🚨📢 Update: *Full Course is Under Construction* --> pracnet.net/networking 👉👉 Enroll now for *discounted early access* to the course and a chance to help shape its content. 📺▶ Module 1 Playlist - Networking Fundamentals: ua-cam.com/play/PLIFyRwBY_4bRLmKfP1KnZA6rZbRHtxmXi.html 💭💬 Join us on Discord: pracnet.net/discord _--- Original Comment below: ---_ *Full Course Status: Wait and See.* 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. If I'm going to dedicate the time, resources, and energy to putting this full course together, I need to know that there is enough interest in the full course. I'm rating that by how wide a reach this series achieves. *If you are interested in seeing the full course developed, then the best way to bring that to fruition 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) in this series will surely 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: ua-cam.com/play/PLIFyRwBY_4bRLmKfP1KnZA6rZbRHtxmXi.html Also, if you share it on Twitter or LinkedIn, please tag me =): twitter.com/ed_pracnet/ www.linkedin.com/in/eharmoush/
@@adedejiemmanuel1 It's just a place for people learning networking to gather. I'm in there often enough if you also want to ask follow on questions. I also use Discord for the student chat for students of my courses: classes.pracnet.net/
There are a lot of great networking tutorials on UA-cam but this series is by far the best. You explain everything so clearly and with great examples to help reinforce the knowledge. Thank you so much for taking the time to make these videos, they are absolutely fantastic.
Thank you, Pete. I appreciate the kind words. Could you do me a favor? Do you mind sharing this video on Linked In, Reddit, Facebook, or any other social media you use? As an independent creator, that would be an _enormous_ help, and I would appreciate it _greatly_ .
Criminal you're not doing the entire course. I'm entering back into university and this is such a flawless tutorial from top to bottom. I'd have no issue paying for the full course.
Hey Practical Networking.. I just wanna let you know, that lately I've been trying to learn about networking to help better understand a career I want to go in. I am so thankful that you are here to help us learn about this. I am understanding practically everything (with research here and there) easily and I'm becoming more comfortable pursuing this kind of career. This is as far as I am now, and I want to say thank you again for providing us with this information and illustration. I have a lot of patience, and I have been doing the same job for almost 13 years now with fast food and I've always been interested in computers and technology since I was a kid, even automotive which may have some common deployment since cars are becoming more and more electronic. This seems like a fascinating field and I will keep pursuing it.
Hi Onyx, thank you for taking the time to write out this comment. I am _thrilled_ that you are considering Networking as a career and I am honored that my videos have helped you in that journey. It is a very rewarding career with lots of opportunities, and I wish you all the best in finding them. Cheers, Onyx, and good luck!
You can absolutely do it! I used to work odd jobs, gas stations, grocery stores, etc. having no education. Then I became unemployed and was on welfare for a while. That was the point when I decided to do something different, and I started pursuing the IT carreer. I now work as an IT consultant, working very comfortably from home most of the time, earning a decent wage. If I could do that, I think anyone could.
Okay. I knew nothing about communications and how internet worked in general. Your tutorial playlist on networking is GOLD, and i seriously mean it ! Now, i can think of how i can architecture my network at home, how i can create my personnal server and how i can connect to it... Even from another location, through internet ;) Thank you a LOT !!!
Whoa Nicolas, thanks for the kind note =). It's almost as of the intent of this series was to provide a *practical* explanation of *networking* . It's _almost_ as if that's the whole purpose of the channel ;) In any case, glad you got a lot out of it. =)
By far one of the best series on Networking I can say. Whoever wants to know the basic and in detail concepts of networking can simply ignore other contents on you tube and just watch this one. It gives you all necessary knowledge with great examples. Hey @PracticalNetworking, Thank you so much for posting this tutorial and helping us in understanding the concepts in simple and best way. all content I was searching about networking in the past two days, I have got it in this series itself. I will definitely recommend this to others and share the videos as we.. Thanks once again for posting this kind of tutorials which are helping us a lot.
One of the most practical series and so easy to understand difficult subject. Please create the full fundamental course, I think whoever will watch it, definitely get benefit from it. Also, if you can have some lesson on i.e Network types on VM, i.e. NAT, Host only etc work & How Kubernetes and WAN technology works in basic , then I will be grateful to you. Thanks a lot
Please continue creating more networking videos. You explain it in such a way that I always understand by the end. The best out there for me. Would love to see you cover all the aspects. Thanks for spending the time to put these together for free!
