title
Introduction to DHCP

description
Info Level: Beginner Presenter: Eli the Computer Guy Date Created: March 11, 2013 Length of Class: 21:35 Tracks Servers Networking Prerequisites Basic understanding of TCP /IP TCP/IP and Subnet Masking Purpose of Class This class teaches students what DCHP is and the core concepts of Dynamic Host Control Protocol. Class Notes DHCP stands for Dynamic Host Configuration Protocol DHCP is a Server Service Separate from DNS Can be found in Windows Servers/ Linux/ Unix and Home or Small office Routers DHCP Servers Assign: Dynamic IP Addresses Static Subnet Mask Static Default gateway Static Primary and Secondary DNS Servers Scope is the pool of addresses that the DHCP server can assign from. Such as192.168.1.100 to 192.168.1.200 Lease is the length of time that the DHCP server will reserve the IP address for the client. Clients will try to renew the lease periodically Lease length can be manually configured on a per server basis Reservations are IP Addresses that are reserved for systems that need Static IP Addresses Steps for Getting an IP DHCPDiscover -- Client Requests an IP from Any Available DHCP Server DHCPOffer -- DHCP Servers offer IP Addresses DHCPRequest -- Client Acknowledges which IP Address it has accepted DHCPAck -- DHCP Server Acknowledges Client has accepted IP Address Resources http://technet.microsoft.com/en-us/library/cc780760(v=ws.10).aspx

detail
{'title': 'Introduction to DHCP', 'heatmap': [], 'summary': 'Provides an in-depth introduction to dhcp, covering its dynamic ip address assignment for client computers and network devices, ip address configuration, lease renewal process, server and ip address management, and the leasing and communication scheme.', 'chapters': [{'end': 55.308, 'segs': [{'end': 55.308, 'src': 'embed', 'start': 4.107, 'weight': 0, 'content': [{'end': 4.768, 'text': 'hello again.', 'start': 4.107, 'duration': 0.661}, {'end': 10.232, 'text': "as you know, i'm eli, the computer guy, and today's class is introduction to dhcp.", 'start': 4.768, 'duration': 5.464}, {'end': 14.495, 'text': 'dhcp stands for dynamic host configuration protocol.', 'start': 10.232, 'duration': 4.263}, {'end': 21.08, 'text': 'this is the protocol that is used to dynamically assign ip addresses to client computers.', 'start': 14.495, 'duration': 6.585}, {'end': 32.65, 'text': "so if you, if you've done anything with tcp ip, you know that all computers, all devices on a TCP IP network require an IP address.", 'start': 21.08, 'duration': 11.57}, {'end': 36.132, 'text': 'now, way back in the horrible, really old days,', 'start': 32.65, 'duration': 3.482}, {'end': 42.878, 'text': 'you used to have to statically assign IP addresses to each and every device or computer on the network.', 'start': 36.132, 'duration': 6.746}, {'end': 48.782, 'text': 'you actually had to open up their little network configuration control panel and add the IP address manually there.', 'start': 42.878, 'duration': 5.904}, {'end': 50.484, 'text': 'that was a big pain in the butt.', 'start': 48.782, 'duration': 1.702}, {'end': 51.985, 'text': 'that was a big nightmare.', 'start': 50.484, 'duration': 1.501}, {'end': 55.308, 'text': 'so thankfully they came out with what is called DHCP.', 'start': 51.985, 'duration': 3.323}], 'summary': 'Introduction to dhcp, a protocol for dynamically assigning ip addresses, eliminating the need for manual configuration.', 'duration': 51.201, 'max_score': 4.107, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/g7mroO_BLD0/pics/g7mroO_BLD04107.jpg'}], 'start': 4.107, 'title': 'Introduction to dhcp', 'summary': 'Introduces dhcp, which dynamically assigns ip addresses to client computers on a tcp ip network, eliminating the need for manual assignment.', 'chapters': [{'end': 55.308, 'start': 4.107, 'title': 'Introduction to dhcp', 'summary': 'Introduces dhcp, which dynamically assigns ip addresses to client computers on a tcp ip network, eliminating the need for manual assignment, a relief from the old practice where ip addresses had to be manually assigned to each device on the network.', 'duration': 51.201, 'highlights': ['DHCP dynamically assigns IP addresses to client computers on a TCP IP network, eliminating the need for manual assignment.', 'In the past, devices or computers on the network had to have IP addresses statically assigned, resulting in a cumbersome and time-consuming process.', 'Introduction to DHCP by Eli, the computer guy, explaining its purpose and functionality.']