DHCP Explained – Dynamic Host Configuration Protocol

DHCP Explained – Dynamic Host Configuration Protocol

hello everyone in this video we’re going to talk about DHCP or dynamic host configuration protocol now every computer or device on a network has to have an IP address for communication purposes an IP address is an identifier for a computer or device on a network and there are two ways that a computer can be assigned an IP address they could be done by using a static IP or a dynamic IP now a static IP is where a user assigns a computer or device with an IP address manually now this was the original method that was done in the beginning of networking so for each computer on a network you had to open up the computer’s network configuration page and manually type in an IP address but in addition to an IP address you also have to type in a subnet mask default gateway and a DNS server and anytime that you wanted to add another computer or device to the network you had to do the same thing so as you might have guessed this could be a lot of work especially if you are dealing with a large network that has a lot of computers and you also have to make sure that all the IP addresses are unique because if you assign the same IP address twice it would cause an IP conflict and would cause those computers to not have access to the network but there is a better and easier way to assign a computer an IP address and this is called a dynamic IP a dynamic IP is where a computer gets an IP address automatically from a DHCP server a dhcp server automatically assigns a computer with an IP address and in addition to an IP address it can also assign a subnet mask default gateway and a dns server so as an example here we have a network connection properties window open for the network interface card on a Microsoft Windows computer and as you can see here this computer is set to obtain an IP address automatically so when you choose this option the computer would broadcast a request for an IP address on the network then the DHCP server will assign an IP address from its pool and deliver it to the computer and then once that’s done you can verify all the different settings that the DHCP server has given your computer and you can do this by opening up a command prompt on a Windows computer and then type in ipconfig space forward slash all and then press Enter so as you can see here the DHCP is enabled on this computer which means that it’s getting its IP address from a DHCP server and then you can see the IP address here along with the subnet mask default gateway and DNS server so all of these settings were given by the DHCP server so as you can tell dynamic IP addressing is the best choice because it’s automatic and it makes managing a network a lot easier now a DHCP server assigns IP addresses to computers on a network from its scope and a scope is a range of IP addresses that a DHCP server can hand out so as an example here we see a scope of IP addresses on this server so as you can see the range starts with this IP address and ends with this IP address so computers on this network will get an IP address from this range of IP addresses so this scope can give out 100 IP addresses now these values can be customized to either increasing or decreasing the range it all depends on what the network administrator wants to do so it is customizable now when computers obtain an IP address from a DHCP server the server assigns the IP address as a lease so the computer doesn’t actually own the IP address it’s actually a lease and a lease is the amount of time an IP address is assigned to a computer for example the lease could be for one day now the reason for the lease is to help make sure that the DHCP server does not run out of IP addresses in its scope so as a demonstration let’s just say that this DHCP scope only has a range of three I pee addresses so it can only give out three IP addresses now obviously this is not very realistic because no network administrator is going to create a scope this small but for this demonstration let’s just use this as an example so let’s go ahead and add three computers to this network and as they are added the DHCP server is going to assign them an IP address so in this example let’s just say that the IP addresses are actually given to the computers and are not least so the DHCP has reached its limit on giving out IP addresses all of its IP addresses are currently being used but what happens if one of these computers is removed from the network so if a computer is removed it takes the IP address that it has been given with it so let’s say another computer gets added to the network but the problem is the computer won’t be able to access the network because the DHCP server has run out of IP addresses so even though this computer here has been removed it’s still occupying an IP address that could be used for another computer so this is why IP addresses are leased and are not given because if the IP addresses are leased then this will tell the DHCP server which IP addresses are still being used and which ones are not being used so in this example the IP addresses are leased so after a certain period of time during the lease the computers will send a signal to the DHCP server asking a server to renew its lease of the IP address so in other words it’s informing the DHCP server that it’s still present on the network and its IP address is still being used so if a computer is removed from the network that computer is not going to be able to ask the DHCP server for a renewal and if it doesn’t ask for a renewal then the lease will expire and then the IP address will go back to the IP address pool so now the IP address can be used for another computer and this is why IP addresses are leased now if you wanted a computer or device on your network to have a specific IP address all the time in other words you never want that IP address to change or you can create a reservation on the DHCP server a reservation ensures that a specific computer or device identified by its MAC address will always be given the same IP address when that computer or device requests an IP address from the DHCP server so for example on this DHCP server if I create a reservation for my computer the DHCP server will recognize my MAC address and will always give me this specific IP address now reservations are not typically given to regular computers they are typically given to special devices or computers such as Network printers servers routers etc because devices like these should be given the same IP address constantly now one final thing to note about DHCP is that DHCP is a service that runs on a server for example this could be a Microsoft server or a Linux server but it’s also a service that runs on many routers also whether the router is a business router or a small office/home office router these routers will have a DHCP service built into them you

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  1. You should make some course/tutorial, cuz this is worth to pay and interesting to learn. In a nutshell, you are a good teacher. Thank you!