First of all I would like to thank you for posting such a great playlist on youtube for free. You are an amazing person. I got a question relating to this video. At 2:06 you mentioned that we can get rid of IPs on this layer. Let say, I'm going to ping computer 1 from computer 2 and are both in the same network connected via a switch. How can I ping computer 2 then If there's no IP? we can't ping a device using its MAC Address.
You're very welcome, I'm thrilled you've enjoyed. Here when I said we can "get rid of anything IP related", I meant only in the illustration. In the background, however, IP is still required for communication. Remember in this video I was trying to remove all extra variables so we could focus purely on switches and what switches use to make forwarding decisions.
I've spent money on udemy to understand "nothing" (i mean i've learned the hard way with teachers explaining the "hard" and "complex" way" and i've found that u have the best wording to explain everything so easily and understandable. Its not easy to have this ability. >Thanks
Crystal clear explanations and definitions of everything here. I think it would be difficult to NOT understand the concepts after you've explained them. THANKS Ed! (:
@@PracticalNetworking yes. I completed. I am not from a networking background and it was a great value addition for me. Your channel has been a Holy grail for me regarding networking. Many Thanks.
@@jaikishank I'm happy to hear my content has helped you in your journey. =). 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 / or amongst your peers? As an independent creator, that would be an _enormous_ help, and I would appreciate it _greatly_ .
The next video in the series is available here: ua-cam.com/video/G7GyWjJtjNs/v-deo.html Otherwise, another project has come up that has to take priority over these videos. Regretably, the videos on Routers and Routing will have to be pushed back a few weeks. Creating these videos takes significant time to design, record, and edit. I wouldn't want to rush the process at the possible cost of quality. For what it's worth, the series is loosely based on an article series I wrote some years back. If you need the info sooner, a lot of it is available here: www.practicalnetworking.net/series/packet-traveling/packet-traveling/
Hi Great video. Except that I have some remarks. Normally from what i can understand from the previous vids is that the process that you have described is related to ARP. Basically when we want to initially send data from A to D, L3 and L2 are created. But in L2 we miss the DST Mac@. Hence, we send an ARP request. It is that ARP that is sent in a broadcast manner (Flooding), to resolve DST IP@. Host C and B will discard the frame and only D will respond unicast. Meanwhile MAC table of the switch is populated with both mapping of port 5 an 8 to A's and D's Mac@ respectively. The confusion is that, are you describing here the process of sending data after aqcuiring D's Mac@ through ARP, or are you describing the ARP process? Because again we cannot know mac@ of D but after doing the ARP (host started knowing this), and the flooding normalling is done in ARP process (we dont know yet D's Mac), so there is a confusion here. If you were describing ARP process, then initially D's is unknown. and corrrect me if i'm wrong. It is that if i understood well, if we know the mac@ of D, then the MAC table is already populated with all necessary information to carry out hop to hop delivery. Because we will already have used ARP Thanks
You're on the right track. Remember, the Switch's MAC table is completely independent from the Hosts' ARP table -- they do not share information and/or help each other. The switch will flood if it doesn't know a particular MAC. The host will initiate ARP if it doesn't know a particular MAC. More details on how it all fits together in the final video in the series: ua-cam.com/video/YJGGYKAV4pA/v-deo.html (but I'd recommend not skipping lessons and watching all the videos in the series)
@@watsonsmicrocomputers9297 Glad the answer helped. As a teaching strategy, I opted to avoid talking about ARP when discussing switches, since a switch never initiates an ARP request. A switch only Learns/Floods/Forwards, depending on whatever packets show up. But, I can see how that would lead to this question being asked. Makes perfect sense.
@@PracticalNetworking I totally agree with your strategy. As a teacher, myself, I always (when effective) try to anticipate the questions of my best and worst students to briefly head them off, so they are not burning up bandwidth being stuck on that question. Questions that lower their processing power or inhibits it completely when talking about the rest of the information coming their way. But most definitely, like you said, without removing the focus from the topic at hand.
Perfect explanation with visuals. Thank you so much for investment of time on this. One question here is acknowledgment of data received to a sender is happens automatically ?
