Free CCNA | IPv4 Header | Day 10 | CCNA 200-301 Complete Course

[@damirmuslimovic9650]

for anyone struggling in this part. this is what works for me: i write down everything from the video (hand writing and not over computer as i tend to remember more that way) after Jeremys video ends, i read through everything and compare the fields to a picture on the internet. additional use of anki cards is a game changer. Rewatching a video after a break is also helping. it is tough, but remember its a marathon and not a race. You got this! Jeremy, thank you for all the videos.

[@martisimeonov]

If it's hard, it means we are progressing! Keep it up fam

[@JeremysITLab]

Thank you :)

[@scottmcarthur7496]

good analogy

[@Bjon10]

Did you get your CCNA brother?

[@fatimahamdan3825]

when I get a job inshallah , I will send you on paypal .. you are the reason why I love network now thank u so much for the effort , please dont stop

[@JeremysITLab]

Thank you so much, I'm glad you love networking!

[@syedh2649]

Hi were you able to get job?

[@shubh_1836]

What I like about your method of explaining is the occasional use of comparisons and reference to past lessons. This helps me connect the entire course together in my head and also to develop a point of view and not only just remember facts. Thanks again!

[@JeremysITLab]

Thanks, glad to hear that :)

[@rohitrawat5581]

I have never seen content like this relating to CCNA or network fundaments. Seriously I appreciate you sir with all my heart.

[@gottabepablo]

For those having trouble understanding, just realize that the fields in the header all work together to get a few things done. Firstly, enable QoS via the DSCP field. Secondly, three fields are dedicated to the division of a packet into 'fragments' if it is too large. Fragmentation and reassembly is facilitated by the Identification, Flags and Fragment Offset fields. Lastly, and of course far from least..the Source and Destination fields provide inter-network routing. I left some fields off but the important thing to note is what important functions the fields provide. For rote memorization of field sizes and packet minimums and maximums, the flashcards really do help, so do them! It is free!

[@ghosttheripper8656]

This helped exponentially -- I try to break down the stuff usually but was tough for this one, thanks -- hopefully this helps it stick!

[@gottabepablo]

@ glad to hear!

[@АлексаМиловановић]

🤯 🤕 Too much information, other instructors will put me to sleep, but your videos keep me excited and motivated to learn. I can even watch your videos several times. :)

[@JeremysITLab]

Indeed there is a lot of information to remember! Glad my videos are helping you :)

[@jimmy2d756]

he is professional in this area

[@jakubpluhacek3779]

@Studio S.S Do not try to remember everything like this, write notes, I use dropbox paper and it really helps!

[@TyshawnGreen]

Facts

[@Manu-rd4pc]

Yes that's a lot of information!! The flashcards are really good but there are also too many of them! 56 just for this lesson is too much i think 🤕🥴

[@Wei-ji9ou]

Man... this part rough , thanks all the works you've done for us .

[@JOYCEWANJERI]

It is simply amazing how you make complicated content so simple. Thanks so much Jeremy.

[@JeremysITLab]

Thanks Joyce :)

[@SammyOmari254]

Hello my fello Kenyan🤝🤝

[@julkiplilanga538]

Time could not erase the nature of your teaching in sharing us knowledge... You become a part of my IT career... Thanks a lot GOD BLESS...

[@JeremysITLab]

Thanks for your comment, I'm happy to help :)

[@Reason_over_Dogma]

Man, this is a lot of information. I really have to attack the flash cards. I get the basic concept but its a lot of material to remember for a header. Thanks for the flashcards and the visuals. It will aid a lot in studying this material. I may have to watch it a few times and study this deck separate from my combined deck until I nail it.

[@cornilpatidar]

Did you pass the exam? Is it necessary for the exam?