  2. DHCP servers mostly don't give out as an ip adres, cuz this IP is mostly the gateways IP adres. It mostly starts with IP adres.

  3. So when we connect a laptop to the internet with a smartphones WiFi hotspot does this mean smartphone also have build in DHCP servers?

  4. If you are me ict teacher..I'll pass exam with top marks.
    Great explanation man..keep it up like this

  5. I request you to provide any links in description to notes or web links that you were studied because that would make you a extraordinary teacher.

  6. Nicely put, love the graphics love the approach. i automatically enabled ads on your channel to support you. Please keep videos coming I have an interview tomorrow and I have learned a lot from your videos THANK YOU! – SUBSCRIBED!

  7. Venkatesh from india.sir, your the best teaching ,, easy to learn and understand .. thank u so much..

  8. I have learnt so much with this explanation, I am fully appreciate mate and may GOD keep Blessing you in full and all of you who read this in JESUS'S name, AMEN

  9. 2019 0:45 > this was alot of HARD Work – ? like building a house or chopping 2 tons wood ? 😳haa u Nerd 🤪 The video are good learning just saying typing hard work>> u aint done hard work mate get dirty

  10. Great video! One question: in your homenetwork you may have a router, a switch and a NAS – each dice capable as serving as a dhcp server. Which one ro choose? To old router or the very modern managed highperf switch?

  11. Your videos are absolutely amazing. Im in my 2nd semester of networking and after watching 3 of your videos I know more than I learned in the 3 classes that I got A's i.

  12. Im an engineer and I tell you your channel is awesome !! just keep up the good work ..
    we need one video about VPNs.

  13. Everything is good but i think the DHCP process should be explained a bit more. (Discovery, Offer, Request and Ack).
    Nice job..

  14. My Prof spent almost 1 semester to teach these concepts but you can cover them up in less than 10 videos, Bravo !!

  15. Man, this channel is a god sent. Thank you, YouTube algorithms. Subbed right away and I'm going to watch every single video. I have needed this for a while. Thank you.

  16. So if i change my router dns settings and then use dhcp on my phone will my phone be using whatever dns i have set up on my router???

  17. The problem with DHCP arises when you have specific addresses assigned to computers, say for the puropses of scanning to each computer from a central multifunction scanner that maintains a list of computers that it sends scans to. In this case you either have to reserve every PC's IP address (problematic if you ever change the router) or simply assign static addresses.

  18. I didn't know the best tech channel on YouTube has been missed by the world

  19. normally in a LAN the dhcp server is the router, right?? in the internet the dhcp server is the provider of internet

  20. Thanks, I enjoyed the presentation, very well done. you got a like and subscribe from me.
    Would you be able to describe the how the communication between the computer looking for an IP address and the DHCP server works before the time the IPv4 address is assigned? That is, the broadcast from the requesting computer, listing for the broadcast by the DHCP server and ultimate assignment of the IP address. I'd also like to know how IP address requests are answered when there are multiple DHCP servers in the same broadcast domain. Thank you.

  21. Thanks for your work! Your lessons are incredibly useful and understandable.
    P.S. I'm student from Russia and my English is pre-intermediate.

  22. why wouldn't you want every computer to stay with the same ip?, isn't it easier? also why would you want to make an ip of a printer the same, it has mac adress anyway

  23. In my opinion, you are one of the best teachers out there – always hitting the core questions, accompanied by very helpful animations – many, many thanks.

  24. Now that's how you teach, making things as simple as possible for the student Great Job. What presentation software are you using? I need to create some technical training videos.

  25. 🙏🙏🙏🙏🙏🙏🙏Sir, I can`t thank you enough. Unimaginably simplified teaching of these concepts would make the life of a person like myself, who is just starting out in the world of Networking, easier than anyone can fathom. Much respect from the Subcontinent.

  26. Power cert animated ..u.r.amazing..i learned lot of topics in Networking ..this can be happen .only by saw..ur..videos…thank..uuu..Soo..much..🙏🙏🙏

  27. The best video about DHCP EVER. Simply, clear and easy. Thank you for uploading this vídeo, has been very helpful !!

  28. I Love your outro man! 😀 I hope this will never happen to me, but actually my antenna is higher than the lightning conductor 😀

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