Everything Hosts do to speak on the Internet - Part 2 - Networking Fundamentals - Lesson 3

[@PracticalNetworking]

🚨📢 Update: *Module 2 is 80% complete* --> pracnet.net/networking 👉👉 Enroll now for *discounted early access* to the course 📺▶ Module 1 Playlist: pracnet.net/nf 💭💬 Join us on Discord: pracnet.net/discord _--- More info ---_ *Full Course Status: Module 2 is 80% complete* Hopefully you've come to realize that I put _a lot_ of effort into the content I create. I'm not a course creator that will simply turn on the screen recording and ramble, then call that teaching. I meticulously plan _every_ module and lesson to _maximize the learning and value_ for the student. To that end, it takes me a while to put together courses. After Module 2, I have about 8 more modules planned going deeper into Networking. I plan to make this course _the_ premier Networking course that gives _everyone,_ in _any_ tech discipline, the Networking knowledge they need to succeed. *Let's face it, everything is connected to the Internet these days, and understanding how that works will set you apart professionally.* *If you want to support the full course's development, then the best way to do that is to spread the word about this content* . By itself it already conveys _a lot_ of value. So sharing even just the 7 lessons (13 videos, all free) in this series will help whoever you share it with. Plus ... many online communities would greatly benefit from these videos. Think of all the Internet points you could acquire if you shared this series (karma, likes, follows, etc.) 😉 Use this link to share the full series: kzbin.info/aero/PLIFyRwBY_4bRLmKfP1KnZA6rZbRHtxmXi Or this handy shortlink: pracnet.net/nf Also, if you share it on Twitter or LinkedIn, please tag me =): twitter.com/ed_pracnet/ www.linkedin.com/in/eharmoush/

[@CPT_Pepper]

Thank you thank you!! (I now believe in miracles because I struggle with Ports, Protocols, & Services😂)❤

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Lots of love to you for making us for independent. The day I started watching your lessons is the day I realised all the hard earned money spent on my education went to waste as no teacher was as clear as your are when explaining these concepts on your channel. Thanks a ton for making life better of students like us.

[@PracticalNetworking]

Thanks for the kind words, Konark =). I'm really glad you got a lot out of these videos. Consider sharing them with your class mates or peers. I'm sure they'd appreciate your suggestions!

[@wwolfram33]

This ties together networking components in a easy to digest manner. Excellent presentation. It would have taken 8 chapters in a networking book to understand how these components work together. Thanks for the videos.

[@PracticalNetworking]

You're welcome again, Ward =)

[@Shank2485]

Best explanation ever. When i started searching youtube videos for basic networking training i was not satisfied with any videos after watching for few mins and when i found yours with titles “everything hosts do to speak on the internet “ , “everything switches do…” , “everything routers do” i decided this should be the best lessons on basic networking and these are exactly what i wanted to know.

[@PracticalNetworking]

Glad you've enjoyed the series, Shankar =). Hope Networking makes more sense now!

[@LuckyYouDude]

Thanks Ed. You are the BEST teacher when it comes to Networking fundamentals on KZbin hands down. Can't wait when you put any lessons out on Udemy or any other platforms. Thanks again for all the hardworking and time you put into these wonderful videos. I personally very much appreciate all of it!!

[@PracticalNetworking]

Thanks for being a loyal subscriber and for all your support, RiseOfTibet =). I appreciate the kind sentiments.

[@nithinpv8884]

The best videos on networkin basics, i have watched so far. Thankyou. PS: I liked the use of the "header heaven" 😂

[@PracticalNetworking]

Yes, that always makes me snicker ;) Glad you enjoyed the series !

[@antonyrichard369]

I am unable to stop listening to your lectures.. it's so simple and cleanly categorised and very effective.. i am having an efficient learning.. Thank you so much for your learning materials... 🙏🙏

[@PracticalNetworking]

You're very welcome, Antony =). Hope you continue to enjoy these videos! Could you do me a favor? Do you mind sharing this video on Linked In, Reddit, Twitter, Facebook, or any other social media you use? As an independent creator, that would be an _enormous_ help, and I would appreciate it _greatly_ .

[@VizDad]

Here I am 3 years later loving this material. I’m learning more here than anywhere else! Will definitely be supporting your page. Thank you for putting these courses together!

[@learningchannel274]

Thank you so much for this. This is by far, the best series in Networking fundamentals. Keep up the good work.

[@alonsosolano5117]

Thank you so much for the free information. The way that you explain makes everything easier to remember.