}], 'duration': 51.201, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/g7mroO_BLD0/pics/g7mroO_BLD04107.jpg', 'highlights': ['DHCP dynamically assigns IP addresses to client computers on a TCP IP network, eliminating the need for manual assignment.', 'In the past, devices or computers on the network had to have IP addresses statically assigned, resulting in a cumbersome and time-consuming process.', 'Introduction to DHCP by Eli, the computer guy, explaining its purpose and functionality.']}, {'end': 189.092, 'segs': [{'end': 80.641, 'src': 'embed', 'start': 55.868, 'weight': 0, 'content': [{'end': 63.012, 'text': 'DHCP dynamically assigns IP addresses to client computers and network devices.', 'start': 55.868, 'duration': 7.144}, {'end': 68.395, 'text': 'So if you plug your computer into the network, or if you plug a network printer onto the network,', 'start': 63.072, 'duration': 5.323}, {'end': 77.699, 'text': 'or if you connect to a wireless network and you are automatically given an IP address, that is done through DHCP.', 'start': 68.395, 'duration': 9.304}, {'end': 80.641, 'text': 'So that is what we are going to be talking about today.', 'start': 77.959, 'duration': 2.682}], 'summary': 'Dhcp assigns ip addresses to devices for automatic network connectivity.', 'duration': 24.773, 'max_score': 55.868, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/g7mroO_BLD0/pics/g7mroO_BLD055868.jpg'}, {'end': 156.556, 'src': 'embed', 'start': 128.276, 'weight': 1, 'content': [{'end': 139.325, 'text': "So normally, when you're thinking about dynamically assigning IP addresses, you're also thinking about DNS, so resolving domain names to IP addresses.", 'start': 128.276, 'duration': 11.049}, {'end': 145.129, 'text': 'Well, DNS, domain name services, is a separate service.', 'start': 139.665, 'duration': 5.464}, {'end': 151.293, 'text': 'So a lot of times DHCP and DNS can talk to each other, But they are entirely different services.', 'start': 145.169, 'duration': 6.124}, {'end': 154.695, 'text': 'They can be installed on entirely different servers.', 'start': 151.593, 'duration': 3.102}, {'end': 156.556, 'text': 'And so they are separate things.', 'start': 154.995, 'duration': 1.561}], 'summary': 'Dhcp and dns are distinct services for ip address assignment and domain name resolution, often installed on different servers.', 'duration': 28.28, 'max_score': 128.276, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/g7mroO_BLD0/pics/g7mroO_BLD0128276.jpg'}], 'start': 55.868, 'title': 'Dhcp server service', 'summary': 'Explains the dhcp server service, focusing on dynamic ip address assignment for client computers and network devices, emphasizing its distinction from dns services.', 'chapters': [{'end': 189.092, 'start': 55.868, 'title': 'Understanding dhcp server service', 'summary': 'Explains that dhcp dynamically assigns ip addresses to client computers and network devices, emphasizing that it is a server service and only handles ip address assignment, separate from dns services.', 'duration': 133.224, 'highlights': ['DHCP is a server service that dynamically assigns IP addresses to client computers and network devices.', 'It is important to understand that DHCP only handles IP address assignment and does not deal with domain name services like DNS.', 'New technicians often mistakenly believe that DHCP also involves DNS services, but DHCP and DNS are entirely separate services that can be installed on different servers.']}], 'duration': 133.224, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/g7mroO_BLD0/pics/g7mroO_BLD055868.jpg', 'highlights': ['DHCP dynamically assigns IP addresses to client computers and network devices.', 'DHCP only handles IP address assignment and does not deal with domain name services like DNS.', 'DHCP and DNS are entirely separate services that can be installed on different servers.']