One question, wouldn't the flooding be done as part of the ARP process? I.e if A already knows Ds mac address, it must have learned it via an ARP broadcast, in which case the frame would have been flooded out of all ports except the one it was received on. So wouldn't the switch take that opportunity to build its mac address mapping for A and D so it doesn't have to redundantly flood the network at a later time? Is this example a scenario in which the switchs' port mapping table was lost/reset after an earlier ARP broadcast? I'm new to networking so I'm not sure of all the scenarios in which a switch will flood the LAN. Thank you!
Correct. I talk through that in the next video in the series =). For this one, I wanted to start from the position of Host A already knowing Host D's to keep the Switch illustration as simple as possible.
Glad you've liked it =). If it isn't too much trouble, you probably know others that could benefit from understanding networking. Shares are greatly appreciated =)
@PracticalNetworking, I have one doubt If you please clarify, A sent frame to D, which means that A has L2 information, having L2 information basically means that ARP has been already done. So in the process of ARP switch did Learn the MAC of A and D. So which basically implies that switch table does have information of A and D mac address. Which basically means flooding never occurs. Am I missing something? Please tell me
Around 2:20 in the video I explain we are skipping the arp process for the example to focus on only how the switch works. There's an example in lesson 7 of the series which includes both arp and switch learning together.
More details here... still waiting to create entire course: www.practicalnetworking.net/index/networking-fundamentals-how-data-moves-through-the-internet/
Thanks a lot! But I was wondering just one little thing. You intentionally left ARP out of the equation in order to not repeat yourself what has already been said. So if a sending host already knows the L2 details of a receiving host, ARP must have been performed before. So shouldn’t then the MAC Address Table of the switch already have ‘learned’ the connection details (port - MAC address) while ARP was performed in the first place? Thanks!
So, yes... if the host had sent an ARP request, that would be enough to populate the MAC address. In my video I was skipping ARP entirely, as if the host some how, magically, already knew the MAC address it was trying to speak to (i.e., ARP never happened). Hope this clears it up.
Great explanation!!! I just had a question. If switch knows about port 5 and port 8 and a frame is intended from port 8 to port 6 then will the switch flood the packet and send a copy of it to port 5 also? As it have entry of port 5 in mac table and knows its not the destination for the frame.
Great question. YES, the flooded frame will also go out port 5. The reason? Outside port 5 could be a host directly (as pictured) _or_ outside Port 5 could be another Switch, upon which Host 5 is residing. It will make more sense in the next lesson when I show you how it works with multiple switches: ua-cam.com/video/G7GyWjJtjNs/v-deo.html
Are switches built in these days to routers? I am trying to understand why we would need switches if a router (a TP link device for example) can implement this function within it.
Yes. A "switch" is a device who's primary purpose is "Switching". And "Switching" can be done by many difference divices. Your home wifi router does both "Routing" and "Switching" (as the described in the respective videos)
@@PracticalNetworking i am sorry .. I was about to put "Thank you is just not enough" .. typo 🙏 .. anyways .. continuing your lectures with full enthusiasm..
If you are not able to explain it to a six-year-old child, it means you don't understand it enough. YOU ARE THE MASTER OF YOUR CRAFT You could teach IT Network to a snail. For sure.
Aren't the ARP request for the MAC address of Host D supposed to do that 'Learn' & 'Flood' part of the Switch? I know the demo is based on already knowing the MAC of Host D, but I'm curious about when it didn't.
Yes. Normally, the host's ARP resolution would be used for the switches' LEARN process. For this demo I wanted to reduce variables so I left out ARP for the sake of creating an easier learning series =)
So if ports on the switch are swapped, during the "forward" action, does it also perform a verification that it's the correct MAC? And if it's not, then it starts over from the "learn" action?
When a port is disconnected, it triggers clearing the MAC address(es) associated with that port. So when they are "swapped", the MAC addresses table (for those ports) are empty, and yes, everything starts over with the Learn / Flood actions.
I have a few questions about a scenario: 6:14 - It’s assumed host D will send something back to A, and that’s when/how the switch will learn to populate the MAC table. Is there a scenario where host A sent something to D, but did *not* need/want a response back? If so, what would happen? Would D simply get their data, and the switch would learn nothing? Would D send information back to the switch so that the switch could populate the MAC table? Would the switch just not learn the information yet?
