DHCP: How Your PC Gets Its IP Address

[@slidenerd]

dude, bloody awesome! as Einstein says, you can simplify it if you understand it, that was totally badass

[@jibin7277]

Better than reading 1 whole text book !!!

[@BLBytes]

My Cisco course taught that the messages were: DHCP Discover - Broadcast DHCP Offer - Unicast DCHP Request - Broadcast DHCP ACK - Unicast The server can send unicast messages because it knows the MAC address of the client from the original discover frame sent out. Since DHCP will only really happen on a local network (with exceptions) it doesn't need to know the IP address of the client, only the MAC. The client broadcasts the request so that if there are other DHCP servers on the network, they can see the request too. Only the server that made the offer will ACK the request.

[@bekcekcingnaknyet1382]

tru dat, but then the grandmas don't need to know the whole cisco system, the video has done its job of stopping the regular questions of some grandmas with slippery fingers "why these numbers keep on changing?"

[@ApexSpeedster]

yes u r correct.

[@raydenross477]

That is true grandmas don't but networking students looking to study subject matter do. It seems as though we catch it anyway so I digress

[@slokaroy4430]

It is because of ARP(Address Resolution Protocol) Reverse-ARP in the cache provided by the server.

[@h-batchmailadmin5958]

Its the best video with excellent explanation i've known so far ! Thankyou sir !

[@paleshyrain]

more videos please. youre doing a great job! better and simpler explanation than the ones given by my professors in college.

[@ajaytamang5957]

Pieter you the best man when it comes to explaining the technical stuffs in simple language.

[@MrSaemichlaus]

These videos are a pleasure to watch! Superior design and clear words, very well done.

[@DaBBoSaH]

your style is really nice, please don't stop, keep it up

[@oranjizer]

One of the best, very well explained videos on the concept.

[@kirandevkumble6975]

dude u really make a great videos . Your teaching method is really awesome . Dude come on, make some more .Where are you?

[@Gg8YRwnc3e]

Professionally & beautifully done and explained. Thank you. 10/10 :)

[@wangyuntong9428]

So clean and simple!!!! I love your illustration ~ Helped me before exam

[@nishadkumar7322]

And the emmy award for making things simple to understand goes to YOU!! Great video!!!

[@Drew.DrivesYT]

Just remember DORA and you'll never get confused.

[@peachapple960]

Ozma2112 Man! You're a genius! You've just saved me for my exam! Thank you!

[@freeze30able]

ur better than any of my teacher. u explanation is so so good.

[@tonywang7933]

Thank you so much, to make it so simple and clean. Hard to find anything with this good quality. Don't know why there are down votes

[@andrewlira1537]

The down votes are those who were jealous of Peter's superb videos perhaps. They're in vain lol

[@DanielBuenrostroC]

You saved my life, Thanks!

[@konradlubaszka3769]

Another great entry describing the principle of operation of these complicated things. I really like your simple explanation that can be easily understood by people who are taking the first steps in networks. Did you could make a video in which you could explain the principle of DAS , NAS and SAN on some examples? This would help me a lot

[@sourabhsomdeve1373]

Bro how easily you explain this.....i definitely show this video to my teacher and tell him to explain in this way......

[@PotatoChixMoMo]

Mannnnn...u r better than my teacher. 100 times better than a teacher out there

[@UpusCumupus]

hi pieter ..just like to tell you that i really enjoy your videos. They're very informative and easy to understand! Keep up the good work.

[@TheMooseLP]

I might understoond it wrong but at 3:17 the broadcast sound not reach the second laptop, because the router stops it and divides the network in separate broadcast areas.

[@j7ndominica051]

The network should still used static addresses if possible, to make it organized, except these addreses can be managed from a central table of static leases on the router. It makes sense to give the "laptops" host numbers 1,2,3,4, give the "smart TV" address 17, and let guest "devices" share a pool .128/26 that doesn't overlap with these. Then you can easily put a server on any laptop, or write a firewall rule that restricts the devices as a group. What DHCP enables is to move those portable hosts onto a different network without reconfiguring them manually.

[@seetsamolapo5600]

-DHCP server typically inbuilt in a router and a DHCP client in built in each host - When a new host is added to a network it goes through a DHCP discover process, looking for a DHCP server. Since the host doesn't know where the server is it will send a discover request (broadcasting) to all devices on the local network. Port 68 - DHCP clients, port 67 - DHCP servers - The DHCP server then responds by sending a broadcast of an allocated/offered IP addresses to all hosts. Since the server doesn't know where to find this new host it sends the DHCP offer to everyone

[@jgwood89]

maaaaaaan come BACK!