}, {'end': 711.68, 'segs': [{'end': 234.641, 'src': 'embed', 'start': 189.413, 'weight': 3, 'content': [{'end': 194.096, 'text': 'So the first thing that it will provide is what is the IP address of the computer.', 'start': 189.413, 'duration': 4.683}, {'end': 196.918, 'text': 'So it will automatically assign the IP address.', 'start': 194.116, 'duration': 2.802}, {'end': 201.682, 'text': 'It will then also give it whatever the subnet mask it should be is.', 'start': 197.259, 'duration': 4.423}, {'end': 209.768, 'text': 'So the IP address may be 192.168.1.1 with a subnet mask of 255.255.255.0.', 'start': 201.842, 'duration': 7.926}, {'end': 213.59, 'text': 'Then it will also give the default gateway.', 'start': 209.768, 'duration': 3.822}, {'end': 223.095, 'text': 'So the default gateway is the router or modem that allows the computer to basically talk outside of the local area network.', 'start': 213.83, 'duration': 9.265}, {'end': 230.259, 'text': 'So to connect to the internet, connect to the WAN, the default gateway is the router that gets the computer off of the local network.', 'start': 223.115, 'duration': 7.144}, {'end': 234.641, 'text': 'Then you have the primary DNS server and the secondary DNS server.', 'start': 230.659, 'duration': 3.982}], 'summary': 'Automatically assigns ip address, subnet mask, default gateway, primary and secondary dns servers.', 'duration': 45.228, 'max_score': 189.413, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/g7mroO_BLD0/pics/g7mroO_BLD0189413.jpg'}, {'end': 386.622, 'src': 'embed', 'start': 356.096, 'weight': 0, 'content': [{'end': 362.081, 'text': 'So for the rest of this, let me go to my new little digital whiteboard so we can explain a few things here.', 'start': 356.096, 'duration': 5.985}, {'end': 371.707, 'text': 'So as I talked about, well I just said that the IP address is given dynamically, everything else is static.', 'start': 363.241, 'duration': 8.466}, {'end': 378.618, 'text': 'Well the IP addresses that are given dynamically are given from something called a scope.', 'start': 371.847, 'duration': 6.771}, {'end': 386.622, 'text': 'So the scope is the range of IP addresses that the DHCP server is allowed to give out.', 'start': 379.558, 'duration': 7.064}], 'summary': 'Explaining dhcp: ip address is dynamic, scope determines range of addresses to give out.', 'duration': 30.526, 'max_score': 356.096, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/g7mroO_BLD0/pics/g7mroO_BLD0356096.jpg'}, {'end': 466.146, 'src': 'embed', 'start': 430.013, 'weight': 2, 'content': [{'end': 433.676, 'text': 'it would not be able to give out an IP address such as 192.168.1.201, because that is not within the scope of.', 'start': 430.013, 'duration': 3.663}, {'end': 450.029, 'text': "So the first thing whenever you're dealing with these DHCP servers,", 'start': 444.725, 'duration': 5.304}, {'end': 458.955, 'text': 'is to realize the scope is the range of IP addresses that the DHCP server is allowed to give out.', 'start': 450.029, 'duration': 8.926}, {'end': 466.146, 'text': "Now you can normally what I do when I'm dealing with a DHCP server.", 'start': 460.219, 'duration': 5.927}], 'summary': 'Dhcp server assigns ip addresses within a specified range, e.g. 192.168.1.201 is out of scope.', 'duration': 36.133, 'max_score': 430.013, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/g7mroO_BLD0/pics/g7mroO_BLD0430013.jpg'}, {'end': 647.102, 'src': 'embed', 'start': 617.195, 'weight': 1, 'content': [{'end': 620.998, 'text': 'Well, how this can be dealt with is by something called the lease.', 'start': 617.195, 'duration': 3.803}, {'end': 632.729, 'text': 'So whenever a DHCP server gives out a dynamic IP address, it leases that IP address to the client.', 'start': 621.778, 'duration': 10.951}, {'end': 639.877, 'text': "So it doesn't necessarily give the IP address to the client, it leases the IP address to the client.", 'start': 632.81, 'duration': 7.067}, {'end': 645.1, 'text': 'Now, you can set up within the DHCP server how long you want leases to last.', 'start': 640.217, 'duration': 4.883}, {'end': 647.102, 'text': 'Do you want them to last one day??', 'start': 645.36, 'duration': 1.742}], 'summary': 'Dhcp servers lease dynamic ip addresses, allowing control over lease duration.', 'duration': 29.907, 'max_score': 617.195, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/g7mroO_BLD0/pics/g7mroO_BLD0617195.jpg'}], 'start': 189.413, 'title': 'Ip address configuration, dhcp, and dns', 'summary': 'Covers automatic ip address assignment, subnet mask, default gateway, and dns servers, with an example of 192.168.1.1 and subnet mask 255.255.255.0. it also explains the functions of dhcp and dns servers, including dynamic allocation of ip addresses, static configurations, and management of scope, reservations, and lease time in dhcp servers.', 'chapters': [{'end': 234.641, 'start': 189.413, 'title': 'Ip address configuration and network components', 'summary': 'Explains the automatic assignment of ip address, subnet mask, default gateway, and