on the last packet and that it's in order,", 'start': 699.844, 'duration': 6.264}], 'summary': 'Computer 1 sends out twice as much information each time, with packets increasing in powers of 2.', 'duration': 22.975, 'max_score': 683.133, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U683133.jpg'}, {'end': 846.421, 'src': 'embed', 'start': 808.952, 'weight': 4, 'content': [{'end': 814.376, 'text': "So, basically, every time there's a problem with the transmission, you go back computer,", 'start': 808.952, 'duration': 5.424}, {'end': 822.164, 'text': "one goes back to sending one packet and then it starts expanding the window and then, if there's a problem, it brings the window back down again.", 'start': 814.376, 'duration': 7.788}, {'end': 824.146, 'text': 'Starts expanding the window, brings it back down again.', 'start': 822.204, 'duration': 1.942}, {'end': 833.413, 'text': 'Now, If you were like me and you were using back the internet back when we had 56K modems and 28K modems and all that,', 'start': 824.566, 'duration': 8.847}, {'end': 835.815, 'text': 'you used to see this windowing a lot.', 'start': 833.413, 'duration': 2.402}, {'end': 840.918, 'text': "So if you're 30 years old or older, you've probably seen this happen.", 'start': 835.935, 'duration': 4.983}, {'end': 846.421, 'text': 'So back when you used to download information from websites, you would have a little progress bar.', 'start': 841.298, 'duration': 5.123}], 'summary': 'Transmission problems lead to window expansion and contraction, familiar to those who used 56k modems.', 'duration': 37.469, 'max_score': 808.952, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U808952.jpg'}], 'start': 452.372, 'title': 'Tcp windowing in tcp/ip', 'summary': "Emphasizes the importance of windowing in tcp, a vital process for data transmission from client to server, especially in scenarios of flaky communication lines. it also explains the tcp/ip windowing process, where data is broken down into packets and sent in groups, progressively increasing in size as long as the communication is solid, but reducing back to smaller packets if there's a problem in the transmission.", 'chapters': [{'end': 528.582, 'start': 452.372, 'title': 'Tcp windowing and its importance', 'summary': 'Emphasizes the importance of windowing in tcp, a vital process for data transmission from client to server, especially in scenarios of flaky communication lines, rooted in the military origins of tcp/ip.', 'duration': 76.21, 'highlights': ['TCP windowing is crucial for data transmission between client and server, especially in scenarios of flaky communication lines, rooted in the military origins of TCP/IP.', 'TCP/IP was created for military use, specifically for scenarios like nuclear Armageddon, emphasizing the importance of reliable communication in critical situations.', 'The process of windowing in TCP involves how data is sent from one computer to another, highlighting its significance in facilitating communication between computers.']}, {'end': 861.329, 'start': 529.042, 'title': 'Tcp/ip windowing process', 'summary': "Explains the tcp/ip windowing process, where data is broken down into packets and sent in groups, progressively increasing in size as long as the communication is solid, but reducing back to smaller packets if there's a problem in the transmission, with reference to the experience of using 56k modems and the visual representation of progress bars during downloads.", 'duration': 332.287, 'highlights': ['Computer 1 sends packets in groups, doubling in size as long as the communication is solid, e.g., sending 8, 16, 32, 64 packets, and so on.', "If there's a problem in the data transmission, Computer 1 reduces the window back to sending smaller packets, e.g., one packet, and gradually expands it again.", 'The experience of using 56K modems and the visual representation of progress bars during downloads demonstrate the TCP/IP windowing process.']}], 'duration': 408.957, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U452372.jpg', 'highlights': ['TCP/IP was created for military use, specifically for scenarios like nuclear Armageddon, emphasizing the importance of reliable communication in critical situations.', 'The process of windowing in TCP involves how data is sent from one computer to another, highlighting its significance in facilitating communication between computers.', 'TCP windowing is crucial for data transmission between client and server, especially in scenarios of flaky communication lines, rooted in the military origins of TCP/IP.', 'Computer 1 sends packets in groups, doubling in size as long as the communication is solid, e.g., sending 8, 16, 32, 64 packets, and so on.', "If there's a problem in the data transmission, Computer 1 reduces the window back to sending smaller packets, e.g., one packet, and gradually expands it again.", 'The experience of using 56K modems and the visual representation of progress bars during downloads demonstrate the TCP/IP windowing process.']}, {'end': 1253.056, 'segs': [{'end': 970.06, 'src': 'embed', 'start': 881.001, 'weight': 0, 'content': [{'end': 890.447, 'text': "56K modems? Why do I care about that? Why this is important in today's day and age is because of real-time communications.", 'start': 881.001, 'duration': 9.446}, {'end': 897.312, 'text': 'Because TCPIP version 4 can be a real mess for real-time communications.', 'start': 890.948, 'duration': 6.364}, {'end': 902.434, 'text': "Because that whole windowing process, when you're sending pictures, you probably don't notice it.", 'start': 897.372, 'duration': 5.062}, {'end': 904.295, 'text': 'if you have a broadband connection, you know.', 'start': 902.434, 'duration': 1.861}, {'end': 908.297, 'text': 'if you have a three megabit per second connection, you know, you just see.', 'start': 904.295, 'duration': 4.002}, {'end': 909.957, 'text': 'you just see videos download.', 'start': 908.297, 'duration': 1.66}, {'end': 911.518, 'text': 'you just see pictures download.', 'start': 909.957, 'duration': 1.561}, {'end': 917.04, 'text': "even if there are little quirks or little stops in it, it's still so fast you do not see it.", 'start': 911.518, 'duration': 5.522}, {'end': 921.042, 'text': 'real-time communication has to happen in real time.', 'start': 917.04, 'duration': 4.002}, {'end': 925.264, 'text': 'but the problem is is if there are any problems or hiccups on the network,', 'start': 921.042, 'duration': 4.222}, {'end': 934.603, 'text': 'With this windowing process you can have the sending computer go down to sending three, four, eight packets at a time.', 'start': 926.5, 'duration': 8.103}, {'end': 939.505, 'text': 'Eight packets is not enough to keep a real-time communication stream going.', 'start': 935.023, 'duration': 4.482}, {'end': 942.946, 'text': 'Again, this gets a little complicated for this class.', 'start': 940.405, 'duration': 2.541}, {'end': 947.268, 'text': 'The more you play with networking and such, the more you will understand this.', 'start': 943.166, 'duration': 4.102}, {'end': 954.833, 'text': 'The main thing to understand with the transmission control protocol is that this is what actually controls the communication.', 'start': 947.569, 'duration': 7.264}, {'end': 957.935, 'text': 'So IP connects two computers together.', 'start': 954.873, 'duration': 3.062}, {'end': 964.959, 'text': "TCP is what then deals with the communication between the computers once they've