[@JB-jn9kb]

@@cornilpatidar honestly, you probably won't see one question about this stuff on the test to include most of the stuff in the first 10 days worth of videos. If you were going for a lessor cisco exam like the CCST you would see this stuff, but the ccna expects you already know this stuff. It's a great foundation for what's to come. Unfortunately everyone wants to skip over the entry level certs and go to the much harder certs, which is why folks end up here. The same happens with Comptia certs. Everyone skips net+ and A+ and goes straight for Security+.

[@narutolol3199]

@@JB-jn9kb a + and net + is kinda useless for those already in college

[@tech5186]

this is the first video in this course that i didnt understand it well its very complicated for me :( i hope its not very important in the exam

[@JeremysITLab]

I recommend watching it again and trying to learn it. This is probably more detail than you need to know for the exam, but at least be familiar with the purpose of each section of the IPv4 header.

[@GursewakSingh-tj3xz]

true i agree too. it's a bit complicated i assume . but thanks jeremy keep posting. we will understand at one point

[@cipherion]

@@JeremysITLab Do you think it’s important to memorize cabling distances and ip header byte information?

[@sarahsarah9610]

I was about to post a comment ''is this video complicated for everyone or just me?'', and I saw your comment first :) so it seems that it is complicated for most of us.

[@Maplemischiefmaker]

Even I couldn’t understand this one , is there any way to understand it better

[@latenightcanvas147]

Your walk throughs are always so helpful. I had struggled to find any class that as in depth as I need but now i feel confident I can pass my CCNA!

[@marcinborkiewicz3474]

It's great that someone published that kind of material and provides all other sources, it's really better than paid courses on well known platrofms i used to did. Thank you Jeremy

[@JeremysITLab]

Thank you, Marcin :)

[@Kokevv]

Thank you for this amazing series. This is saving me tons of money and time. Thanks to you I can utilize this quarantine time to me benefit!

[@JeremysITLab]

Thank you, I'm glad you're using the time well ;)

[@arsalanazeem2373]

Truly best explanation ever. I have covered 17 videos and I have promised myself to complete all the videos after watching this one. Thanks sir.

[@anuarsgs1]

Hello Jeremy I hope you are doing well, Im Glad to find out in youtube a talented/professional person like you helping people to learn and grow up their knowledge, at this point of my life Im studying to become a Juniper Routing engineer, however I have my networking knowledge based with Cisco, im reviewing the networking basics back again and found your material and help me a lot to complete what im studying I hope I can have my certifications and keep studying learning so I can help others like you do, once again thank you for your support and help and God bless you!!!

[@AtrachewJemberie]

I passed my CCNA with flying colors 2 weeks back. Jeremy's IT lab is the best. For those who are studying, I would say Just keep on pushing. It is all worth it!!!

[@thedarkshadow7083]

Congrats on passing your CCNA with flying colors I'm curious, did you use the videos, labs, and Anki decks from Jeremy IT Labs only, or did you use other resources too? Any tips would be greatly appreciated

[@kimpaulson5542]

I appreciate how you split up the information into multiple videos! Makes it a lot easier.

[@Kisnowar]

Your clear pronunciation is appreciated. It helps in understanding the context.

[@JeremysITLab]

Thank you, I'm glad to hear that :)

[@nickDOTbloc]

this video marks the end of my CCNA journey

[@cornilpatidar]

lol why

[@moyura2]

13:16 A simple Google search shows Operating Systems use different TTL default values: MS-Windows 128 Mac 60, 64 Linux 64, 255

[@JeremysITLab]

Yep, being able to google is an essential skill for network engineers

[@BijouBakson]

The flashcards are what i missed in my days in school. I would have been a genius by now :). Thank you Jeremy.

[@JeremysITLab]

Me too! I would have definitely gotten higher scores on my tests if I used flashcards in school!

[@George-mk7lp]

you mean high school? you guys get network course in HS?? Which country is it?

[@BijouBakson]

@@George-mk7lp Flash cards can be used in any kind of studies. This has nothing to do with Cisco or networking. Flash cards is a studying tool.

[@George-mk7lp]

@@BijouBakson oh sorry I thought u mean network related flashcards .. I just heard that there are networking classes in some US high schools..