dns servers, with an example of ip address 192.168.1.1 and subnet mask 255.255.255.0, along with the role of default gateway in connecting to the internet.', 'duration': 45.228, 'highlights': ['Explanation of automatic assignment of IP address, subnet mask, default gateway, and DNS servers It will automatically assign the IP address, subnet mask, default gateway, and DNS servers.', 'Example of IP address 192.168.1.1 and subnet mask 255.255.255.0 The IP address may be 192.168.1.1 with a subnet mask of 255.255.255.0.', 'Role of default gateway in connecting to the internet The default gateway is the router that allows the computer to connect to the internet and WAN.']}, {'end': 711.68, 'start': 234.941, 'title': 'Understanding dhcp and dns servers', 'summary': 'Explains the functions of dhcp and dns servers, highlighting the dynamic allocation of ip addresses, static configurations for subnet mask and default gateway, and the management of scope, reservations, and lease time in dhcp servers.', 'duration': 476.739, 'highlights': ['The DHCP server dynamically allocates IP addresses, while subnet mask and default gateway are configured as static. The DHCP server dynamically allocates IP addresses from the defined scope, while the subnet mask and default gateway are configured as static, posing a risk of network communication disruption if misconfigured.', 'The scope of a DHCP server determines the range of IP addresses it can allocate, allowing for the creation of reservations for specific devices. The scope of a DHCP server defines the range of IP addresses it can allocate, enabling the creation of reservations to ensure that specific devices receive consistent IP addresses within the defined range.', 'Lease time in DHCP servers can be set to control the duration for which dynamic IP addresses are reserved, preventing address exhaustion in scenarios like internet cafes or enterprise environments. Lease time in DHCP servers can be configured to control the duration for which dynamic IP addresses are reserved, addressing scenarios like internet cafes or enterprise environments to prevent address exhaustion.']}], 'duration': 522.267, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/g7mroO_BLD0/pics/g7mroO_BLD0189413.jpg', 'highlights': ['The DHCP server dynamically allocates IP addresses, while subnet mask and default gateway are configured as static. The DHCP server dynamically allocates IP addresses from the defined scope, while the subnet mask and default gateway are configured as static, posing a risk of network communication disruption if misconfigured.', 'Lease time in DHCP servers can be set to control the duration for which dynamic IP addresses are reserved, preventing address exhaustion in scenarios like internet cafes or enterprise environments. Lease time in DHCP servers can be configured to control the duration for which dynamic IP addresses are reserved, addressing scenarios like internet cafes or enterprise environments to prevent address exhaustion.', 'The scope of a DHCP server determines the range of IP addresses it can allocate, allowing for the creation of reservations for specific devices. The scope of a DHCP server defines the range of IP addresses it can allocate, enabling the creation of reservations to ensure that specific devices receive consistent IP addresses within the defined range.', 'Explanation of automatic assignment of IP address, subnet mask, default gateway, and DNS servers It will automatically assign the IP address, subnet mask, default gateway, and DNS servers.', 'Role of default gateway in connecting to the internet The default gateway is the router that allows the computer to connect to the internet and WAN.', 'Example of IP address 192.168.1.1 and subnet mask 255.255.255.0 The IP address may be 192.168.1.1 with a subnet mask of 255.255.255.0.']