Great question. Yes, there are scenarios where Host D does not send a response. That all comes down to the application being used. In the case of Ping, a response is expected. In the case of Syslog (for example), Host A is simply sending log events to Host D, and Host D is not confirming reception. Again, it all depends on what the application requires, so there could absolutely be a situation when Host D isn't expected to respond. As for the rest of your questions... you are right, if Host D doesn't send anything, the Switch will never learn of it's MAC address. In practice, however, almost every host when plugged into the network starts sending out probes to discover neighbors or "call home" (think, windows updates, or background weather apps, or clock syncs, or stuff like that). Most hosts these days are very "chatty", so almost immediately once they are connected the Switch will learn their MAC address. I'll also mention... hosts typically also immediately send some Gratuitous ARPs when connecting to a network. This also will populate switch MAC tables. Details: www.practicalnetworking.net/series/arp/gratuitous-arp/
I am slightly confused. Previously, when covering communication within the same network you only mentioned L2 headers and the MAC address. So why all of a sudden do we need both the IP address and the MAC address for switches to facilitate communication between devices on the same network?
If you are talking about what is being discussed around the 0:50 mark, it's meant to mean that the HOSTS need to have both an IP address and a MAC to talk to each other, not that the IP address itself is used by the switch to facilitate communication. In the end any host needs an IP address, as it needs to validate it to confirm that it was the intended recipient of the communication once the packet reaches level 3 of the ISO/OSI stack
Thank you for your videos, they are a great resource. In this video we assumed Host A knows the MAC address of Host D. What if it didn’t? Is it possible for the switch to ‘Learn, Flood and Forward’ during the process when the ARP request/response is made?
Thank you very much for these videos, which are more than wonderful. I have a question about the switch. does the MAC Address table start populating after the first broadcast, for instance, assuming an ARB request sent for the firs ttime from the computer A? If yes, then why the switch is not start learning from the first broadcast of computer A. Thanks again for this awesome contents.
Glad you enjoyed then. Yes, the MAC address tables starts populating from the first _anything_ that is received on the Switchport. In the example I used Unicast to keep it simple to teach Switching. But the final video in the Networking Series will outline what you are describing. Cheers =)
Doubt: But why simple connecting the cable the Nic delivers the Mac Address or turning the host on? Or in the flooding other ports teach their appropriate Mac address?
🚨📢 Update: *Full Course is Under Construction* --> pracnet.net/networking
👉👉 Enroll now for *discounted early access* to the course and a chance to help shape its content.
📺▶ Module 1 Playlist - Networking Fundamentals: ua-cam.com/play/PLIFyRwBY_4bRLmKfP1KnZA6rZbRHtxmXi.html
💭💬 Join us on Discord: pracnet.net/discord
_--- Original Comment below: ---_
*Full Course Status: Wait and See.*
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. If I'm going to dedicate the time, resources, and energy to putting this full course together, I need to know that there is enough interest in the full course. I'm rating that by how wide a reach this series achieves.
*If you are interested in seeing the full course developed, then the best way to bring that to fruition 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) in this series will surely 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:
ua-cam.com/play/PLIFyRwBY_4bRLmKfP1KnZA6rZbRHtxmXi.html
Also, if you share it on Twitter or LinkedIn, please tag me =):
twitter.com/ed_pracnet/
www.linkedin.com/in/eharmoush/
What happens in your Discord?
@@adedejiemmanuel1 It's just a place for people learning networking to gather. I'm in there often enough if you also want to ask follow on questions.
I also use Discord for the student chat for students of my courses: classes.pracnet.net/
There are a lot of great networking tutorials on UA-cam but this series is by far the best. You explain everything so clearly and with great examples to help reinforce the knowledge. Thank you so much for taking the time to make these videos, they are absolutely fantastic.
Thank you for the kind words, Kiwi =) Glad you enjoyed it. Please help me spread the word about this content!
I agree with you Kiwi. This is a final destination for me
😁🤓AWESOME and THANK you!! The animation makes this like Saturday morning cartoons I love!😊
This course is one of the best tutorials I've seen. Thanks for all your effort.
Thank you, Pete. I appreciate the kind words.
Could you do me a favor? Do you mind sharing this video on Linked In, Reddit, Facebook, or any other social media you use? As an independent creator, that would be an _enormous_ help, and I would appreciate it _greatly_ .
Your genius at explaining something in such simplicity is out of this world.
Thank God very much for your existence.
Thanks again, CoolNerd =). Glad you're enjoying this series!
@@PracticalNetworking Of course!!! Thank you so much!
Criminal you're not doing the entire course. I'm entering back into university and this is such a flawless tutorial from top to bottom. I'd have no issue paying for the full course.
