DHCP explained- DORA Process

hello everyone in this video I'm going to discuss about DHCP also known as dynamic host contribution protocol we all use mobile phones and laptops or PCs at home or at offices to access network resources such as Internet our printer etc to access the network and its resources every device on tcp/ip based network must have a unique unicast IP address along with the IP address each device must be assigned a default gateway an IP address of DNS servers following are the two basic IP address assignment methods static and dynamic static in this method an IP address is statically assigned to a device by the administrator the administrator configures the IP address subnet mask default gateway and DNS servers manually static address assignment method is an extra burden for the administrator especially on the large-scale network administrator must configure the address on every end systems in the network manually next is dynamic in this method IP addresses are assigned to the end system by DHCP server as I said earlier DHCP stands for dynamic host configuration protocol it is a client-server protocol used for address assignment with DHCP this entire process is automated and managed centrally this method relieves the administrator of manually assigning an address to every network device on the client machine you have to select the options as obtain IP address and DNS automatically it automatically provides all the parameters to the end device as you can see an IP address and other related configuration information such as subnet mask for gateway and DNS IP is assigned to the end device next we have DHCP School it is a pool of IP addresses or usually a range of consecutive numbers within a single IP subnet maintained by a DHCP server DHCP server assigns IP to the client from this pool or scope any numbers that the administrator does not want to have handed out can be excluded from the pool PACP adopts a concept of Lee's in IP allocation it sets a lease duration and allow the client to use the allocated IP address only during the set lease duration if the Clym want to renew or wishes to use the allocated IP address for longer than the released leased duration it should request the DHCP server for the renewal of the lease if the device is disconnected or powered off it releases the IP instead and returns to the pool for reallocation now let's take a look at exactly what happens when DHCP client requests an IP address from DHCP server there are some messages which are exchanged between the DHCP server and client these process is divided into four steps first step when a DHCP client first boots up it broadcasts a DHCP discovered message this message is initiated from the client to the server to find the DHCP server on the local network if the DHCP server exists on the local segment it will respond with the DHCP offer message this message is from the DHCP server to the DHCP client to offer the IT parameters once the client receives the offer it will respond with a DHCP request which indicates that it will accept the offered protocol information this message is from DHCP client to DHCP server giving a request to the get the offered IP parameters the final message the server responds with a DHCP ACK acknowledging the client acceptance of offered protocol information this message is from a CP server to the DHCP client confirmation to use the offer IP parameters this entire process is also known as Dora process DHCP is a UDP service uses two UDP port numbers for its operation DHCP server uses the EDB port 67 an dhcp client uses the UDP port 68 use of the port numbers prevent an application from getting a message from a completely different protocol what if the client and server are on different subnets well DHCP relay or DHCP helper agent must be used in this case other than dynamically assigning IP address to client machines DHCP also has the ability to provide various other interesting parameters or DHCP options to client machines like time zone information boot argument paths NTP server static routes interface MTU options host name of the client very useful for IOT and any device without user for more information on DHCP options please go to RFC one 533 that's it for today thank you for watching please like and subscribe and hit the ring bell button thank you

Channel: NETWORKING WITH H

Views: 9,529

Rating: 4.9322033 out of 5

Keywords: DHCP, networking, networkingwithh, video scribe, sprakol, training, sharing

Id: kS42C3vqFco

Length: 5min 50sec (350 seconds)

Published: Sat May 30 2020