[@PracticalNetworking]

You're very welcome! Glad it helped you. Consider sharing these videos with others who might appreciate them as well =)

[@adedejiemmanuel1]

I am watching this again, like new wine, its evergreen. Thank you.

[@rampallychandrakanth4139]

sir what a content. 10 mns of a video will understand the whole concept of layer 2 and layer3

[@bbqconstruct9641]

Each of these videos is getting the algo pampering like and comment, something I've never done before. Great teaching!!

[@ashosaurus2140]

This is brilliant - very well structured, very well explained, addressing all concepts and jargon with clear and easily digestible explanations - an absolute masterclass of teaching. Just amazing.

[@PracticalNetworking]

Glad it was helpful! Thanks for the kind words.

[@temitopeekunnusi361]

After watching several videos on Networking, this one is the best so far. I can teach it to a 5 years old convincily. Thank you for sharing your knowledge freely.

[@rotrose7531]

Simple yet most efficient. Please do not stop creating these otherworldly materials for us.

[@PracticalNetworking]

[@mohaimenulimam233]

Changing career! And these videos are helping like a brother.

[@sanchitpaiyala4791]

by far the best video on networking on KZbin. Tons of Love & Likes

[@CPT_Pepper]

🎉🎉😊thank you so much!! Your videos are a gift from the "IT Gods" for visual learners. The animation is splendid!!❤❤😊👍🏽

[@AhmedAshraf-xg1nj]

The best networking series I've ever seen. Keep up the good work

[@PracticalNetworking]

Thank you for the kind words =)

[@kishorek8578]

Thanks for videos, they are very clear than any text book, it makes our learning easy and save time & energy, thank you!!

[@PracticalNetworking]

Glad you enjoyed it, Kishore. Please tell your colleagues =).

[@shepherd7583]

So glad I found this channel. I have a big ol' Cisco book that I've been dreading for 3 years now. Your first 2 videos basically summed up the first chapter of that book ❤

[@aruizsilva]

You are providing an excellent foundation for the upcoming video series. Looking forward to it. Thank you very very much. Keep them coming!

[@PracticalNetworking]

Thanks Antonio! Hoping to get the next video out in the series this week!

[@sweetmrpotato5467]

Definitely one of the best explainations on the internet. Thank you so much for this series. Cheers.

[@PracticalNetworking]

Thank you for the kind words =) Could you do me a favor? Do you mind sharing this video on Linked In, Reddit, Twitter, Facebook, or any other social media you use? As an independent creator, that would be an _enormous_ help, and I would appreciate it _greatly_ .

[@sweetmrpotato5467]

@@PracticalNetworking Absolutely. I have a bunch of Network-heads for company. They'll definitely have a look ^_^

[@PracticalNetworking]

@@sweetmrpotato5467 Awesome. Thank you for your support =). Much appreciated!

[@artursweden3653]

You are a genius that make things look so easy to learn.

[@kallikantzaros]

This is so easy to understand now. Thank you very much.

[@PracticalNetworking]

Thank you, F10. Glad you enjoyed it!

[@alibeehzadzai3029]

lots of love and respect . You have make things very clear and easy to learn. Wish you all the best.

[@shujauttali2608]

This is really Practical Networking. 🎉🎉🎉 Please make a CCIE Security Course for us, the people who love listening you.

[@amtawfik140]

This is amazing!! You are a great teacher. Thanks for your explanations so simple to understand

[@VTS-lelovsky.]

Just wanted to say that I love the cute computer illustrations 🧡💛🧡 Great explanation, thank you!

[@jasonwoods1236]

Great content, and a very well explained.

[@PracticalNetworking]

Glad you liked it!

[@Addistoday]

best regards from Ethiopia and many thanks. i owe you one!

[@nuamaaniqbal6373]

Thank you for this beautiful playlist!!

[@PracticalNetworking]

You're welcome, Nuamaan! =)

[@khubaibsiddiqui7144]

You are the best of best❤ Really explained in a unique way💫

[@wwolfram33]

I would like to know how a Windows host speaks to the Internet and to other directly connected networks when it has multiple interfaces (NICs). The logic using the PC's routing table explained in a simple manner would be great. Thanks again for the videos.

[@PracticalNetworking]

Great question! Essentually, the Routing Table will determine what interface to use when sending traffic... just like a Router's Routing Table. Each NIC will have it's own set of Routes. It will make more sense when you get to the Router videos (Lesson 5).

[@dineshsthanki5203]

Thanks. Very well illustrated and explained. Need similar videos on Bluetooth

[@PracticalNetworking]

Thank you, Dinesh. Glad you enjoy it.