[@leongao5120]

​@@George-mk7lpMy canadian school district has some. We have a CCNA course. But it's probably a little excessive in terms of time 3 hours a day every day for a year is too much of a time commitment for me.

[@shw256]

Each router that a packet encounters decrements the value in the packet's TTL field by 1. So at each hop, the IPv4 header changes, and the router must recompute the value of the header checksum field. The Wikipedia article "Internet checksum" notes that there are quick ways to do this when that's the only change. (Presumably there's more overhead when packet fragmentation occurs.) IPv6 gets rid of layer-3 header checksums.

[@c7po457]

Whew! That was a lot, but I retained more than I thought I would. Jeremy, I love you, bro.

[@JeremysITLab]

Yeah there's a lot to remember...watch the video again if you have to.

[@LeoNux-um7tg]

@@JeremysITLab You should reply. I love myself too 🤣

[@rolandchanel]

this is fairly the best thing ive ever found on youtube EVER. thank you!!

[@JeremysITLab]

Glad you like it :)

[@brandelle13]

I must say, I am really enjoying those video classes much better than the online classes I have been attending. Gives me the Edge is grasping information. Many blessings & Thanks to you keep up the good work/videos.

[@JeremysITLab]

Thank you! Glad you like the videos

[@cydman4651]

You know what, I can't help myself to stop watching your videos specially on weekend because once I started one video I need to continue until I fell sleep or need to eat to pee! :D thank you so much Jeremy for such a wonderful and amazing videos, flashcards, and labs... one of the best channel I should say.

[@wayofsalaf]

your explanation is very clear jeremy. I just could say thank you for all these incredible lesson you've delivered

[@BabuBablu-hy2tw]

This is the best ever video on this topic. No one can explain ccna topics than you have done. You made these difficult topics too easy to understand and memorize. Thanks a lot.. Respect.🙏

[@jamesharris1613]

I love the series so far. I am on day 13 and am looking forward to completing this course. Commenting this on every video for the algorithm.

[@Don-Carillo]

Came here on Keith Barker's reccomendation ( CBT nuggets) and i am not dissapointed. Some of the best learning on youtube. Thank you

[@BijouBakson]

I forgot much of this stuff damn me! A revision always does the trick. Let's revise with the flashcard now! Thank you Jeremy.

[@JeremysITLab]

Always important to review! With so much information to remember, it's easy to forget some of it.

[@BijouBakson]

@@JeremysITLab Yup!

[@daniellety4736]

This is a most fantastic course! I have ordered the ENCOR course from your site as well! I have also taken the CCNA gold boot camp course. It is well thought out and structured but I find the presentation that you offer and your style of teaching to be far superior. Merci Jeremy!

[@realpride5981]

Dang it, today i was sitting like 2h on the flashcards to memorize the information. So far Ethernet Header and IPv4 Header things ware the hardest to remember :D Thanks Jeremy.

[@abdullahfitouri1675]

what helped me here is taking snips pf the lecture vid (pc screen shots), and using the app paint to cover sentences, and then put both pictures in anki !

[@kamalpreetsohal7012]

Thanks for teaching us today's lpv4 header, so understandable

[@JeremysITLab]

Thank you :)

[@engineerx7180]

Sir your videos are very helpful in gaining basic concept and learning. Thanks for your efforts. If you please provide the slides along with the videos, it would be be really helpful to reviewing it and remembering. Thanks ♥️

[@JeremysITLab]

Thank you, I will make a PDF of the slides and put it in the description. I'll do it this weekend if I can.

[@engineerx7180]

@@JeremysITLab Thanks A lot Sir for responding, you are really doing a great Job. Keep it Up Sir.!

[@JavitxuFILMS]

I promise to me if i pass the exam i going to convert in a new sponsor of your work. Congratulations, your work is excellent

[@JeremysITLab]

Thank you! Good luck!