}, {'end': 827.735, 'segs': [{'end': 755.947, 'src': 'embed', 'start': 733.074, 'weight': 0, 'content': [{'end': 742.059, 'text': 'so the lease is how long the client is given the ip address before it is given back into the pool.', 'start': 733.074, 'duration': 8.985}, {'end': 750.905, 'text': "now what happens is the the client computer will try to automatically renew the lease as long as they're on the network.", 'start': 742.059, 'duration': 8.846}, {'end': 755.947, 'text': 'generally this happens somewhere around the 50 mark on the lease.', 'start': 750.905, 'duration': 5.042}], 'summary': 'Ip address lease lasts around 50 units, renews automatically.', 'duration': 22.873, 'max_score': 733.074, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/g7mroO_BLD0/pics/g7mroO_BLD0733074.jpg'}, {'end': 836.998, 'src': 'embed', 'start': 811.268, 'weight': 1, 'content': [{'end': 820.853, 'text': 'it will still keep that IP address and then it will wait another prescribed amount of time to try to re-contact the DHCP server and see if it can renew it then.', 'start': 811.268, 'duration': 9.585}, {'end': 827.735, 'text': 'Depending on how the configurations are set up, the client computer may do this twice, three, four times.', 'start': 821.253, 'duration': 6.482}, {'end': 836.998, 'text': 'At a certain point, if it cannot contact the DHCP server, it will release its IP address and then it will go back to not having an IP address at all.', 'start': 828.095, 'duration': 8.903}], 'summary': 'Client computer retries contacting dhcp server multiple times before releasing ip address', 'duration': 25.73, 'max_score': 811.268, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/g7mroO_BLD0/pics/g7mroO_BLD0811268.jpg'}], 'start': 711.68, 'title': 'Dhcp lease renewal process', 'summary': 'Explains the process of dhcp lease renewal, detailing how the client computer attempts to automatically renew the lease around the 50% mark, and if it fails to connect to the dhcp server, it will make multiple attempts based on the configured settings.', 'chapters': [{'end': 827.735, 'start': 711.68, 'title': 'Dhcp lease renewal process', 'summary': 'Explains the process of dhcp lease renewal, where the client computer tries to automatically renew the lease around the 50% mark, and if it fails to connect to the dhcp server, it will attempt multiple times based on the configured settings.', 'duration': 116.055, 'highlights': ["The client computer will try to automatically renew the lease as long as they're on the network, usually happening around the 50% mark on the lease.", 'If the client computer cannot connect to the DHCP server when it tries to renew the lease, it will attempt to renew the lease again after a certain period of time, potentially trying multiple times based on the configurations.', 'The lease is how long the client is given the IP address before it is given back into the pool, and the DHCP client will contact the DHCP server to renew the IP address around the 50% mark on the lease.']}], 'duration': 116.055, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/g7mroO_BLD0/pics/g7mroO_BLD0711680.jpg', 'highlights': ['The client computer will try to automatically renew the lease around the 50% mark on the lease.', 'If the client computer cannot connect to the DHCP server when it tries to renew the lease, it will attempt to renew the lease again after a certain period of time, potentially trying multiple times based on the configurations.', 'The lease is how long the client is given the IP address before it is given back into the pool, and the DHCP client will contact the DHCP server to renew the IP address around the 50% mark on the lease.']}, {'end': 928.573, 'segs': [{'end': 858.997, 'src': 'embed', 'start': 828.095, 'weight': 1, 'content': [{'end': 836.998, 'text': 'At a certain point, if it cannot contact the DHCP server, it will release its IP address and then it will go back to not having an IP address at all.', 'start': 828.095, 'duration': 8.903}, {'end': 839.919, 'text': 'So that is what the lease is.', 'start': 837.378, 'duration': 2.541}, {'end': 846.048, 'text': "So at this point, so we've talked about the scope.", 'start': 843.226, 'duration': 2.822}, {'end': 854.514, 'text': 'So the scope is the total pool of IP addresses that the DHCP server is able to give out.', 'start': 846.228, 'duration': 8.286}, {'end': 858.997, 'text': 'Like I said, 192.168.100 to 192.168.1.200.', 'start': 854.674, 'duration': 4.323}], 'summary': 'Dhcp server leases ip addresses within a scope of 192.168.100 to 192.168.1.200.', 'duration': 30.902, 'max_score': 828.095, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/g7mroO_BLD0/pics/g7mroO_BLD0828095.jpg'}, {'end': 928.573, 'src': 'embed', 'start': 879.952, 'weight': 0, 'content': [{'end': 890.82, 'text': 'so reservations are if you have servers or computers on the network that need static IP addresses, you can actually plug that into many DHCP servers.', 'start': 879.952, 'duration': 10.868}, {'end': 899.987, 'text': 'so you create the scope whatever it is, and then within the scope you say 192.168.1.200 needs