started talking to each other.", 'start': 958.355, 'duration': 6.604}, {'end': 970.06, 'text': 'The biggest concept out of TCP you have to understand though is this thing called windowing.', 'start': 965.339, 'duration': 4.721}], 'summary': 'Real-time communications depend on tcp windowing for smooth transmission, impacting network speed and quality.', 'duration': 89.059, 'max_score': 881.001, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U881001.jpg'}, {'end': 1175.292, 'src': 'heatmap', 'start': 1041.159, 'weight': 5, 'content': [{'end': 1047.644, 'text': 'IP addresses are addresses that are used to signify every computer or device on a network.', 'start': 1041.159, 'duration': 6.485}, {'end': 1052.86, 'text': 'every computer or device on a TCP IP version 4 network needs an IP address 10.1.', 'start': 1048.084, 'duration': 4.776}, {'end': 1052.89, 'text': '10.1 192.168.', 'start': 1052.86, 'duration': 0.03}, {'end': 1053.105, 'text': '1.1 etcetera 207.65.', 'start': 1052.89, 'duration': 0.215}, {'end': 1054.046, 'text': '44.1. these are all IP addresses.', 'start': 1053.105, 'duration': 0.941}, {'end': 1058.827, 'text': 'so every device on the network needs what is called an IP address.', 'start': 1054.046, 'duration': 4.781}, {'end': 1078.655, 'text': 'so then, After you have the IP address, you have something called the subnet mask.', 'start': 1058.827, 'duration': 19.828}, {'end': 1087.101, 'text': "Now, in the next section, we're going to talk a lot more about the subnet mask, so we're just going to kind of glaze over right here.", 'start': 1080.696, 'duration': 6.405}, {'end': 1098.22, 'text': 'The subnet mask is basically a way to segment a network logically,', 'start': 1089.431, 'duration': 8.789}, {'end': 1106.249, 'text': 'so that different computers and different devices cannot necessarily talk to other computers and devices on the same physical network.', 'start': 1098.22, 'duration': 8.029}, {'end': 1113.694, 'text': "So, basically, if you have a large network, let's say you have, I don't know, 200 computers on a network.", 'start': 1106.649, 'duration': 7.045}, {'end': 1119.475, 'text': "you don't necessarily want all those computers to be able to talk to each other, even though they're physically connected to the same network.", 'start': 1113.694, 'duration': 5.781}, {'end': 1125.136, 'text': 'You can prevent them from talking to each other by putting in this thing called a subnet mask.', 'start': 1119.995, 'duration': 5.141}, {'end': 1129.437, 'text': "And the subnet mask, again, like I said, we're going to talk about it in the next section a little bit.", 'start': 1125.196, 'duration': 4.241}, {'end': 1134.618, 'text': 'Now, the next thing after you deal with the subnet mask is something called the default gateway.', 'start': 1130.077, 'duration': 4.541}, {'end': 1145.108, 'text': 'The default gateway is the router for the sub network that you are on.', 'start': 1138.84, 'duration': 6.268}, {'end': 1156.321, 'text': "So basically what the default gateway allows is your computer is going to look on the local network for the computer or device that it's looking for.", 'start': 1145.489, 'duration': 10.832}, {'end': 1159.103, 'text': "Let's say it's looking for a website or it's looking for a server.", 'start': 1156.361, 'duration': 2.742}, {'end': 1161.745, 'text': "It's going to look at the local network first.", 'start': 1159.523, 'duration': 2.222}, {'end': 1166.067, 'text': "If it can't find that computer or device on the local network,", 'start': 1162.185, 'duration': 3.882}, {'end': 1175.292, 'text': 'it will then go to the default gateway and it will ask the default gateway to find that computer or device on whatever else is on the other side.', 'start': 1166.067, 'duration': 9.225}], 'summary': 'Ip addresses, subnet masks, and default gateways are crucial for managing network connectivity and security.', 'duration': 65.09, 'max_score': 1041.159, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U1041159.jpg'}, {'end': 1263.918, 'src': 'embed', 'start': 1234.247, 'weight': 7, 'content': [{'end': 1239.509, 'text': "You know, if you're dealing with small networks, this will be the router, this will be the DSL modem, this will be the cable modem,", 'start': 1234.247, 'duration': 5.262}, {'end': 1240.99, 'text': 'this will be the ADTRAN, etc.', 'start': 1239.509, 'duration': 1.481}, {'end': 1247.613, 'text': 'Basically, the default gateway is what connects your subnetwork to all the other networks that are out there.', 'start': 1241.37, 'duration': 6.243}, {'end': 1253.056, 'text': 'So you understand what the default gateway is.', 'start': 1249.034, 'duration': 4.022}, {'end': 1263.918, 'text': 'Now, the next big thing to understand is we were just talking about www.cnn.com.', 'start': 1253.176, 'duration': 10.742}], 'summary': "Understanding the default gateway's role in connecting subnetworks to external networks is key to networking.", 'duration': 29.671, 'max_score': 1234.247, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U1234247.jpg'}], 'start': 861.65, 'title': 'Tcp/ip network components', 'summary': 'Provides an overview of tcp/ip network components, highlighting the need for an ip address for every device and the function of a default gateway in connecting subnetworks to external networks.', 'chapters': [{'end': 986.926, 'start': 861.65, 'title': 'Importance of windowing in real-time communication', 'summary': "Emphasizes the importance of windowing in real-time communications, particularly in tcp/ip version 4, as it controls the communication and ensures seamless data transfer, highlighting the impact on real-time communication quality and the significance in today's day and age.", 'duration': 125.276, 'highlights': ['The windowing process in TCP controls the communication between computers and ensures seamless data transfer, crucial for real-time communications and quality. (Relevance: 5)', 'TCP/IP version 4 can be problematic for real-time communications due to the windowing process, impacting the quality of real-time communication streams. (Relevance: 4)', 'Real-time communication requires data to be transferred in real time, and any hiccups in the network can lead to the sending computer reducing the number of packets sent at a time, impacting the communication stream. (Relevance: 3)', 'Windowing involves the doubling of packets until a problem occurs, and then it adjusts the packet size to maintain seamless data transfer, illustrating its critical role in ensuring efficient communication. (Relevance: 2)', 'The transmission control protocol (TCP) is crucial in controlling communication between computers, with the windowing process being a significant concept to comprehend, as it dictates the data transfer mechanism. (Relevance: 1)']}, {'end': 1253.056, 'start': 986.926, 'title': 'Tcp/ip network components', 'summary': 'Provides an overview of tcp/ip network components including ip addresses, subnet masks, and default gateways, emphasizing the need for an ip address for every device and the function of a default gateway in connecting subnetworks to external networks.', 'duration': 266.13, 'highlights': ['IP addresses are used to signify every computer or device on a network, such as 10.1.10.1, 192.168.1.1, or 207.65.44.1. Emphasizes the significance of IP addresses as unique identifiers for devices on a network.', 'Subnet mask segments a network logically to prevent communication between different computers and devices on the same physical network. Highlights the purpose of a subnet mask in logically segmenting a network to control communication between devices.', 'Default gateway serves as the router for the subnetwork and enables devices to access external networks by forwarding requests beyond the local network. Explains the role of the default gateway in enabling devices to access external networks by forwarding requests beyond the local network.']