The full course will be completed. I'm 100% committed to it. Rest assured =)
Please do already! 😢❤@@PracticalNetworking
@@PracticalNetworkingwe really do appreciate you for committing to it! Great course 👍🏾
I am watching this again, like new wine, its evergreen. Thank you.
Hey Practical Networking.. I just wanna let you know, that lately I've been trying to learn about networking to help better understand a career I want to go in. I am so thankful that you are here to help us learn about this. I am understanding practically everything (with research here and there) easily and I'm becoming more comfortable pursuing this kind of career. This is as far as I am now, and I want to say thank you again for providing us with this information and illustration. I have a lot of patience, and I have been doing the same job for almost 13 years now with fast food and I've always been interested in computers and technology since I was a kid, even automotive which may have some common deployment since cars are becoming more and more electronic. This seems like a fascinating field and I will keep pursuing it.
Hi Onyx, thank you for taking the time to write out this comment. I am _thrilled_ that you are considering Networking as a career and I am honored that my videos have helped you in that journey. It is a very rewarding career with lots of opportunities, and I wish you all the best in finding them. Cheers, Onyx, and good luck!
@@PracticalNetworking You're welcome sire and thank ya!
You can absolutely do it! I used to work odd jobs, gas stations, grocery stores, etc. having no education. Then I became unemployed and was on welfare for a while. That was the point when I decided to do something different, and I started pursuing the IT carreer. I now work as an IT consultant, working very comfortably from home most of the time, earning a decent wage. If I could do that, I think anyone could.
Okay. I knew nothing about communications and how internet worked in general. Your tutorial playlist on networking is GOLD, and i seriously mean it !
Now, i can think of how i can architecture my network at home, how i can create my personnal server and how i can connect to it... Even from another location, through internet ;)
Thank you a LOT !!!
Whoa Nicolas, thanks for the kind note =). It's almost as of the intent of this series was to provide a *practical* explanation of *networking* . It's _almost_ as if that's the whole purpose of the channel ;)
In any case, glad you got a lot out of it. =)
the best ever to explain Networking Fundamentals period
The best networking courses I have ever seen so far!! Thank you very much!!!
By far one of the best series on Networking I can say. Whoever wants to know the basic and in detail concepts of networking can simply ignore other contents on you tube and just watch this one. It gives you all necessary knowledge with great examples.
Hey @PracticalNetworking,
Thank you so much for posting this tutorial and helping us in understanding the concepts in simple and best way. all content I was searching about networking in the past two days, I have got it in this series itself. I will definitely recommend this to others and share the videos as we.. Thanks once again for posting this kind of tutorials which are helping us a lot.
One of the most practical series and so easy to understand difficult subject. Please create the full fundamental course, I think whoever will watch it, definitely get benefit from it. Also, if you can have some lesson on i.e Network types on VM, i.e. NAT, Host only etc work & How Kubernetes and WAN technology works in basic , then I will be grateful to you. Thanks a lot
:)
Your lessons make esoteric material easy for the brain to absorb. Tahnk yuo!
Learn,flood and forward. i will never forget this about switches. Amazing explanation. I can not skip any of these videos .
Thank you, Kofi =)
This series is the best networking tutorial I have seen so far on the internet. Thanks for doing a great Job.
Please continue creating more networking videos. You explain it in such a way that I always understand by the end. The best out there for me. Would love to see you cover all the aspects. Thanks for spending the time to put these together for free!
Exellent😊
I'm "SWITCHING" my subscription and adding this channel. I'm "SWITCHING" my attitude about networking because this channel is 🔥💥💯.✌🏾😜
Love it =). Got a kick out of your comment. Glad you're enjoying this content, Harold.
You are the best.
Thanks again man. Clear, well structured, and to the point. Perfect for a newbie.
You're welcome, Antonio. Glad you enjoyed the content!
After finishing the playlist, I will be purchasing the Full Course to extend my gratitude to Ed. I'm sure the TLS Deep Dive won't be too far off too!
I really appreciate your lessons that you have created.
First of all I would like to thank you for posting such a great playlist on youtube for free. You are an amazing person.
I got a question relating to this video. At 2:06 you mentioned that we can get rid of IPs on this layer. Let say, I'm going to ping computer 1 from computer 2 and are both in the same network connected via a switch. How can I ping computer 2 then If there's no IP? we can't ping a device using its MAC Address.
You're very welcome, I'm thrilled you've enjoyed.