[@bekcekcingnaknyet1382]

thanks Pieter you're a legend, my grandma really loved how she can finally got it without an argument with me :D

[@applegaming3461]

That was simply superb. May I request you to share similar tutorial on DNS to public?

[@SimplyWreckless]

I have completed the cisco small home and networking course , but I want to do an apprenticeship within networking , but most of the roles involve using windows server. Now I know that dhcp can be set on clients computers to enable them to obtain ip addresses. But say for example the dhcp server is a computer host using windows 2008 server does the ip address of this machine have to be static. And it is a larger business so they use more dhcp servers,

[@junaidtanoli1]

Pieter your videos are awesooooooomeeeeee

[@ayushmalik8317]

reply from DHCP server to client is dependent on the flag if it is set then broadcasting​ is done if reset then unicasting. in Cisco router it is reset by default so reply is generally unicast. Unicasting can be done by using the physical address of the client sent during the request for IP.

[@BoomWahDis]

Wow just frigging wow .why doesnt everybody explain it like that,the teacher?😢😢 .God bless you sir , thank you thank you .

[@hakeem4793]

Damn your explaining is so simple and easy to understand. I wonder why don't you upload no more

[@davidkimkan]

I enjoyed this explanation of how DHCP works. Very nice video.

[@Trotskisty]

A very clear exposition. Kudos.

[@meochieng]

Very informative video. Good work, Pieter!

[@Gazunklenut]

Sometimes the DHCP server will unicast the ACK message if the host is behind a switch using MAC addresses, the switch would then broadcast the message to all connected hosts.

[@razpet20]

Cmon Pieter, thousands of computer science students depend on you making more videos, for finishing their course! :D

[@wliaputs]

Should provide a summary at the end of the video. So here's the summary on how DHCP works: 1)DHCP Discover [ By Client ] (Search for DHCP server) 2)DHCP Offer [ By Server ] (Offering an IP to the requester) 3) DHCP Request [By Client] (Agree with the offer) 4)DHCP Ack [ By Server ] (Acknowledge the agreement, set the offered IP to the requester)

[@arunhit1993]

i liked this video it clearly explained the doubts i had with DHCP, i dont know what it is. very good presentation.

[@recolian]

man you earned 55K subscribers just by uploading 6 or 7 videos. why would you not keep doing this!

[@zealeatoire]

I love it. Thank you very much for the videos. 2 ideas maybe for additional videos. Access Control List, Routes Tables?

[@paterson00]

Thanks for creating the video. I need to know this stuff in the future for work as networks become more and more used. I work in the railway and equipment in the field is now communicating like this and I will be left behind if I don't start to learn it. I didn't get everything there but I am starting to understand. The illustrations help a lot

[@karthik20121]

Hi Peter, I would like to know the difference b/w 1. Dynamic allocation 2. Static allocation 3. automatic allocation.

[@thepoojaghosh]

I would like to see a video featuring transmission of packet in a network and how it operated with a swatch and router, also a video featuring transmission of packet through all the osi layers

[@nikhilnagaraj4113]

Best explanation on net bud.. Subscribed

[@youarewelcome2009]

Note: 0 0.0.0 stands for the zero network (local network that is not forwarded by routers). 255.255.255.255 allows all devices connected to the local network to accept UDP datagrams. Before packages become packages (network layer) they are called segments or datagrams. (Depending on which protocol is used on the transport layer, TCP or UDP) DHCP uses UDP as is it a stateless protocol and does not require a connection. Hope this helps.

[@wolfteamUpdates]

Please make some more videos. You are the best.

[@Wizardboz]

maybe its just because I'm ready for the info but this really easy to understand. THank you, im watching all your videos now lol

[@kikaider003]

Great instructional video please help. Im having an issue with my smart tv. The router connection went down for a few hrs, when it came back I could no longer access my smart tv features such as youtube or the browser. I checked the network on the tv and it says connected, a message also appears saying something about dhcp

[@VishalSharma-gt1hy]

what is the message ?

[@theot58]

Awesome videos - clear, consice and easy to watch.

[@ankitprajapati3768]

Just one word want to say. Excellent!!!

[@SOU6900]

This answers the big question I have with my network which is how the DHCP works on my wireless router since I know I don't have a DHCP server. I'm assuming that a router that is connected to a switch can be used as a DHCP server as well.

[@sriniatiisc]

Pieter. What a nice work you have done in simplifying the tutorial about DHCP. We need more videos like this. Great work.

[@MasEja]

hey,Im Reza from Indonesia. i need you to explain the routing protocols like OSPF,BGP,RIP and EGRP .Thanks for your attention .

[@linkedcvsite7431]

Hey Pieter, thank you so much for this video - it explains the concepts very well and helped me prepare for my upcoming exam! Is there any way to download the presentation slides you used here?