}], 'duration': 391.406, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U861650.jpg', 'highlights': ['The windowing process in TCP controls the communication between computers and ensures seamless data transfer, crucial for real-time communications and quality.', 'TCP/IP version 4 can be problematic for real-time communications due to the windowing process, impacting the quality of real-time communication streams.', 'Real-time communication requires data to be transferred in real time, and any hiccups in the network can lead to the sending computer reducing the number of packets sent at a time, impacting the communication stream.', 'Windowing involves the doubling of packets until a problem occurs, and then it adjusts the packet size to maintain seamless data transfer, illustrating its critical role in ensuring efficient communication.', 'The transmission control protocol (TCP) is crucial in controlling communication between computers, with the windowing process being a significant concept to comprehend, as it dictates the data transfer mechanism.', 'IP addresses are used to signify every computer or device on a network, such as 10.1.10.1, 192.168.1.1, or 207.65.44.1. Emphasizes the significance of IP addresses as unique identifiers for devices on a network.', 'Subnet mask segments a network logically to prevent communication between different computers and devices on the same physical network. Highlights the purpose of a subnet mask in logically segmenting a network to control communication between devices.', 'Default gateway serves as the router for the subnetwork and enables devices to access external networks by forwarding requests beyond the local network. Explains the role of the default gateway in enabling devices to access external networks by forwarding requests beyond the local network.']}, {'end': 1661.409, 'segs': [{'end': 1548.318, 'src': 'heatmap', 'start': 1474.722, 'weight': 0, 'content': [{'end': 1478.826, 'text': 'Once we get into website administration and all that, this gets a little more complicated.', 'start': 1474.722, 'duration': 4.104}, {'end': 1480.748, 'text': 'But this is the basic idea.', 'start': 1479.266, 'duration': 1.482}, {'end': 1483.411, 'text': 'Your computer does not care about domain names.', 'start': 1481.068, 'duration': 2.343}, {'end': 1485.493, 'text': 'It resolves domain names.', 'start': 1483.811, 'duration': 1.682}, {'end': 1494.55, 'text': 'through DNS, a domain name server, to get the IP address of the computer with this domain name and then, once it has the IP address,', 'start': 1486.544, 'duration': 8.006}, {'end': 1497.913, 'text': 'it then goes out to communicate with that computer.', 'start': 1494.55, 'duration': 3.363}, {'end': 1508.402, 'text': 'Now the final component that you need to understand about for TCP IP networks is something called DHCP.', 'start': 1498.894, 'duration': 9.508}, {'end': 1513.416, 'text': "I think it's Dynamic Host Control Protocol.", 'start': 1510.213, 'duration': 3.203}, {'end': 1519.361, 'text': "Now, what is this? Well, as I've said, every device on the network needs an IP address.", 'start': 1513.756, 'duration': 5.605}, {'end': 1522.484, 'text': "If it does not have an IP address, it can't do anything.", 'start': 1519.401, 'duration': 3.083}, {'end': 1526.848, 'text': 'Not only can it not receive communications, but it also cannot talk to everybody.', 'start': 1522.584, 'duration': 4.264}, {'end': 1532.41, 'text': 'So every computer on the network needs to know its IP address, it needs to know its subnet mask,', 'start': 1527.248, 'duration': 5.162}, {'end': 1537.693, 'text': 'it needs to know its default gateway and it needs to know what DNS servers to talk to.', 'start': 1532.41, 'duration': 5.283}, {'end': 1542.175, 'text': 'So, there are two ways you can give this information to the computer.', 'start': 1538.153, 'duration': 4.022}, {'end': 1548.318, 'text': 'The first is by giving your computer what is called a static IP address.', 'start': 1542.495, 'duration': 5.823}], 'summary': 'Tcp/ip networks involve dns, ip addresses, and dhcp for communication and network configuration.', 'duration': 52.126, 'max_score': 1474.722, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U1474722.jpg'}, {'end': 1636.937, 'src': 'embed', 'start': 1611.691, 'weight': 2, 'content': [{'end': 1619.854, 'text': 'if you accidentally give two devices or two computers the exact same IP address, it can just cause all kinds of havoc.', 'start': 1611.691, 'duration': 8.163}, {'end': 1623.334, 'text': 'So some packets go to that computer, some packets go to that computer.', 'start': 1620.154, 'duration': 3.18}, {'end': 1628.292, 'text': "I'm not saying some documents go to one computer and some documents go to the other computer.", 'start': 1623.474, 'duration': 4.818}, {'end': 1636.937, 'text': 'Like I said, when computers are communicating using a TCPIP protocol, things like documents, things like videos,', 'start': 1628.612, 'duration': 8.325}], 'summary': 'Duplicate ip addresses can cause communication issues.', 'duration': 25.246, 'max_score': 1611.691, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U1611691.jpg'}], 'start': 1253.176, 'title': 'Tcp/ip networking basics', 'summary': 'Explains the role of dns servers in mapping domain names to ip addresses, the importance of dhcp in assigning ip addresses to devices, and the need for unique ip addresses to avoid network conflicts and communication issues.', 'chapters': [{'end': 1661.409, 'start': 1253.176, 'title': 'Tcp/ip networking basics', 'summary': 'Explains the role of dns servers in mapping domain names to ip addresses, the importance of dhcp in assigning ip addresses to devices, and the need for unique ip addresses to avoid network conflicts and communication issues.', 'duration': 408.233, 'highlights': ['DNS servers map domain names to IP addresses, enabling communication between devices and websites. DNS servers play a crucial role in connecting domain names like www.cnn.com to their corresponding IP addresses, facilitating effective communication between devices and websites.', 'DHCP is essential for assigning IP addresses, subnet masks, default gateways, and DNS servers to devices on a network. DHCP ensures that every device on a network receives vital network configuration details, such as IP addresses, subnet masks, default gateways, and DNS servers, facilitating seamless communication and connectivity.', 'Unique IP addresses are crucial to prevent network conflicts and ensure efficient communication between devices. The importance of unique IP addresses is emphasized to avoid network conflicts and ensure the smooth transmission of data and communication between devices on a TCP/IP network.']