[@MadaRook]

I really appreciate your lessons, thank you

[@pradeep2662]

Thank you for your service. *salutes*

[@deepakjohn6426]

Thanks a lot for your videos. The topics are greatly explained.. Subscribed !..agree that what i learned in engineering is waste of time and money when compared to this...i draw tcp ip and udp flows in examination without understading how data flow on network. I think books need to be updated with such practical explainations rather with waste theory which only helps to score marks.

[@PracticalNetworking]

Hi Deepak. Thank you for the kind words, glad you enjoyed the way I explained it. Yes, I agree, it's a shame so much "training" is separated from the practical aspect of what is being learned. It's a great disservice to the learner.

[@HusseinElsherbini-f3v]

@8:00 you mention that the host uses ARP to resolve the router's "IP Address" if it is attempting to speak to a deviceon a foreign network. don't you mean it uses ARP to resolve the router's MAC address since it is already configured with a default gateway IP

[@billpalmer7109]

As always Awesome job with outstanding presentations. Thank you so much an keep up the great work. I always look forward to watching your content. LilManGinger

[@PracticalNetworking]

Thanks Bill. =) I appreciate your support!

[@silvanabongiorno3292]

Great courses on networking!

[@moularaoul643]

Great work .

[@alexandrkovalsky1711]

great video!

[@kappi4882]

Good Job 👍🏻

[@PracticalNetworking]

Thank you =)

[@shivangitomar5557]

Amazing video!!!!

[@vladislavkaras491]

Thank you for the video!

[@tokogray]

Loving the lessons! and are looking at doing the if its available. Trouble is I can seem to find a link to it (outside of the under construction page). Can you tell me if this course is up and running. Thanks

[@PsychoKiller24601]

Very much enjoying the course. Apologies if i missed this, just wondering, how does a host know if the ip they want to contact is local or foreign? Thanks!

[@faizanfarooq3903]

2:08 what if foreign I. P has same subnet mask what will host do in that case. . Is that possible.... For e.g ...host a has 193.10.10.3 ...i.p and is in Australia...... And host b has 193.10.10.28 and is in USA..... They both have same subnet mask 255.255.255.0 so what happens here in this case what will host a look at and distinguish ....considering subnet mask is same.....

[@PracticalNetworking]

You're asking about hosts with similar IP Networks, not just similar Subnet Masks. In any case, they wouldn't be able to communicate because they would each continually try to reach each other "locally". More details here: www.practicalnetworking.net/stand-alone/vpn-overlapping-networks/ (sorry to just see this comment, KZbin had it filtered because it contained an IP address... thanks KZbin)

[@dasentertainment2175]

Well explained !!!

[@PracticalNetworking]

It's been fun seeing your comments as you progress through these videos!

[@jaikishank]

Thanks for all your Videos. I had watched all of them related to the OSI model and its components. Your explanation is awesome and cannot be made crystal clear way than your videos. It was a great experience to get the concepts clear after exploring many sources. May God bless you.. Do you have plans to publish videos on IoT and related stuff ????

[@PracticalNetworking]

Hi Jaikishan. Glad you enjoyed the content! Thank you for the kind words. I have lots more ideas for content to produce. =) The next series of videos I'm going to be releasing will focus on Cryptography and SSL/TLS. Stay tuned for that =)

[@peaceful-relaxingmusic3887]

6:00 does the router sent a arp request to host C, for C's MAC adres

[@PracticalNetworking]

Yes =). But that process is outlined in the "What does a Router do" video (lesson 5) of this series.

[@peaceful-relaxingmusic3887]

@@PracticalNetworking thank you

[@pd1259]

A hypothetical question, could it occur (e.g. due to careless configuration) that the network Host A is on has the same network portion of the IP address as the network Host B is on, which would make Host A think that Host C is on the same local subnet, when it actually isn't? How would such a situation be resolved? Thanks!

[@bobbymazumder8769]

So very grateful to you !

[@akedintm]

thank you, let's boost the algorithm!

[@shubhz.sayzzz]

THank you so much for great content but I have some doubts. DO switches have mac addresses? If they have then how host speak over switches? DO all the devices on local network receive the ARP requests?

[@PracticalNetworking]

Switches do have a MAC address, but it is unused in traffic going through the switch. I show you how that work in this video: kzbin.info/www/bejne/d5myhmWbhNWgjpI (specifically, I talk about data going THROUGH a switch vs TO a switch at 8:54)

[@NobixLee]

Hey there, do you have the slides on the videos available? If like to print some of them to put on my wall.