[@glenntembo2693]

Compliments of the season J, Travel but now back and ready to roll. Thanks again for yet another bomb for more to come . Always grateful. Time to dive in

[@JeremysITLab]

Welcome back Glenn!

[@MoonHowler340]

Hi Jeremy! I'm currently at Day 10 of your CCNA course, but I've found it much more effective to learn the theoretical and practical material from you than from the paid course. Unfortunately, I need to participate in the private school's course as well to be eligible for the regulatory exam, because I need the certificate to apply to the accredited exam center. But, to say something positive, the two complement each other, and my instructor was surprised that I can apply what I learned from you in their course as well. I'm studying to become a junior system administrator, and we are covering CCNA RS1 and RS2 as part of the curriculum

[@elizondofamily3206]

This was an insane video but loved the learning! Onto my flash cards! Thanks Jeremy!

[@JeremysITLab]

Yeah there's a lot of info in this one!

[@Sadglory]

I'm just Impressed how brilliantly do you explain hard stuffs. Thank you for your work!

[@SAMSAM-up5nd]

I am addicted to your way of teaching. I don't find the videos from other instructors as detailed and brilliant. Kindly make a few videos on Wireshark

[@badger2258]

Thank you so much for these amazing videos. You do a great job of making things simple. This was a lot to chew, but you made it easy to understand. This is really helping me.

[@JeremysITLab]

Cheers, I'm glad it helped!

[@JulanEnglish]

6:15 I reckon it the maximum length of the field options should be 60 bytes in stead of 40

[@JeremysITLab]

Nope, 40 bytes is correct

[@bliss6607]

I was also confused at first, but since option is IHL>5, 15-5=10, 10×4 bytes, 40 bytes

[@SUMIT-sy7qs]

Again, this video is so clear, so understable. Thank you so much :)

[@JeremysITLab]

Thank you for all your comments :)

[@MuYang-ir7lu]

To fully understand it, I gotta have to watch it several times. This one is tough. Thank you any way.

[@rmsoft]

Well, so far so good. Your lessons are really right sized. As a software developer and having some knowledge of the domain, I'm progressing a little bit faster, but it's still really informative and I think, speed would not be the case after certain point. Anki cards are really useful piece. Thanks for your effort to share invaluable knowledge and I will certainly thank you after course is passed.

[@albertc7660]

Thanks Jeremy for your amazing videos! I started taking some Udemy courses on CCNA and your way of presenting the information is so much easier to follow. I find it helpful that you provided anky flashcards and lab sections.

[@muhammeddilshad6042]

That's a lot of information in one video...🤯 I had to watch it 3 times to understand..!

[@gsmuve]

Thank you very much. I know that I will rewatch this video however your explanation of things really simplify complexities of this networking world.

[@JeremysITLab]

Thank you :)

[@katofhyrule12]

Thanks! I had to watch all the videos for days 11 and 12 and then come back and rewatch this video before I could understand, but I do understand now.

[@Lynden_Price]

Fantastic video, I loved that you made examples to demonstrate fragmentation and showed how to view it in wireshark.

[@johnlomu]

Great job Jeremy, keep up the good work.

[@stenkytt4544]

Had to watch this two times, complete the anki flashcards and watch this video again. A lot of great information :D

[@yafeideng6718]

To be honest, this is world No.1 lecture!🤗

[@Pbist1998]

@Jeremy You are the best Networking teacher!

[@Bolee366]

The wire shark part was a good idea. I’m finally able to understand those fields when using it

[@mangimusa3175]

This was the hard one topic, but if you repeate it again and again + ankflash cards it becomes very easy....! Thanks fella..

[@jimwelch707]

Just a note with respect to the DSCP field. There are actually 8 bits available in that field. The first six are split into two sections, the first three bits are for IP precedence backward compatibility, the next three are for DSCP, and the last two bits for the ECN (which is used in WRED for QoS) you can see the eight bits when you show the field in wire shark at 19:56. Probably more information than required for CCNA but still ....