to be the small business server.', 'start': 890.82, 'duration': 9.167}, {'end': 901.608, 'text': "That's what the reservation is.", 'start': 900.307, 'duration': 1.301}, {'end': 906.512, 'text': 'Normally what I do is I create the scope, you know, .1.100 to .1.200 and then I make the server be 192.168.1.2 or 192.168.1.3.', 'start': 901.708, 'duration': 4.804}, {'end': 912.137, 'text': 'So normally I just create all the static IP addresses in a nice little cluster, usually at the beginning of the network,', 'start': 906.512, 'duration': 5.625}, {'end': 928.573, 'text': "the subnet that we're dealing with, And then I create the scope further down so that there's no conflict there.", 'start': 912.137, 'duration': 16.436}], 'summary': 'Create dhcp reservations for servers, avoiding conflicts with dynamic ips.', 'duration': 48.621, 'max_score': 879.952, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/g7mroO_BLD0/pics/g7mroO_BLD0879952.jpg'}], 'start': 828.095, 'title': 'Dhcp server and ip address management', 'summary': 'Discusses dhcp lease, scope, and reservations, highlighting the flexibility in defining the total pool of ip addresses and allocating static addresses for specific servers or computers within the network.', 'chapters': [{'end': 928.573, 'start': 828.095, 'title': 'Dhcp server and ip address management', 'summary': 'Discusses the concept of dhcp lease, scope, and reservations, emphasizing the flexibility in defining the total pool of ip addresses and the option to allocate static addresses for specific servers or computers within the network.', 'duration': 100.478, 'highlights': ['The scope of the DHCP server can be configured to allocate a pool of IP addresses, ranging from a small scope of 10 IP addresses to a larger scope of a thousand IP addresses.', 'Reservations in DHCP servers allow specific servers or computers to be assigned static IP addresses within the defined scope, ensuring consistency and ease of management.', 'Creating static IP addresses in a cluster at the beginning of the subnet and defining the scope further down helps avoid conflicts within the network.']}], 'duration': 100.478, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/g7mroO_BLD0/pics/g7mroO_BLD0828095.jpg', 'highlights': ['Reservations in DHCP servers allow specific servers or computers to be assigned static IP addresses within the defined scope, ensuring consistency and ease of management.', 'The scope of the DHCP server can be configured to allocate a pool of IP addresses, ranging from a small scope of 10 IP addresses to a larger scope of a thousand IP addresses.', 'Creating static IP addresses in a cluster at the beginning of the subnet and defining the scope further down helps avoid conflicts within the network.']}, {'end': 1290.506, 'segs': [{'end': 981.998, 'src': 'embed', 'start': 929.034, 'weight': 0, 'content': [{'end': 932.679, 'text': 'The big thing, though, to remember is this whole leasing scheme.', 'start': 929.034, 'duration': 3.645}, {'end': 938.555, 'text': "So the big problem with DHCP servers is you don't want them to run out of IP addresses.", 'start': 933.092, 'duration': 5.463}, {'end': 952.484, 'text': 'If the DHCP server only has a pool of 100 IP addresses and it gives out all those 100 IP addresses and then the 101st client computer tries to connect and get an IP address,', 'start': 939.516, 'duration': 12.968}, {'end': 956.906, 'text': "well then there's no IP addresses for that DHCP server to give out.", 'start': 952.484, 'duration': 4.422}, {'end': 964.771, 'text': 'So one of the ways that you try to make sure that you have enough IP addresses is through this leasing scheme.', 'start': 957.267, 'duration': 7.504}, {'end': 970.993, 'text': 'So the DHCP server leases an IP address to a client computer for a certain amount of time.', 'start': 964.991, 'duration': 6.002}, {'end': 975.695, 'text': "You plug it in, either it's one day or 100 days or five days, whatever it is.", 'start': 971.073, 'duration': 4.622}, {'end': 981.998, 'text': 'then, while the client computer is connected to the network at a certain set interval,', 'start': 975.695, 'duration': 6.303}], 'summary': 'Dhcp servers use leasing scheme to manage ip addresses, avoiding scarcity and ensuring connectivity.', 'duration': 52.964, 'max_score': 929.034, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/g7mroO_BLD0/pics/g7mroO_BLD0929034.jpg'}, {'end': 1098.1, 'src': 'embed', 'start': 1071.347, 'weight': 3, 'content': [{'end': 