[@saisiddardhavoruganti640]

Great course buddy 🥳, any update on the full course ?

And what does the router do to figure out the mac address of the final host? Does it use ARP as well and broadcasts it to everyone in the internet to find the mac?

[@7tonycloud]

hi your tutorials are very helpful. just wanted to know is the IP address of a device stored on the device or is it determined by the host. how does the host know the clients in address

[@PracticalNetworking]

Glad you are enjoying these. It could be both. You can store destination IPs on your device locally (search "/etc/hosts" file for more details). Or you can determine them as needed (using something like DNS).

[@aniletnirmal8327]

Thank you so much 🍀

[@marcr5595]

I have a question regarding the L2 header when the router sends the packet to the next router. How does the router find out the MAC address of the next router?

[@chrism3790]

Why is ARP necessary though? If hosts/routers are locally already uniquely identified through their IP address, I can't see the benefit of having a separate MAC address. What am I missing?

[@chrism3790]

In case anyone is wondering what the answer to this question is, I googled a little bit and found that MAC addresses are needed to establish connections to new hosts. When a host joins a network, it has no IP address. There needs to be some sort of static identifier at the very beginning, otherwise the router would have no way of knowing who it assigned an IP address to. I ended up reading about DNS/ARP spoofing and DNS poisoning, very interesting topics.

[@IliyaDamyanov]

Super video.

[@DailyLearnings1]

This was good however it didn't covered up multiple parts such DNS resolution, routing table on hosts and ofcourse cases of multiple NIC on host 👍 Thank You

[@PracticalNetworking]

DNS will be covered in the full course. So will NIC bonding. I wanted to keep this first module very simple though. Routing tables will be (briefly) touched on in Lesson 5. Glad you enjoyed it!

[@DailyLearnings1]

@@PracticalNetworking Yes Indeed it was nice session If so is the plan then you may have to create those videos and then again provide reference of them in this video 👍❤️

[@Vasko10100]

@@PracticalNetworking where can i buy the full course?

[@TheUCKO2]

Was the full course ever developed if so where is it?

[@orochimaru527]

Assuming Host A wants to get information to a different network Host C across a single router, once the router "takes over" after Host A's data gets to router and router sheds the L2 header, does the router also perform an ARP request to get Host C's MAC address for the next hop? If so, what would the L3 and L2 headers for the router's ARP request look like? Src IP , Dst IP , Src MAC , Dst MAC ffff.ffff.ffff? Hope this makes sense.

[@PracticalNetworking]

Great question. I answer that in a future video in the series. Check out the "Router" lessons in this playlist: kzbin.info/aero/PLIFyRwBY_4bRLmKfP1KnZA6rZbRHtxmXi Specifically, the L5b (Routers, part 2), I illustrate exactly your question. Hope it helps!

[@orochimaru527]

@@PracticalNetworking Awesome, video cleared it up nicely. Thanks.

[@schizoscope8703]

Thank you!

[@SuperOnlyP]

I would suggest using Patreon so that people can support you to create more educational content. Thanks

[@PracticalNetworking]

I'm unsure if Patron can offset living expenses for full time course creation. But I appreciate the sentiment.

[@pratyushpradhan9654]

Thank you so much,

[@PracticalNetworking]

You're welcome, Pratyush. Thank you again.

[@K4pitell]

Thank you very much !

[@alessioscippo596]

ARP operates on a LAN only, it's a broadcast request with a unicast answer, ok. And what protocol is used on the Internet to resolve ip to mac address?

[@mariamfirdous8456]

Is NIC card responsible for calculating that destination IP is on foreign network and data need to be send to the gateway IP ? also arp packet is generated by NIC card? it seem arp is a local protocol running between the hops only.

[@PracticalNetworking]

The Operating System does that calculation. ARP is also generated by the OS. And yes, ARP is local, only for devices on your local network. It can't be used to discover MAC addresses in foreign networks (nor does it need to, that wasn't it's purpose).

[@mariamfirdous8456]

@@PracticalNetworking cool, i am watching this series, i might need to watch it couple of more time to get my basic strong. this is such a good series. ty.

[@PracticalNetworking]

@@mariamfirdous8456 Feel free to join us on discord if you have questions: pracnet.net/discord Glad you're enjoying the series =)

[@stardust4evah]

The header heaven took me out lmaoo

[@nabilalanizi7457]

Thank you Sir

[@munirajulu]

Thanks Sir

[@PracticalNetworking]

Welcome!