[@JeremysITLab]

You can call that whole byte the ‘ToS byte’, but I wouldn’t say the whole byte is the DHCP field, since only the first 6 bits are used for DHCP.

[@jimwelch707]

@@JeremysITLab All I was saying is the DSCP field contains 8 bits not 6. I don't argue dscp uses only the first 6 bits.. that being said, its your course, and I wasn't attempting to throw stones at your work. It's actually pretty good.

[@JeremysITLab]

@@jimwelch707 'DSCP' is the name of those first 6 bits, not the whole byte. I'm going by the RFC definitions.

[@JeremysITLab]

If you want a name for the whole byte it's 'DS', although I usually hear it still called 'TOS'.

[@jimwelch707]

@@JeremysITLab We're good - I've heard it called TOS as well

[@isaiahmaragalla]

Jeremy you have made the content so easy to understand. hats off for your incredible work. many many thanks

[@maxwellchessdotcom6952]

Folks, I'd like to welcome you to Jeremy's IT Lab.

[@hamimzia1713]

You mentioned at 14:04 that the protocol field indicates the protocol of the encapsulated layer 4 PDU. I understand that TCP and UDP are layer 4 protocols. But aren't ICMP and OSPF layer 3 protocols?

[@2AnDHLF]

The 8-bit Protocol field specifies the next upper-layer header within the data payload of the packet. These upper-layer protocols are identified using IP Protocol Numbers. The following is a list of common IP Protocol Numbers, as assigned by the IANA: 1 ICMP 2 IGMP 6 TCP 9 IGRP 17 UDP 46 RSVP 47 GRE 50 IPSEC ESP 51 IPSEC AH 88 EIGRP 89 OSPF

[@andym1594]

Comforting to see that others found this to be a truck load of data.

[@imjinaah]

0:26 IPv4 0:56 thing we'll cover 2:00 PDU review ----------------------- IPv4 header ------------------------ 3:56 Version 5:03 IHL- Internet Header Length 6:40 DSCP - Differentiated Services Code Point 7:30 ECN - Explicit Congestion Notification 8:08 Total Length 10:03 Identification 11:01 Flags 11:47 Fragment Offset Field 12:15 Time To Live 13:21 Protocol 14:44 Header Checksum 15:37 Source/Destination IP Address 16:08 Options ------------------------------------------------------------------- 17:14 Wireshark packet capture 24:24 things we covered 24:49 QUIZ!

[@eointhomas2914]

I was so overwhelmed watching this video for the fourth time!

[@alialiraqi2664]

Well im sure I will watch this tutorial 10 Times to be fit in the subjects............THANK YOU.

[@likhithsai-xr2xv]

around 10:53 @ Jermey's IT Lab says about mentioning the max ethernet frame size as 1500 bytes in previous videos. But I didn't find any in previous videos. Please any one confirm if this is true. I remember him mentioning minimum size as 64 bytes, by the way thanks for this great lessons.

[@sebasgeon666]

thought so too

[@immortalthought_]

Internet Header Length (IHL) The IPv4 header is variable in size due to the optional 14th field (options). The IHL field contains the size of the IPv4 header; it has 4 bits that specify the number of 32-bit words in the header. The minimum value for this field is 5, which indicates a length of 5 × 32 bits = 160 bits = 20 bytes. As a 4-bit field, the maximum value is 15; this means that the maximum size of the IPv4 header is 15 × 32 bits = 480 bits = 60 bytes

[@galiuzrohi4202]

God this is exhausted , Thanks Teacher for the excellent explanation .

[@emmanueltitang4190]

Need to go through again because am a fresher but great thanks for the time and energy.

[@JeremysITLab]

Thank you :)

[@veto4686]

Up till now I didn't have to watch them again. I even started quiting half way through an come back.. them little numbers are tough.. wireshark does help.

[@kauushal]

Thanks you so much for the valuable contains..... love from INDIA Mumbai

[@Uzt777]

It is getting more difficult than the other videos before, and I need to replay most of the it all the time. I need to keep saying to myself to: "keep on going and finish what you've started".