}], 'duration': 408.233, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U1253176.jpg', 'highlights': ['DNS servers play a crucial role in connecting domain names to IP addresses, facilitating effective communication between devices and websites.', 'DHCP ensures that every device on a network receives vital network configuration details, such as IP addresses, subnet masks, default gateways, and DNS servers, facilitating seamless communication and connectivity.', 'The importance of unique IP addresses is emphasized to avoid network conflicts and ensure the smooth transmission of data and communication between devices on a TCP/IP network.']}, {'end': 2055.967, 'segs': [{'end': 1775.903, 'src': 'embed', 'start': 1711.099, 'weight': 0, 'content': [{'end': 1721.088, 'text': 'So basically DHCP allows for the automatic distribution of IP addresses in the information, like I say, subnet masks, default gateways, DNS, etc.', 'start': 1711.099, 'duration': 9.989}, {'end': 1722.309, 'text': 'This is a very good thing.', 'start': 1721.128, 'duration': 1.181}, {'end': 1728.394, 'text': 'Again, you may not realize it on a 5 or 10 computer network, but once you start dealing with hundreds or thousands of computers,', 'start': 1722.849, 'duration': 5.545}, {'end': 1731.856, 'text': 'this is DHCP is a lifesaver.', 'start': 1728.394, 'duration': 3.462}, {'end': 1736.019, 'text': 'Now what happens in the DHCP process?', 'start': 1732.216, 'duration': 3.803}, {'end': 1739.093, 'text': 'is that Your computer?', 'start': 1736.019, 'duration': 3.074}, {'end': 1746.783, 'text': 'so we put your computer here again calls out to the DHCP server and it says hey, I need an IP address.', 'start': 1739.093, 'duration': 7.69}, {'end': 1756.522, 'text': 'So you have configured in the DHCP server what the scope of IP addresses the DHCP server can give out.', 'start': 1747.523, 'duration': 8.999}, {'end': 1761.338, 'text': 'So you will tell the DHCP server, you can give out IP addresses 192.168.', 'start': 1756.542, 'duration': 4.796}, {'end': 1769.699, 'text': '100 through 254.', 'start': 1761.338, 'duration': 8.361}, {'end': 1775.903, 'text': 'So this gives a scope of 154 IP addresses that this DHCP server can give out.', 'start': 1769.699, 'duration': 6.204}], 'summary': 'Dhcp automates ip address distribution, handling hundreds or thousands of computers efficiently, providing a scope of 154 ip addresses.', 'duration': 64.804, 'max_score': 1711.099, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U1711099.jpg'}, {'end': 1935.587, 'src': 'embed', 'start': 1903.865, 'weight': 2, 'content': [{'end': 1910.211, 'text': 'And then the lease is renewed for another four days and the computer keeps the IP address for four days.', 'start': 1903.865, 'duration': 6.346}, {'end': 1918.738, 'text': 'Again, at the 50% mark, the computer then contacts the DHCP server again and says, hey, I still like this IP address.', 'start': 1910.811, 'duration': 7.927}, {'end': 1921.52, 'text': 'Am I allowed to keep it? DHCP server says yes or no.', 'start': 1918.878, 'duration': 2.642}, {'end': 1924.002, 'text': 'Well, what happens is if.', 'start': 1922.281, 'duration': 1.721}, {'end': 1935.587, 'text': 'your computer cannot contact the DHCP server at the 50% mark then it waits until the next 50% mark.', 'start': 1926.167, 'duration': 9.42}], 'summary': 'Lease renewed for 4 days, computer contacts dhcp server at 50% mark to keep ip address.', 'duration': 31.722, 'max_score': 1903.865, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U1903865.jpg'}], 'start': 1662.129, 'title': 'Dhcp and ip address distribution', 'summary': 'Covers the importance of dhcp for automatic distribution of ip addresses, subnet masks, default gateways, and dns servers, crucial for large networks. it also explains the dhcp lease renewal process, where computers attempt to renew the lease at the 50% mark of the lease period.', 'chapters': [{'end': 1823.749, 'start': 1662.129, 'title': 'Automatic ip address distribution', 'summary': 'Explains the importance of dhcp for automatic distribution of ip addresses, subnet masks, default gateways, and dns servers, which is especially crucial for large networks with hundreds or thousands of computers.', 'duration': 161.62, 'highlights': ['DHCP allows for the automatic distribution of IP addresses, subnet masks, default gateways, and DNS servers, which is crucial for large networks with hundreds or thousands of computers. DHCP enables automatic distribution of IP addresses, subnet masks, default gateways, and DNS servers, which is essential for large networks.', 'The DHCP server can give out a scope of 154 IP addresses within the specified range, ensuring efficient allocation of addresses. The DHCP server can allocate a scope of 154 IP addresses within the specified range, ensuring efficient address allocation.', 'Configuring the DHCP server includes specifying the scope of IP addresses, subnet mask, default gateway, and DNS servers to be distributed to the computers on the network. Configuring the DHCP server involves specifying the scope of IP addresses, subnet mask, default gateway, and DNS servers to be distributed to network computers.']}, {'end': 2055.967, 'start': 1824.249, 'title': 'Dhcp lease renewal process', 'summary': 'Explains the dhcp lease renewal process, where the dhcp server assigns ip addresses and lease times to computers, and at 50% mark of the lease period, computers attempt to renew the lease by contacting the dhcp server.', 'duration': 231.718, 'highlights': ['DHCP server assigns IP addresses and lease times to computers The DHCP server assigns IP addresses and lease times to computers based on the configuration set by the system administrator.', 'Computers attempt to renew the lease at 50% mark of the lease period At the 50% mark of the lease period, computers automatically attempt to contact the DHCP server to renew the lease for the assigned IP address.', 'Lease time can be configured by the system administrator System administrators have the flexibility to configure the lease time for IP addresses, which can range from a day to a year, based on their preferences.']}], 'duration': 393.838, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U1662129.jpg', 'highlights': ['DHCP enables automatic distribution of IP addresses, subnet masks, default gateways, and DNS servers, crucial for large networks.', 'The DHCP server can give out a scope of 154 IP addresses within the specified range, ensuring efficient allocation of addresses.', 'Computers attempt to renew the lease at 50% mark of the lease period.', 'Configuring the DHCP server involves specifying the scope of IP addresses, subnet mask, default gateway, and DNS servers to be distributed to network computers.']