[@khargos7602]

may we all one day retire to header heaven😌

[@Aliyar136]

May god make us do good deeds before that 😊

[@EstebanDuPlantiers]

ACK! RST in FIN!

[@Kagiel]

Jesteś cudowny!

[@AliTwaij]

Brilliant

[@PracticalNetworking]

Thank you, cheers Ali.

[@AliTwaij]

@@PracticalNetworking you deserve it mate , its really clear and concise. Thanks again.

[@chandantiwari4857]

Sir expecting video about IP TCP UDP header

[@PracticalNetworking]

TCP and UDP will be covered in detail in the full course. =)

[@muzafarmehrajmisgar2664]

great content ...can u share ppts

[@PracticalNetworking]

I'm afraid I can't share the PPT, those are the IP for this content. But you're welcome to share these videos wherever you need to =)

[@electricalstuff259]

Wouldn't it cut bandwidth in half if the router just went off and did its work before then telling Computer A its MAC address at the same time as delivering the destination IP's response? Instead of going A -> Router, Router -> A, A -> Router, Router -> B, we could just go A -> Router, Router -> B.

[@joao_ssouza]

These are two different things. The router cannot send data to host C using an ARP request, since it doesn't carry any data at all. Notice that the process A -> Router -> A only happens once, after this the router's MAC address is cached.

[@PracticalNetworking]

João 's answer is spot on. The ARP resolution only needs to happen once, and then the answer is cached. But to answer your question, I have a follow on question. How would Host A send something to the Router? What would it use in the destination MAC field? A possible answer is to use a broadcast... but then everyone on the network gets the data payload, which has a security implication. ARP is a good middle ground. The broadcast ARP Request is not sensitive (it's just asking for a MAC address), then the data payload is sent directly to the Router.

[@electricalstuff259]

@@PracticalNetworking Great answers thanks guys. This is the best networking content i've ever seen. Once i get money i'm gonna sign up for the premium stuff.

[@PracticalNetworking]

@@electricalstuff259 Glad to help =) The full course is in development. In the mean time if you want to help support the channel, please share a few links to this content online somewhere =). Much appreciated.

[@mittenwald3679]

this deservers 1 mio likes, lesssgo !!!

[@SK-qn5ry]

Can anyone explain how Router ip address configured to default gateway. What is gateway? How many gateways be possible for single router? Suppose I have buy router and want to connect to 8 subnets How to do it?

[@JJFlores197]

The gateway is the device that routes an IP packet to its next destination outside of the network. In other words, its a router. The default gateway is usually the routers IP address. It is used by devices inside of your network to know where to send packets if the destination is outside of the network. I don't know if there is a hard limit on the number of gateways, but you have to configure your router to use VLANs in order to use multiple subnets.

[@DelaRenta1]

Thanks

[@frempongadarkwa2232]

If you dislike this video then there is something wrong in your head.

[@PracticalNetworking]

Ha, love it =) Thanks for the kind words, Frempong. PS: Newest video in the series just released! kzbin.info/www/bejne/sJ7bfZpqn7tjqtU

[@mihiragrawal1870]

Correction: there is something wrong in your header

[@Chuchu2709]

The header has been such a good boy and gone to the header heaven .·´¯`(>▂

[@PracticalNetworking]

I was hoping people would get a laugh out of that ;) Hop to Hop / Point to Point are probably interchangeable. There isn't formal definitions for either. Some might consider Point to Point specifically the wire itself (meaning your host to the switch), where as hop to hop (at least how I am defining it) explicitly means from NIC to NIC (which might span multiple wires if multiple switches or hubs are involved).

[@Chuchu2709]

@@PracticalNetworking Thank you for taking the time replying /answering my question. Really appreciate it!

[@dreabazarte2014]

I wonder, where will bad headers go if not in Header Heaven? 🤔🤣

[@rahulsingh-hb7gr]

Hiiii

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my internet bill is worth every penny

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Do we have a name on LinkedIn or tweeter Facebook we can tagg you to atleast appreciate the work you do. I have been glowed to your work for 5 straight days now. And people I have shared with say same

[@PracticalNetworking]

I'm not really on Facebook, but I am on Twitter and LinkedIn =). Twitter: twitter.com/ed_pracnet LinkedIn: www.linkedin.com/in/eharmoush/ Thanks for being willing to share!

[@mohaimenulimam233]

Changing career! And these videos are helping like a brother.

[@PracticalNetworking]

So glad these are helping. Good luck with the career switch !

[@subee128]

Thank you very much