1077.03, 'text': 'And then the DHCP server sends back an acknowledgement saying that everything is A-OK.', 'start': 1071.347, 'duration': 5.683}, {'end': 1080.472, 'text': 'So this is how the communication goes.', 'start': 1077.39, 'duration': 3.082}, {'end': 1089.917, 'text': 'The client computer sends out a discover, then an offer is given, then the request is given back, and then there is an acknowledgement.', 'start': 1080.512, 'duration': 9.405}, {'end': 1098.1, 'text': "Now, If you've seen something here, if you've seen a security hole, you get an extra brownie point.", 'start': 1090.298, 'duration': 7.802}], 'summary': 'Dhcp server communication involves discover, offer, request, and acknowledgement. security concerns may earn extra points.', 'duration': 26.753, 'max_score': 1071.347, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/g7mroO_BLD0/pics/g7mroO_BLD01071347.jpg'}, {'end': 1148.369, 'src': 'embed', 'start': 1127.075, 'weight': 4, 'content': [{'end': 1137.003, 'text': 'basically the client computer will take the DHCP information given by whatever DHCP server gave it the information first.', 'start': 1127.075, 'duration': 9.928}, {'end': 1142.127, 'text': 'So this is something that you have to worry about with hacking and security, so on and so forth.', 'start': 1137.323, 'duration': 4.804}, {'end': 1148.369, 'text': 'is you want to make sure that any DHCP servers on the network are in fact yours?', 'start': 1142.127, 'duration': 6.242}], 'summary': 'Client computers take dhcp info from the first server, posing security risk; important to ensure network dhcp servers are legitimate.', 'duration': 21.294, 'max_score': 1127.075, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/g7mroO_BLD0/pics/g7mroO_BLD01127075.jpg'}, {'end': 1205.07, 'src': 'embed', 'start': 1173.291, 'weight': 6, 'content': [{'end': 1180.278, 'text': 'So this is a basic overview of how DHCP, Dynamic Host Configuration Protocol, works.', 'start': 1173.291, 'duration': 6.987}, {'end': 1185.703, 'text': "It's a pretty simple protocol, at least from the administrative standpoint.", 'start': 1180.338, 'duration': 5.365}, {'end': 1187.084, 'text': "There's not a lot to this.", 'start': 1185.963, 'duration': 1.121}, {'end': 1192.75, 'text': 'Again, this is built into everything, including these little routers or ISP modems.', 'start': 1187.205, 'duration': 5.545}, {'end': 1205.07, 'text': "There can be a lot of complication to DHCP, but generally when you deal with it, it's going to be pretty simple.", 'start': 1198.646, 'duration': 6.424}], 'summary': 'Dhcp is a simple protocol built into everything, including routers and isp modems, making it a key component for network configuration.', 'duration': 31.779, 'max_score': 1173.291, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/g7mroO_BLD0/pics/g7mroO_BLD01173291.jpg'}, {'end': 1254.744, 'src': 'embed', 'start': 1226.204, 'weight': 7, 'content': [{'end': 1228.446, 'text': 'You can create multiple DHCP servers.', 'start': 1226.204, 'duration': 2.242}, {'end': 1230.747, 'text': 'You can create things called super scopes.', 'start': 1228.726, 'duration': 2.021}, {'end': 1232.587, 'text': 'It can get really complicated.', 'start': 1231.127, 'duration': 1.46}, {'end': 1240.45, 'text': "But basically, what I showed you today is the general concept of DHCP so you understand what's going on.", 'start': 1232.888, 'duration': 7.562}, {'end': 1243.311, 'text': "So you've got the scope, which is the pool of the IP addresses.", 'start': 1240.47, 'duration': 2.841}, {'end': 1249.497, 'text': "You've got reservations that state Certain computers should have certain IP addresses.", 'start': 1243.551, 'duration': 5.946}, {'end': 1250.839, 'text': 'You have the lease.', 'start': 1249.797, 'duration': 1.042}, {'end': 1254.744, 'text': 'The lease is the length of time that the IP address is given out.', 'start': 1251.119, 'duration': 3.625}], 'summary': 'Dhcp allows creating multiple servers, super scopes, and managing ip addresses, leases, and reservations.', 'duration': 28.54, 'max_score': 1226.204, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/g7mroO_BLD0/pics/g7mroO_BLD01226204.jpg'}], 'start': 929.034, 'title': 'Dhcp leasing and communication', 'summary': 'Discusses dhcp leasing scheme to prevent ip address exhaustion by leasing addresses to client computers, and explains the basic communication process including dhcp discover, offer, request, and acknowledgment, highlighting