}, {'end': 2548.629, 'segs': [{'end': 2100.728, 'src': 'embed', 'start': 2074.434, 'weight': 0, 'content': [{'end': 2080.717, 'text': 'What you have to understand is, once you get into more complicated networking, is the shorter your DHCP lease,', 'start': 2074.434, 'duration': 6.283}, {'end': 2087.016, 'text': 'The more network traffic you have just for stupid things like DHCP.', 'start': 2082.813, 'duration': 4.203}, {'end': 2093.442, 'text': 'but it means that less IP addresses are being used by computers that may not be on the network.', 'start': 2087.016, 'duration': 6.426}, {'end': 2100.728, 'text': 'Whereas the longer the IP address, the more IP addresses get used up, but the less traffic on the network.', 'start': 2093.762, 'duration': 6.966}], 'summary': 'Shorter dhcp leases lead to more network traffic, longer leases use more ip addresses.', 'duration': 26.294, 'max_score': 2074.434, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U2074434.jpg'}, {'end': 2175.397, 'src': 'embed', 'start': 2145.793, 'weight': 2, 'content': [{'end': 2150.594, 'text': 'Your printer, your network printer would need an IP address that was unique to the world, etc.', 'start': 2145.793, 'duration': 4.801}, {'end': 2158.737, 'text': 'Because they thought every single device that was connected to the internet would need its own unique IP address.', 'start': 2150.654, 'duration': 8.083}, {'end': 2163.199, 'text': 'Well then they came up with something called NAT or Network Address Translation.', 'start': 2159.037, 'duration': 4.162}, {'end': 2166.1, 'text': 'And this fixed a whole bunch of stuff.', 'start': 2163.619, 'duration': 2.481}, {'end': 2168.881, 'text': 'So you will see, this is our router.', 'start': 2166.52, 'duration': 2.361}, {'end': 2175.397, 'text': 'that most internal networks have IP address ranges in the 192.168.', 'start': 2170.407, 'duration': 4.99}], 'summary': 'Nat solved the issue of unique ip addresses for every connected device, with most internal networks using the 192.168 ip address range.', 'duration': 29.604, 'max_score': 2145.793, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U2145793.jpg'}, {'end': 2441.274, 'src': 'embed', 'start': 2399.126, 'weight': 3, 'content': [{'end': 2402.386, 'text': "maybe you should go on google or wikipedia if it's a little confusing.", 'start': 2399.126, 'duration': 3.26}, {'end': 2407.328, 'text': 'the main thing that you have to understand that nat does network address translation is.', 'start': 2402.386, 'duration': 4.942}, {'end': 2408.548, 'text': 'it makes it so.', 'start': 2407.328, 'duration': 1.22}, {'end': 2416.892, 'text': 'every single device that can talk on the internet does not need its own absolute, unique IP address in the entire world.', 'start': 2408.548, 'duration': 8.344}, {'end': 2425.82, 'text': 'If NAT did not exist, then literally every single device that connected to the internet would need its own IP address,', 'start': 2417.372, 'duration': 8.448}, {'end': 2428.643, 'text': 'and simply there are not enough IP addresses out there.', 'start': 2425.82, 'duration': 2.823}, {'end': 2431.125, 'text': "So, with this, we've talked about the IP address.", 'start': 2429.103, 'duration': 2.022}, {'end': 2439.132, 'text': 'Every single computer or device on a TCP IP version 4 network needs an IP address, both to send and receive information.', 'start': 2431.365, 'duration': 7.767}, {'end': 2441.274, 'text': 'We talked about the subnet mask.', 'start': 2439.592, 'duration': 1.682}], 'summary': 'Nat enables sharing ip addresses, preventing ip address exhaustion.', 'duration': 42.148, 'max_score': 2399.126, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U2399126.jpg'}, {'end': 2509.338, 'src': 'heatmap', 'start': 2461.946, 'weight': 1, 'content': [{'end': 2465.847, 'text': 'the default gateway or router is what separates those two networks.', 'start': 2461.946, 'duration': 3.901}, {'end': 2467.127, 'text': 'We talked about DNS.', 'start': 2466.127, 'duration': 1}, {'end': 2472.369, 'text': 'Remember, domain names, cnn.com, facebook.com, yahoo.com, etc.', 'start': 2467.308, 'duration': 5.061}, {'end': 2476.131, 'text': "don't mean anything to your computer.", 'start': 2473.209, 'duration': 2.922}, {'end': 2482.056, 'text': 'your computer will go out and talk to a DNS server and all say hey, my user gave me this name.', 'start': 2476.131, 'duration': 5.925}, {'end': 2483.117, 'text': 'what do I do with it?', 'start': 2482.056, 'duration': 1.061}, {'end': 2488.613, 'text': 'that DNS server will then say IP address for that domain name.', 'start': 2483.117, 'duration': 5.496}, {'end': 2492.113, 'text': 'is this 208.77..', 'start': 2488.613, 'duration': 3.5}, {'end': 2494.414, 'text': '66.4 That gets given back to your computer.', 'start': 2492.113, 'duration': 2.301}, {'end': 2500.196, 'text': 'Your computer then tries to communicate with the website or the computer based upon that IP address.', 'start': 2494.674, 'duration': 5.522}, {'end': 2503.737, 'text': 'We then talked about DHCP, Dynamic Host Control Protocol.', 'start': 2500.496, 'duration': 3.241}, {'end': 2509.338, 'text': 'Again, you can plug in what are called static IP addresses into every single computer and device on your network.', 'start': 2504.177, 'duration': 5.161}], 'summary': 'The default gateway separates networks, dns translates domain names to ip addresses, and dhcp assigns dynamic ip addresses.', 'duration': 47.392, 'max_score': 2461.946, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U2461946.jpg'}], 'start': 2055.967, 'title': 'Dhcp, leases, nat, and nat significance', 'summary': 'Explores dhcp leases, highlighting the impact of lease duration on network traffic and ip address conservation. it also explains the significance of network address translation (nat) in enabling multiple devices to communicate over the internet using a single unique ip address, preventing address exhaustion and simplifying network management.', 'chapters': [{'end': 2122.001, 'start': 2055.967, 'title': 'Understanding dhcp, leases, and nat', 'summary': 'Explores the significance of dhcp leases, emphasizing that shorter leases increase network traffic but conserve ip addresses, while longer leases lead to lower network traffic but consume more ip addresses. additionally, it introduces the concept of network address translation (nat).', 'duration': 66.034, 'highlights': ['DHCP leases: Shorter leases lead to increased network traffic but conserve IP addresses, while longer leases result in lower network traffic but consume more IP addresses.', 'Network address translation (NAT): Introduction of the concept and its significance in networking.']}, {'end': 2548.629, 'start': 2122.581, 'title': 'Network address translation and its significance', 'summary': 'Explains the concept of network address translation (nat) and its crucial role in allowing multiple devices to communicate over the internet using a single unique ip address, thus preventing ip address exhaustion and simplifying network management.', 'duration': 426.048, 'highlights': ['NAT allows multiple devices to communicate over the internet using a single unique IP address NAT enables multiple devices within a network to share a single unique IP address for communication over the internet, preventing the need for every device to have its own unique IP address.', 'NAT prevents IP address exhaustion NAT prevents the exhaustion of available IP addresses by allowing multiple devices within a network to share a single unique IP address for external communication, thereby conserving the limited pool of available IP addresses.', 'NAT simplifies network management NAT simplifies network management by allowing multiple devices within a network to use private IP addresses for internal communication, reducing the complexity of managing a large number of unique public IP addresses.']