Here when I said we can "get rid of anything IP related", I meant only in the illustration. In the background, however, IP is still required for communication.
Remember in this video I was trying to remove all extra variables so we could focus purely on switches and what switches use to make forwarding decisions.
@PracticalNetworking I understand. Thank you for clarification.
Excellent! You're kind of a computer networking wizard, very good at explaining how it works. Thanks for sharing your knowledge.
You're very welcome, Jeytis. Cheers!
Does it flood ports that are already listed in the MAC address table? That seems unnecessary.
Really enjoying this series so far. Thank you.
Your videos are really great to understand networking flow. I am really happy that this channel exists
I've spent money on udemy to understand "nothing" (i mean i've learned the hard way with teachers explaining the "hard" and "complex" way" and i've found that u have the best wording to explain everything so easily and understandable. Its not easy to have this ability. >Thanks
Great work. I watched it one time. I need watch it at least 3 times.
Good stuff, I prefer this over my past professors in univ
This is another excellent, succinct tutorial from Practical Networking!
thank you very much man!!
love from Israel!
your course is very helpful.
Great Mentor !!Impressed by the way you teach. Please cover all switching and routing concepts with protocols
Routers are covered in the next few videos of the series =). Here's the full playlist: ua-cam.com/play/PLIFyRwBY_4bRLmKfP1KnZA6rZbRHtxmXi.html
Crystal clear explanations and definitions of everything here. I think it would be difficult to NOT understand the concepts after you've explained them. THANKS Ed! (:
Finally some deeper explanation, I was really interested in MACs part ,and still simple, thank you!
Glad you enjoyed it. You're welcome!
Amazing stuff. I just keep watching your videos from the time I discovered them.
Glad you like them!
whoever wrote the boring books on networking must not have a life at all.this explaisn WAAAAAYYYYY better then the books.
amazing clarity!
Thank you, Juan =)
A very succinct explanation of a complicated concept with great illustration. Deeply appreciate the effort taken.
Thank you for the kind words =). Hope you enjoy the rest of the videos in the series as well!
@@PracticalNetworking yes. I completed. I am not from a networking background and it was a great value addition for me. Your channel has been a Holy grail for me regarding networking. Many Thanks.
@@jaikishank I'm happy to hear my content has helped you in your journey. =).
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 / or amongst your peers? As an independent creator, that would be an _enormous_ help, and I would appreciate it _greatly_ .
Thanks for this video. It is very helpful. I don't have an IT or Network background, but it helps me to learn about networking fundamentals.
Awesome! That was the purpose of this series. Glad you enjoyed it =)
Preparing for an interview for second line (I know nothing about networking), this is a life saver 🥺
As usual outstanding explanation and wonderful teaching method...
Glad you enjoyed it, Ahsan.
Best of the best explanation
Thank you, Santhosh =).
This is amazing!!
You are a great teacher. Thanks for your explanations so simple to understand
This is fantastic! So simple and easily explained - thank you.
Thank you so much sir!
Awesome explanation for every subject!
Good explanation thank you
You are welcome
Waiting for remaining videos from same series. Great videos ! keep it up ... 👍
The next video in the series is available here:
ua-cam.com/video/G7GyWjJtjNs/v-deo.html
Otherwise, another project has come up that has to take priority over these videos. Regretably, the videos on Routers and Routing will have to be pushed back a few weeks.
Creating these videos takes significant time to design, record, and edit. I wouldn't want to rush the process at the possible cost of quality.
For what it's worth, the series is loosely based on an article series I wrote some years back. If you need the info sooner, a lot of it is available here:
www.practicalnetworking.net/series/packet-traveling/packet-traveling/
I like how the difference between talking thru the Switch vs speaking to the Switch to manage the LAN with SSH wss explained.
Glad you liked that part. It's a common place students get tripped up on so I wanted to call it out specifically. =)
PERFECT!!!
Very explicit! Thanks Sir.
superb brother even a 3 year old child can understand this nice
excellent narration
Absolutely brilliant
Thank you, mary.
ur a good teacher, thank you
Outstanding!!!! Your teaching style, awesome keep videos coming
Thanks Paul. Thank you for your support =)
Hi Great video. Except that I have some remarks.
Normally from what i can understand from the previous vids is that the process that you have described is related to ARP.