security concerns and administrative aspects.', 'chapters': [{'end': 981.998, 'start': 929.034, 'title': 'Dhcp leasing scheme', 'summary': 'Discusses the dhcp leasing scheme to prevent the dhcp server from running out of ip addresses by leasing them to client computers for a certain amount of time to ensure availability, thus addressing the problem of ip address exhaustion.', 'duration': 52.964, 'highlights': ['The DHCP server leases an IP address to a client computer for a certain amount of time, ensuring availability and preventing IP address exhaustion.', 'One of the ways to ensure enough IP addresses is through the leasing scheme, where the DHCP server leases an IP address to a client computer for a certain amount of time.', 'The problem with DHCP servers is the risk of running out of IP addresses, which can be mitigated by the leasing scheme.']}, {'end': 1290.506, 'start': 981.998, 'title': 'Understanding dhcp communication', 'summary': 'Explains the basic communication process of dhcp, including the steps of dhcp discover, offer, request, and acknowledgment, highlighting the potential security concerns and the administrative aspects of dhcp.', 'duration': 308.508, 'highlights': ['DHCP communication process The chapter details the sequential process of DHCP communication, including DHCP discover, offer, request, and acknowledgment.', 'Security concerns with DHCP It emphasizes the potential security vulnerabilities in DHCP, such as the risk of unauthorized DHCP servers providing incorrect network information.', 'Administrative simplicity of DHCP It highlights the administrative simplicity of DHCP, especially in basic implementations, such as in routers or ISP modems.', 'Advanced features of DHCP It briefly mentions advanced features of DHCP, including creating reservations, multiple DHCP servers, and super scopes on Windows 2012 servers.', 'Importance of network security in DHCP It underscores the significance of network security in DHCP to prevent unauthorized DHCP servers from causing network disruptions.']}], 'duration': 361.472, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/g7mroO_BLD0/pics/g7mroO_BLD0929034.jpg', 'highlights': ['The DHCP server leases an IP address to a client computer for a certain amount of time, ensuring availability and preventing IP address exhaustion.', 'The problem with DHCP servers is the risk of running out of IP addresses, which can be mitigated by the leasing scheme.', 'One of the ways to ensure enough IP addresses is through the leasing scheme, where the DHCP server leases an IP address to a client computer for a certain amount of time.', 'DHCP communication process The chapter details the sequential process of DHCP communication, including DHCP discover, offer, request, and acknowledgment.', 'Importance of network security in DHCP It underscores the significance of network security in DHCP to prevent unauthorized DHCP servers from causing network disruptions.', 'Security concerns with DHCP It emphasizes the potential security vulnerabilities in DHCP, such as the risk of unauthorized DHCP servers providing incorrect network information.', 'Administrative simplicity of DHCP It highlights the administrative simplicity of DHCP, especially in basic implementations, such as in routers or ISP modems.', 'Advanced features of DHCP It briefly mentions advanced features of DHCP, including creating reservations, multiple DHCP servers, and super scopes on Windows 2012 servers.']}], 'highlights': ['DHCP dynamically assigns IP addresses to client computers and network devices, eliminating the need for manual assignment.', 'The DHCP server dynamically allocates IP addresses, while subnet mask and default gateway are configured as static, posing a risk of network communication disruption if misconfigured.', 'Lease time in DHCP servers can be set to control the duration for which dynamic IP addresses are reserved, preventing address exhaustion in scenarios like internet cafes or enterprise environments.', 'Reservations in DHCP servers allow specific servers or computers to be assigned static IP addresses within the defined scope, ensuring consistency and ease of management.', 'The DHCP server leases an IP address to a client computer for a certain amount of time, ensuring availability and preventing IP address exhaustion.', 'DHCP communication process The chapter details the sequential process of DHCP communication, including DHCP discover, offer, request, and acknowledgment.']}