}], 'duration': 492.662, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U2055967.jpg', 'highlights': ['Shorter DHCP leases increase network traffic but conserve IP addresses', 'Longer DHCP leases reduce network traffic but consume more IP addresses', 'Network address translation (NAT) enables multiple devices to share a single unique IP address for internet communication', 'NAT prevents IP address exhaustion by allowing multiple devices to share a single unique IP address', 'NAT simplifies network management by allowing multiple devices to use private IP addresses for internal communication']}, {'end': 3068.857, 'segs': [{'end': 2894.896, 'src': 'embed', 'start': 2865.709, 'weight': 3, 'content': [{'end': 2869.571, 'text': 'These octets are made up of eight bits.', 'start': 2865.709, 'duration': 3.862}, {'end': 2874.212, 'text': "The bits are either on or they're off, so 1 or 0.", 'start': 2870.051, 'duration': 4.161}, {'end': 2886.194, 'text': 'The way you come up with a number is, again, from right to left, you start with 1, then you double to 2, to 4, to 8, to 16, to 32, to 64, to 128.', 'start': 2874.212, 'duration': 11.982}, {'end': 2894.896, 'text': 'So all this will make a little bit more sense once we get into the subnet mask in a second, but this is the basic idea behind numbering and octets.', 'start': 2886.194, 'duration': 8.702}], 'summary': 'Octets consist of 8 bits, which are either on or off (1 or 0), and are used to represent numbers in a binary system.', 'duration': 29.187, 'max_score': 2865.709, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U2865709.jpg'}, {'end': 3001.321, 'src': 'embed', 'start': 2968.949, 'weight': 0, 'content': [{'end': 2983.589, 'text': '255.0 This subnet mask tells you what part of this IP address is the network identifier and what part of this IP address is the device identifier.', 'start': 2968.949, 'duration': 14.64}, {'end': 2991.495, 'text': 'Now, this is very, very important because devices on different networks cannot talk to each other.', 'start': 2983.93, 'duration': 7.565}, {'end': 3001.321, 'text': 'So if you have one computer plugged into a switch on network one and you have a printer plugged into the exact same switch,', 'start': 2991.915, 'duration': 9.406}], 'summary': 'Subnet mask identifies network and device parts of ip address.', 'duration': 32.372, 'max_score': 2968.949, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U2968949.jpg'}, {'end': 3053.749, 'src': 'embed', 'start': 3028.757, 'weight': 1, 'content': [{'end': 3035.981, 'text': 'So if you have a computer on one network and a printer on a different network, they need a router to communicate.', 'start': 3028.757, 'duration': 7.224}, {'end': 3039.543, 'text': "even if they're plugged in physically to the same switch.", 'start': 3036.321, 'duration': 3.222}, {'end': 3041.163, 'text': 'So this is very important to understand.', 'start': 3039.623, 'duration': 1.54}, {'end': 3048.546, 'text': 'So you can have multiple subnets, multiple networks, all plugged into the same physical switch.', 'start': 3041.623, 'duration': 6.923}, {'end': 3050.027, 'text': 'And this is not VLANs.', 'start': 3048.627, 'duration': 1.4}, {'end': 3053.749, 'text': "This isn't like Cisco VLANs or like routing or switching VLANs.", 'start': 3050.047, 'duration': 3.702}], 'summary': 'Routers are needed for communication between devices on different networks, even if physically connected to the same switch.', 'duration': 24.992, 'max_score': 3028.757, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U3028757.jpg'}], 'start': 2549.009, 'title': 'Understanding subnet masking', 'summary': 'Explains the concept of subnet masking and its importance in identifying network and device identifiers within an ip address. it also highlights the role of routers in connecting different subnets. it illustrates how ip addresses are composed and the crucial numerical values derived for subnet masking.', 'chapters': [{'end': 2894.896, 'start': 2549.009, 'title': 'Understanding subnet masking', 'summary': 'Explains the concept of subnet masking, illustrating how ip addresses are composed of four separate octets, each made up of eight bits that can be either on or off, and how these bits are used to derive the numerical values, which will be crucial in subnet masking.', 'duration': 345.887, 'highlights': ['IP addresses are composed of four separate octets, each made up of eight bits that can be either on or off, and are used to derive the numerical values. This is essential to understand the structure of IP addresses and how they are composed of four separate octets, each consisting of eight bits that can be either on or off, and how these bits are used to derive the numerical values.', 'The numerical values for the octets are derived from right to left, starting with 1 and doubling successively to 128. The numerical values for the octets are derived from right to left, starting with 1 and doubling successively to 128, which is crucial in understanding how the numbers are assigned to the bits in the octets.', "These numerical values are crucial in subnet masking, which will be discussed further in the chapter. The numerical values derived from the octets' bits are crucial in subnet masking, which will be discussed further in the chapter, indicating the importance of understanding this concept for future topics."]}, {'end': 3068.857, 'start': 2901.055, 'title': 'Understanding subnet masking', 'summary': 'Explains how subnet masking works, emphasizing the importance of subnet masks in identifying network and device identifiers within an ip address, and highlighting the role of routers in connecting different subnets.', 'duration': 167.802, 'highlights': ['The subnet mask (e.g., 255.255.255.0) determines the network identifier and device identifier within an IP address, critical for devices on different networks to communicate.', 'Routers are essential for connecting devices on different subnets or networks, even if they are physically connected to the same switch.', 'The IP address serves as an identifier for both the networking device and the subnet, highlighting the significance of subnet masking in distinguishing between the two.', 'Devices on different subnets cannot communicate without a router, emphasizing the practical implications of subnet masking in network communication.', 'Understanding subnet masking is crucial as it enables the coexistence of multiple subnets and networks within the same physical switch, without requiring VLANs or complex routing and switching setups.']}], 'duration': 519.848, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U2549009.jpg', 'highlights': ['The subnet mask (e.g., 255.255.255.0) determines the network identifier and device identifier within an IP address, critical for devices on different networks to communicate.', 'Routers are essential for connecting devices on different subnets or networks, even if they are physically connected to the same switch.', 'Understanding subnet masking is crucial as it enables the coexistence of multiple subnets and networks within the same physical switch, without requiring VLANs or complex routing and switching setups.', 'IP addresses are composed of four separate octets, each made up of eight bits that can be either on or off, and are used to derive the numerical values.']