Basically when we want to initially send data from A to D, L3 and L2 are created. But in L2 we miss the DST Mac@. Hence, we send an ARP request. It is that ARP that is sent in a broadcast manner (Flooding), to resolve DST IP@. Host C and B will discard the frame and only D will respond unicast. Meanwhile MAC table of the switch is populated with both mapping of port 5 an 8 to A's and D's Mac@ respectively. The confusion is that, are you describing here the process of sending data after aqcuiring D's Mac@ through ARP, or are you describing the ARP process? Because again we cannot know mac@ of D but after doing the ARP (host started knowing this), and the flooding normalling is done in ARP process (we dont know yet D's Mac), so there is a confusion here.
If you were describing ARP process, then initially D's is unknown. and corrrect me if i'm wrong.
It is that if i understood well, if we know the mac@ of D, then the MAC table is already populated with all necessary information to carry out hop to hop delivery. Because we will already have used ARP
Thanks
You're on the right track.
Remember, the Switch's MAC table is completely independent from the Hosts' ARP table -- they do not share information and/or help each other.
The switch will flood if it doesn't know a particular MAC. The host will initiate ARP if it doesn't know a particular MAC.
More details on how it all fits together in the final video in the series: ua-cam.com/video/YJGGYKAV4pA/v-deo.html
(but I'd recommend not skipping lessons and watching all the videos in the series)
Good question.
@@PracticalNetworking Good answer. I think most "thinkers" will have this question. Good Answer.
@@watsonsmicrocomputers9297 Glad the answer helped.
As a teaching strategy, I opted to avoid talking about ARP when discussing switches, since a switch never initiates an ARP request. A switch only Learns/Floods/Forwards, depending on whatever packets show up. But, I can see how that would lead to this question being asked. Makes perfect sense.
@@PracticalNetworking I totally agree with your strategy. As a teacher, myself, I always (when effective) try to anticipate the questions of my best and worst students to briefly head them off, so they are not burning up bandwidth being stuck on that question. Questions that lower their processing power or inhibits it completely when talking about the rest of the information coming their way.
But most definitely, like you said, without removing the focus from the topic at hand.
excellent explanation
Well done, sir 👏
Thank you for supporting the channel =) I'm thrilled that you enjoy this lesson !
Perfect explanation with visuals. Thank you so much for investment of time on this.
One question here is acknowledgment of data received to a sender is happens automatically ?
Thank you!
Acknowledgement of Data only occurs in TCP at L4. So it's "external" to everything in this series.
@@PracticalNetworking okey thank you again
Great job
Exceptionally well explained !!!!! Thanks a ton ☺☺
One question, wouldn't the flooding be done as part of the ARP process? I.e if A already knows Ds mac address, it must have learned it via an ARP broadcast, in which case the frame would have been flooded out of all ports except the one it was received on.
So wouldn't the switch take that opportunity to build its mac address mapping for A and D so it doesn't have to redundantly flood the network at a later time? Is this example a scenario in which the switchs' port mapping table was lost/reset after an earlier ARP broadcast? I'm new to networking so I'm not sure of all the scenarios in which a switch will flood the LAN. Thank you!
Correct. I talk through that in the next video in the series =).
For this one, I wanted to start from the position of Host A already knowing Host D's to keep the Switch illustration as simple as possible.
@@PracticalNetworking thank you again, as some one new to networking your content is great
Glad you've liked it =).
If it isn't too much trouble, you probably know others that could benefit from understanding networking. Shares are greatly appreciated =)
You deserve an oscar award!! 👏 you
@PracticalNetworking, I have one doubt If you please clarify, A sent frame to D, which means that A has L2 information, having L2 information basically means that ARP has been already done. So in the process of ARP switch did Learn the MAC of A and D. So which basically implies that switch table does have information of A and D mac address. Which basically means flooding never occurs. Am I missing something? Please tell me
Around 2:20 in the video I explain we are skipping the arp process for the example to focus on only how the switch works.
There's an example in lesson 7 of the series which includes both arp and switch learning together.
Very good material
Thanks, Rafal
Perfect for newbie.
Thank you, Allan =)
Absolutely awsome sir,
Very clear explanation you got a new subscriber and follower ❤.
The video is very useful! very well done, thank you and keep it up.
Thank you. Will do =)
Unbelievable series!!! Amazing job. Where can I purchase the entire course?
More details here... still waiting to create entire course:
www.practicalnetworking.net/index/networking-fundamentals-how-data-moves-through-the-internet/
Great video!