[@aragiewube8833]

wow your explanation is accurate and in understandable form!thanks sir...

[@Atpugtihsrah]

You're great in explaining things! The idea of how the datalink, network and transport layer execute in tandem is still fuzzy in my mind. How the frames, datagrams and messages(segment) are encapsulated in each other? Could you please explain this thing or refer me a good video like this?

[@victorklimov5254]

perfect explanation!

[@charchildudani6675]

Hello Peter.. I like this simple and clear explanation.. could you explain with the packet format ?

[@badavinaykumarreddy1199]

Great explanation. But i have two questions, 1)what would the source and destination mac addresses at layer 2 in the DORA process ? 2)why would the dhcp server sends broadcast offer and ack packets even though it knows the mac address of the client?

[@zhiyaowang8826]

Excellent videos! Wish you can make more. Like the HTTP request and what happens when we visit a website.

[@akhilvarghese206]

nice description is simplest way possible. :)

[@Learnwithspades]

peter that awsome... thank you.. did you know what is recursive and iterative query in dns ???....'

[@SimplyWreckless]

and another thing is i get confused with 'domain names' , do you create the domain names using the windows 2008 server host computer. also with 'network' The term the wireless router is considered when a computer connects to the wireless network , but LAN is the local area network , is that when the ethernet or cable from the switch is plugged into the modem ?

[@chrisvillareal7140]

Hi @PieterExplainsTech I watch all of your videos and all of them are very good and well explained. I wonder why you didn't continue to add more videos? I only saw few of them. I hope to watch more of your contents about computer networking. Thanks!

[@shivanisrivarshini180]

Sir your videos are simple and understandable thanks for your explanation Please make more videos . I want to know about application layer protocols and about stateful protocols in application layer Thank you

[@billyboller9871]

I would like to see you explain frame relay.

[@aakashgautam9805]

Awesome explanation . Could you please make a video tutorial for dhcp server configuration for a small network in linux based machine . Particularly in my scenario i have 10 laptops and i should complete a project on dhcp server for providing those machines unique ip address . If i use a router it have a built in dhcp server in it but i want to know how can i make one of my machine over my network as a dhcp server . Please guide !

[@EddieSundvall]

One thing I'd like to see is of course how data packets are routed through the internet, although I understand its a science field of its own.

[@_burd.]

I like how the superhero has a butt, but this is a lifesaver. The clearness of the explanation made me understand in an instant and the backstory of everything makes me more interested in the topic. Thanks!

[@marinakim2929]

Pieter come baaaack, i miss you!

[@h.oliabak]

I have a question: The client in the first step creates a discovery message for example by transaction ID = 655 and this will be broadcast. Suppose there are many DHCP severs in the network, they all will receive this message by transaction ID = 655, and they all in the second step offer an IP address with that transaction ID. So the client will receive many messages with the same transaction ID but maybe different offer, (am I right till here?). then in the 3rd step the client broadcasts the chosen IP address as a request message with transaction ID = 655, now here which server would send the Ack message?

[@kso35]

hello 2021----Wish you could upload more, Pieter. Your content is helpful. Thank you!

[@NikolayNechaev]

And what's about if there are multiple machines trying to connect to one DHCP server in one moment? If the DHCP server broadcasts a new IP address, multiple computers can send a DHCP request... By the way, is it possible that after a machine answers it doesn't want to use an IP address after the DHCP offer?

[@wacz016]

In step 3, why does the new computer on the network broadcast the DHPC request to all devices, when it knows the IP adress of the router from the offer it received in step 2?

[@deveshgautam6198]

Hi Peter, Step 2: Offer packet should be unicast because the server identifies the rest of the network node.... ? Please right if it is making sence to you...

[@ankitprajapati3768]

Plz upload video on why we need both ip and mac addresses. Thanks in advance.

[@rameshram6875]

when the dhcp server(192.168.1.1) offers new ip address 192.168.1.3 for new host then why new host bradcast the message "dhcp request" on the network without sending only to 192.168.1.1 address who is the dhcp server

[@manojg7144]

Hi Pieter, Love your channel... Please explain the differnce between MAC address and IP address.

[@spicyLEGO]

In step 3, why is the receiver IP address set 4x 255? The DHCP server have already sent an offer with its sender IP in step 2, right? Why can't the client send a accept signal to that specific IP address, instead of broadcasting it? Sorry if I asked too many questions.

[@vaishnaviandvihaan]

Good topic & you explained well. What is the diffrence between DHCP & DHCP option set in Amazon Web Services?