}, {'end': 4168.932, 'segs': [{'end': 3181.061, 'src': 'embed', 'start': 3158.636, 'weight': 1, 'content': [{'end': 3168.521, 'text': 'what we do is using these octets, we decide how many networks we need in our network, in our overall network,', 'start': 3158.636, 'duration': 9.885}, {'end': 3178.437, 'text': 'and how many hosts we need in our overall network, and then all we do is we use that many bits that we need to accomplish our task.', 'start': 3168.521, 'duration': 9.916}, {'end': 3181.061, 'text': 'So we just divide it off anywhere in here.', 'start': 3178.517, 'duration': 2.544}], 'summary': 'Using octets to determine network and host requirements and allocate necessary bits.', 'duration': 22.425, 'max_score': 3158.636, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U3158636.jpg'}, {'end': 3315.028, 'src': 'embed', 'start': 3276.657, 'weight': 3, 'content': [{'end': 3278.418, 'text': 'So this is a class C subnet.', 'start': 3276.657, 'duration': 1.761}, {'end': 3288.344, 'text': 'So it would be two to the eighth minus two, and I just know this by heart, which comes out to 254 hosts.', 'start': 3278.799, 'duration': 9.545}, {'end': 3297.67, 'text': "So what you're doing when you're creating the subnet is you have to figure out either how many networks you want or how many hosts you want, and then,", 'start': 3288.865, 'duration': 8.805}, {'end': 3301.472, 'text': 'depending, you basically count one way or the other.', 'start': 3297.67, 'duration': 3.802}, {'end': 3315.028, 'text': 'if you need lots of networks, then you count out how many bits you need from left to right, and then You just take those bits for your subnet network.', 'start': 3301.472, 'duration': 13.556}], 'summary': 'Class c subnet with 254 hosts, determining subnet based on networks or hosts.', 'duration': 38.371, 'max_score': 3276.657, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U3276657.jpg'}, {'end': 3840.894, 'src': 'embed', 'start': 3817.777, 'weight': 2, 'content': [{'end': 3825.024, 'text': "the most important thing to take out of this is, if you have computers on two different TCPIP subnets, They can't talk to each other,", 'start': 3817.777, 'duration': 7.247}, {'end': 3830.667, 'text': "even if they're connected to a physical switch, unless you put a router in there and you do some configurations.", 'start': 3825.024, 'duration': 5.643}, {'end': 3835.23, 'text': "So if you understand that, at least it's an introduction to subnetting.", 'start': 3830.868, 'duration': 4.362}, {'end': 3840.894, 'text': "And I don't know, watch this five or six times in a row, and hopefully you'll get everything.", 'start': 3835.811, 'duration': 5.083}], 'summary': "Computers on different tcpip subnets can't communicate without a router and configurations.", 'duration': 23.117, 'max_score': 3817.777, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U3817777.jpg'}, {'end': 3997.188, 'src': 'embed', 'start': 3968.428, 'weight': 0, 'content': [{'end': 3971.49, 'text': 'We talked about all the components of the TCP IP networks.', 'start': 3968.428, 'duration': 3.062}, {'end': 3979.496, 'text': 'You have your IP address, you have your subnet mask which divides the computers into different subnets on the same physical network.', 'start': 3971.53, 'duration': 7.966}, {'end': 3982.578, 'text': 'We talked about DNS and default gateways.', 'start': 3979.756, 'duration': 2.822}, {'end': 3988.502, 'text': 'Default gateways are basically the router that connects your little subnet to other subnets.', 'start': 3982.618, 'duration': 5.884}, {'end': 3994.226, 'text': 'DNS is what turns domain names into IP addresses.', 'start': 3988.902, 'duration': 5.324}, {'end': 3997.188, 'text': 'Remember, your computer does not care about the domain name.', 'start': 3994.286, 'duration': 2.902}], 'summary': 'Tcp/ip components include ip, subnet mask, dns, default gateways.', 'duration': 28.76, 'max_score': 3968.428, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U3968428.jpg'}, {'end': 4067.507, 'src': 'embed', 'start': 4015.699, 'weight': 6, 'content': [{'end': 4018.64, 'text': 'That lease, again, maybe one day, year, whatever you decide.', 'start': 4015.699, 'duration': 2.941}, {'end': 4024.402, 'text': 'At the 50% mark, when that lease has 50% expired, the computer will try to renew the lease.', 'start': 4019.04, 'duration': 5.362}, {'end': 4030.605, 'text': "If it can't renew the lease, it'll go from 50% of that mark, 50% of that mark, 50% of that mark, etc.", 'start': 4024.463, 'duration': 6.142}, {'end': 4033.266, 'text': 'We talked about NAT, Network Address Translation.', 'start': 4030.965, 'duration': 2.301}, {'end': 4037.112, 'text': 'Again, just a bit of a confusing subject, sit down and read about it a little bit.', 'start': 4033.386, 'duration': 3.726}, {'end': 4038.575, 'text': "It's not that big a deal.", 'start': 4037.453, 'duration': 1.122}, {'end': 4047.184, 'text': 'Basically, what NAT allows is it allows IP addresses to be reused by internal networks.', 'start': 4039.056, 'duration': 8.128}, {'end': 4056.385, 'text': 'So like I say, my building, everymanit.com, inside we can have IP addresses 192.168.', 'start': 4047.324, 'duration': 9.061}, {'end': 4059.076, 'text': '1.3 and 192.168.', 'start': 4056.385, 'duration': 2.691}, {'end': 4059.566, 'text': '1.4, etc.', 'start': 4059.076, 'duration': 0.49}, {'end': 4063.386, 'text': 'And you can use those exact same IP addresses.', 'start': 4059.946, 'duration': 3.44}, {'end': 4067.507, 'text': 'If NAT, Network Address Translation, did not exist, that would not be possible.', 'start': 4063.566, 'duration': 3.941}], 'summary': 'Leases renew at 50% expiration; nat enables ip address reuse for internal networks.', 'duration': 51.808, 'max_score': 4015.699, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U4015699.jpg'}, {'end': 4136.051, 'src': 'embed', 'start': 4091.523, 'weight': 5, 'content': [{'end': 4093.025, 'text': 'we talked about subnet masking.', 'start': 4091.523, 'duration': 1.502}, {'end': 4098.889, 'text': 'we talked about, uh, what used to be called class full networks a, b, c, d and e.', 'start': 4093.025, 'duration': 5.864}, {'end': 4102.27, 'text': "um, Those really haven't been used since, like 1992 or something.", 'start': 4098.889, 'duration': 3.381}, {'end': 4103.832, 'text': 'They were replaced.', 'start': 4103.011, 'duration': 0.821}, {'end': 4108.154, 'text': 'That whole concept was replaced by CIDR, Classless Internet Domain Routing.', 'start': 4104.252, 'duration': 3.902}, {'end': 4110.595, 'text': "Again, at this level, don't worry about it.", 'start': 4108.274, 'duration': 2.321}, {'end': 4111.376, 'text': "That's a Cisco.", 'start': 4110.615, 'duration': 0.761}, {'end': 4115.138, 'text': "When you're going off your CCNA, start worrying about it then.", 'start': 4111.395, 'duration': 3.743}, {'end': 4119.68, 'text': "I just want you to have heard about this since you're dealing with TCP IP.", 'start': 4115.158, 'duration': 4.522}, {'end': 4124.182, 'text': 'Classful networks in CIDR, you should at least know those concepts exist.', 'start': 4120, 'duration': 4.182}, {'end': 4129.305, 'text': 'I showed you how to do the subnetting, how to find how many hosts would be on a subnet.', 'start': 4124.522, 'duration': 4.783}, {'end': 4134.43, 'text': 'and how many subnets would be on a subnet.', 'start': 4129.925, 'duration': 4.505}, {'end': 4136.051, 'text': "That's all just basic math.", 'start': 4134.45, 'duration': 1.601}], 'summary': 'Discussed subnet masking, classful networks, cidr, and basic subnetting with host and subnet calculations.', 'duration': 44.528, 'max_score': 4091.523, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U4091523.jpg'}], 'start': 3069.318, 'title': 'Tcp ip networks', 'summary': 'Covers subnet masking, subnetting, and tcp ip networks, explaining concepts such as class c subnet, calculation of subnets and hosts, subnet masks, limitations of devices on a subnet, and the importance of tcp ip components like dns, default gateways, and dhcp.', 'chapters': [{'end': 3206.353, 'start': 3069.318, 'title': 'Understanding subnet masking', 'summary': 'Explains subnet masking, highlighting the concept of a class c subnet, the identification of network and device portions in an ip address, and the use of bits to determine network and device numbers.', 'duration': 137.035, 'highlights': ['The chapter explains the concept of a Class C subnet, identifying the network portion of the address as 192.168.1 and the device identifier as 1.', 'It highlights the use of bits to determine network and device numbers, illustrating how different combinations of ones and zeros result in distinct IP addresses.', 'The chapter emphasizes the process of deciding network and host requirements, using the required number of bits to accomplish the task by dividing them accordingly.']