[@Didi2th]

I almost quit after this video, but we have to continue what we started

[@csp405]

5:28 What does it mean 4 byte increments? why and how are the 4 bits incremented? 7:39 What is notification congestion?

[@maksymperehinka4170]

The hardest day so far. Thank you for your videos.

[@lagranbestiapoop]

Buenos videos, Jeremy! Adquirí mucho conocimiento con estos videos. Gracias! Saludos.

[@JeremysITLab]

Muchas gracias!

[@florianflorian5839]

carry on big man god bless you. 👍👍👍

[@JeremysITLab]

Thank you sir!

[@bb1234697]

Incredible Information. Thank you so much Jeremy! You're the GOAT!! 🐐

[@arsenmkrtchyan4832]

Best Jeremy in the world!! A little robotic but I love it )

[@JeremysITLab]

No way, I'm not even in the top 10 Jeremys!

[@tenzinrabten7018]

So much to remember and its just day 10.

[@JeremysITLab]

You can move forward and then come back to this video later if you want!

[@nkkrishnan915]

In quiz question 2, perhaps (c) is correct as well. If the minimum is 5, zero indicates some kind of issue.

[@saravanakumar6758]

Great Explanation Jeremy. Thanks a lot

[@JeremysITLab]

Thanks :)

[@rjgeeks5857]

Very interesting n helpful video...for ccna students

[@JeremysITLab]

Thank you, I'm glad you think so :)

[@zoharsonego9376]

hey jeremy, can you explain please what is the differnce between an ipv4 header to an ethernet frame? I did not understood it clearly

[@maherhesham2975]

thank you for this amazing course and for wonderful explanation

[@julianwildauer]

Amazing lessons as always!

[@JeremysITLab]

Thanks Julian, I appreciate your comments 👍

[@rajneeshruhela7128]

Hey Jeremy. Your videos are really helpful, can you help me to understand ccnp ( routing &switching) how much time taken by you if someone deemands you regarding a ccnp video \

[@kangtaeho2534]

Hi Jeremy, thank you so much for the video! I just have a question: There is a FCS field in L2 Trailer. What is the difference between this FCS and the UDP/TCP checksum field? I guess the difference is that the FCS detects the in-transit error of a frame, whereas the UDP/TCP checksum field checks the errors in the data, and attempt to recover it? I just got confused... Thank you again Jeremy!

[@JeremysITLab]

They just check for errors at different points. The Ethernet FCS is checked and recalculated at each hop in the network on the route to the destination, the IP header checksum is used to check for errors in the IP header itself, and the TCP/UDP checksum is used by the receiving end to check for errors in the entire TCP/UDP segment (including encapsulated data). I'll talk more about TCP/UDP in a future video, including their checksums.

[@kimosaid3221]

Thank you so much Teacher for the excellent explanation

[@majidmushtaq4209]

so nice and clear cut information jeremy. thanks once again

[@abudawood9594]

this course is GOLD!!

[@akshaypratapsingh4865]

Hello, Please explain what does bad checksum means in the traces, captured on windows machine.

[@JeremysITLab]

Sorry, not sure.

[@IvoSantolaja]

Day 10 was awesome! Thank you Jeremy!

[@JeremysITLab]

Thanks Ivo! :)

[@zakariabouguenara3728]

What a video extremely perfect and very well explained Thanks a million

[@endalkshanko5162]

Thank you for this amazing series.

[@JeremysITLab]

Thanks, glad you like it!

[@muhammadhusnain3724]

hi i am glad to learn from you actully i having question what will be the whole bytes of IPv4header ?

[@Frissdas1207]

Keep the great content coming!

[@JeremysITLab]

Thanks for your support :)

[@abyss2026]

Every video was a 5/5 on the quiz, this time was a 1/5 XD

[@adegbiteanjolaoluwa999]

Hahaha same here😂😭