[@pupulmayank3823]

I am not sure if anyone still is responding here or not, but why is it that the Request and Ack steps are broadcast? Why can't the client make not of DHCP IP from Offer step and then send a unicast message to DHCP server only. I understand that DHCP server might still not have the IP address of client and that can still be a broadcast but the Request can be unicast. Isn't it? Also a continuation: When DHCP sends the offer message as a broadcast or Ack message as a broadcast, I know that other clients in the network discard that message. But how do they discard it? What is the parameter based on which they decide that it is of no use for them?

[@rpiian]

I was trying to connect a solar inverter w/dhcp to a switch which was then connected to a modem. The inverter could not pull an IP address from the switch so replaced the switch with a router and voila, the inverter could connect. Obviously this was the addition of a DHCP server. Is it impossible to get an IP address when I connect: Device > Switch > Cable Modem ?

[@B0nztube]

hi how to solve this issue? here's the scenario.. user used laptops, sometimes they can connect.. but there's another time that they didn't. "i have set.up here a dhcp server in clear os and the 2 wifi router is acting now a access point" users laptops is using dhcp but can't have IP address from dhcp server, only the autoconfiguration ipv4 will shown it give IP automatically but a wrong ip. what i do is: restarting the 2 wifi router and restarting the dchp server and i also using putty to restart the service by using this code "sudo service dnsmasq restart" but unsuccessful.

[@Alex-mv3ht]

If the offer UDP packet contains the router IP, why does the the host still broadcast the request instead of sending it directly to that IP?

[@tayadihyt]

Thank you very much. very clear to people who are new to IT/networking. what is your next project?

[@nilakshatra2024]

Totally awesome. I need a bit of a help. I need to hook up my laptop (running ubuntu) with a raspberry pi (running ubuntu, not raspbian) only with an Ethernet cable. I have a DHCP server running on my laptop, which means I only need to add a DHCP client on my Rpi and add it to startup application list, right? If there's a better way with given limitations (only ethernet cable), Can you please tell me?

[@praveenkumarsettipalli3963]

Hi peeter, I have few questions :- 1.How the system came to know about the DHCP is connected to my system ? 2.With the DHCP enabled if the conflict happens,so How the system can know about the conflict ? what's happening at the back end ?

[@adityapandya1572]

Thanks man......it was freaking awesome and so simple too....doing a great job

[@chiheangchea9460]

hi PieterExplainsTech, i need some suggestion from you i use tp-link router (model TD-w8960N) as main router.and i have 3 pro-link access point (model prn2001) using as repeater from main router(share by wirless, dont use any cable).after i configue pro_link do as repeater , it work simply(mobile phone can connect and access to the internet).but after few hours late , the repeater isnt working (mobile phone cant connect and access to the internet(the phone still obtaining ip address)).i dont know the DHCP problem or something..! one more thing, my DHCP provide ip address to connection device 24h,if phone_A connect to wifi 1h, then phone_A disconnect( stop using wifi).that ip can't use(need to waiting more 23h). i think it is waste my ip, but i dont know where to manage it, maybe my router dont have DHCP management function..!

[@Iamherp]

Hi peter, does one need to always use the private Ip address ranges on a private network? What happens if I assign a public address to my own private network instances and then use an internet router to connect my private network to the internet? Wont it still work? i.e. switch all 192.168. to something like 24.1

[@gainev6108]

Is the DHCP Server considering Static IP Adresses I haven given to hosts ? Will there be a conflict, if I have a configured a static IP adress on my laptop ?

[@stevepalmateer]

Why do you use the terms sender/receiver as opposed to source/destination?

[@abhishekbahuguna1130]

How can a router broadcast the offer and ACK . The use of router is to split the broadcast domain , otherwise what is the benefit of using a router. Just imagine the number of hosts being connected to the network and how much traffic they will generate , and so much unnecessary ACK and Offer will be broadcast to all hosts. It is like unnecessary traffic and will lead to congestion. Once the IP is assigned , hosts can use gratious ARP to validate if IP is unique or not

[@thomasxeon1912]

Thanks, can you explain about the DHCP option?

[@navekeinan]

about the transaction ID. how's that going in my house when I have 2 computers and A router ? does the routher give ID's to my computer ? how does he know by the mac address ?

[@VARDHAN_CAPTURES]

Sir your way of explanation is awesome. can u please confirm me is DHCP four steps process is same for wired and wireless networks ?

[@sandejai]

I haven't finished watching it, but I am compelled to , thank you :)

[@kalpeshss]

Good explanation Pieter. Superb. Easy to understand in common lay mans language with graphical representation. Do u have more vidoes on subnet mask, subnetting or VLSM etc ?

[@AdrianJuliusRandall]

When we say join the network does it stay the same after the first time it gets on the network, or is there a new ip address assigned everytime a computer hops on the internet or is it the first time you connect to a wifi password and router?