}, {'end': 3968.408, 'start': 3206.353, 'title': 'Understanding subnetting and tcp ip', 'summary': 'Explores subnetting, explaining how to calculate the number of subnets and hosts, how to create subnet masks, and the importance of understanding tcp ip, highlighting the limitations of devices on a subnet and the necessity of routers for inter-subnet communication.', 'duration': 762.055, 'highlights': ['The importance of understanding TCP IP Understanding TCP IP is crucial, as it dictates the limitations of devices on a subnet and the necessity of routers for inter-subnet communication.', 'Calculation of the number of subnets and hosts Explains the calculation of the number of subnets and hosts using 2^n and 2^n-2, providing examples of subnetting and the standard number of hosts for different classes of subnets.', 'Creation of subnet masks Discusses the process of creating subnet masks, emphasizing the method of utilizing bits for subnet and computer identifiers, and provides examples of standard subnet masks for different classes.']}, {'end': 4168.932, 'start': 3968.428, 'title': 'Tcp ip networks overview', 'summary': 'Covered components of tcp ip networks including ip address, subnet mask, dns, default gateways, dhcp, nat, subnet masking, and cidr, emphasizing the importance of understanding these concepts for dealing with tcp ip and networking.', 'duration': 200.504, 'highlights': ['TCP IP components overview The chapter covered all the components of TCP IP networks including IP address, subnet mask, DNS, default gateways, DHCP, NAT, subnet masking, and CIDR.', 'Importance of understanding TCP IP concepts Emphasized the importance of understanding concepts like subnet masking and CIDR for dealing with TCP IP and networking, especially for those pursuing CCNA.', "DHCP lease renewal process Explained the DHCP lease renewal process where the computer tries to renew the lease at the 50% mark, and if it can't, it continues to attempt renewal at subsequent 50% intervals.", 'NAT function and significance Described the significance of NAT in allowing the reuse of IP addresses by internal networks, making it possible to use the same IP addresses within different internal networks.', 'Replacement of classful networks by CIDR Discussed the replacement of classful networks (A, B, C, D, and E) by CIDR, emphasizing the importance of knowing these concepts for dealing with TCP IP.']}], 'duration': 1099.614, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/EkNq4TrHP_U/pics/EkNq4TrHP_U3069318.jpg', 'highlights': ['The chapter covers subnet masking, subnetting, and TCP IP networks, explaining concepts such as class C subnet, calculation of subnets and hosts, subnet masks, limitations of devices on a subnet, and the importance of TCP IP components like DNS, default gateways, and DHCP.', 'The chapter emphasizes the process of deciding network and host requirements, using the required number of bits to accomplish the task by dividing them accordingly.', 'Understanding TCP IP is crucial, as it dictates the limitations of devices on a subnet and the necessity of routers for inter-subnet communication.', 'Explains the calculation of the number of subnets and hosts using 2^n and 2^n-2, providing examples of subnetting and the standard number of hosts for different classes of subnets.', 'The chapter covered all the components of TCP IP networks including IP address, subnet mask, DNS, default gateways, DHCP, NAT, subnet masking, and CIDR.', 'Emphasized the importance of understanding concepts like subnet masking and CIDR for dealing with TCP IP and networking, especially for those pursuing CCNA.', "Explained the DHCP lease renewal process where the computer tries to renew the lease at the 50% mark, and if it can't, it continues to attempt renewal at subsequent 50% intervals.", 'Described the significance of NAT in allowing the reuse of IP addresses by internal networks, making it possible to use the same IP addresses within different internal networks.', 'Discussed the replacement of classful networks (A, B, C, D, and E) by CIDR, emphasizing the importance of knowing these concepts for dealing with TCP IP.']}], 'highlights': ["TCP/IP version 4's dominance over other protocols like TCPIP, IPXSPX, and NetBUI.", 'Understanding TCP/IP version 4 is sufficient for the foreseeable future, with potential replacement by version 6 possibly by 2020 or 2030.', 'The composition of the TCP/IP protocol suite, emphasizing the main protocols and the structure of the protocol suite.', 'The role of the IP protocol in controlling the routing of information within the TCP/IP suite, specifying its function in directing data to various devices on the network.', 'The process of windowing in TCP involves how data is sent from one computer to another, highlighting its significance in facilitating communication between computers.', 'TCP windowing is crucial for data transmission between client and server, especially in scenarios of flaky communication lines, rooted in the military origins of TCP/IP.', 'The windowing process in TCP controls the communication between computers and ensures seamless data transfer, crucial for real-time communications and quality.', 'TCP/IP version 4 can be problematic for real-time communications due to the windowing process, impacting the quality of real-time communication streams.', 'DHCP ensures that every device on a network receives vital network configuration details, such as IP addresses, subnet masks, default gateways, and DNS servers, facilitating seamless communication and connectivity.', 'Network address translation (NAT) enables multiple devices to share a single unique IP address for internet communication.', 'The subnet mask (e.g., 255.255.255.0) determines the network identifier and device identifier within an IP address, critical for devices on different networks to communicate.', 'Routers are essential for connecting devices on different subnets or networks, even if they are physically connected to the same switch.', 'The chapter covers subnet masking, subnetting, and TCP/IP networks, explaining concepts such as class C subnet, calculation of subnets and hosts, subnet masks, limitations of devices on a subnet, and the importance of TCP/IP components like DNS, default gateways, and DHCP.', 'Understanding TCP/IP is crucial, as it dictates the limitations of devices on a subnet and the necessity of routers for inter-subnet communication.', 'Explains the calculation of the number of subnets and hosts using 2^n and 2^n-2, providing examples of subnetting and the standard number of hosts for different classes of subnets.', 'The chapter covered all the components of TCP/IP networks including IP address, subnet mask, DNS, default gateways, DHCP, NAT, subnet masking, and CIDR.']}