Great video! thanks to share
Thanks a lot! But I was wondering just one little thing. You intentionally left ARP out of the equation in order to not repeat yourself what has already been said.
So if a sending host already knows the L2 details of a receiving host, ARP must have been performed before. So shouldn’t then the MAC Address Table of the switch already have ‘learned’ the connection details (port - MAC address) while ARP was performed in the first place?
Thanks!
So, yes... if the host had sent an ARP request, that would be enough to populate the MAC address. In my video I was skipping ARP entirely, as if the host some how, magically, already knew the MAC address it was trying to speak to (i.e., ARP never happened). Hope this clears it up.
@@PracticalNetworking Great, that’s all I wanted to know. Thanks…
Thank you for your work !
I can’t wait to jump into the subnetting mastery playlist …. I know u slam that shit!!!
If switch is configured to have an IP address, will it then be a Layer 3 device?
Becomes a router I guess
Thanks for the effort. Its great content.
Thank you for the video!
Very good video.
Amazing channel , thank you for this free course , does the access-point works the same way as the switch ?
Great explanation!!!
I just had a question. If switch knows about port 5 and port 8 and a frame is intended from port 8 to port 6 then will the switch flood the packet and send a copy of it to port 5 also? As it have entry of port 5 in mac table and knows its not the destination for the frame.
Great question. YES, the flooded frame will also go out port 5. The reason? Outside port 5 could be a host directly (as pictured) _or_ outside Port 5 could be another Switch, upon which Host 5 is residing.
It will make more sense in the next lesson when I show you how it works with multiple switches: ua-cam.com/video/G7GyWjJtjNs/v-deo.html
Man, these videos are great!
Glad you're enjoying them =)
Are switches built in these days to routers? I am trying to understand why we would need switches if a router (a TP link device for example) can implement this function within it.
Yes. A "switch" is a device who's primary purpose is "Switching". And "Switching" can be done by many difference divices.
Your home wifi router does both "Routing" and "Switching" (as the described in the respective videos)
Thank you very much
Thank you is just enough 🙏🙏🙏🙏
@@PracticalNetworking i am sorry .. I was about to put "Thank you is just not enough" .. typo 🙏 .. anyways .. continuing your lectures with full enthusiasm..
@@antonyrichard369 Glad to hear, Antony. I'm available for questions if needed =).
Very very good!
If you are not able to explain it to a six-year-old child, it means you don't understand it enough.
YOU ARE THE MASTER OF YOUR CRAFT
You could teach IT Network to a snail. For sure.
:) Thank you for the kind comment. Cheers, Natasha.
Great JOB! Right on POINT! Thanks a lot!
You're welcome!
Aren't the ARP request for the MAC address of Host D supposed to do that 'Learn' & 'Flood' part of the Switch? I know the demo is based on already knowing the MAC of Host D, but I'm curious about when it didn't.
Yes. Normally, the host's ARP resolution would be used for the switches' LEARN process.
For this demo I wanted to reduce variables so I left out ARP for the sake of creating an easier learning series =)
ang galing
Set speed to 0.75. Very smooth.
So if ports on the switch are swapped, during the "forward" action, does it also perform a verification that it's the correct MAC? And if it's not, then it starts over from the "learn" action?
When a port is disconnected, it triggers clearing the MAC address(es) associated with that port. So when they are "swapped", the MAC addresses table (for those ports) are empty, and yes, everything starts over with the Learn / Flood actions.
I have a few questions about a scenario:
6:14 - It’s assumed host D will send something back to A, and that’s when/how the switch will learn to populate the MAC table.
Is there a scenario where host A sent something to D, but did *not* need/want a response back?
If so, what would happen?
Would D simply get their data, and the switch would learn nothing?
Would D send information back to the switch so that the switch could populate the MAC table? Would the switch just not learn the information yet?
Great question.
Yes, there are scenarios where Host D does not send a response. That all comes down to the application being used. In the case of Ping, a response is expected. In the case of Syslog (for example), Host A is simply sending log events to Host D, and Host D is not confirming reception. Again, it all depends on what the application requires, so there could absolutely be a situation when Host D isn't expected to respond.
As for the rest of your questions... you are right, if Host D doesn't send anything, the Switch will never learn of it's MAC address.
In practice, however, almost every host when plugged into the network starts sending out probes to discover neighbors or "call home" (think, windows updates, or background weather apps, or clock syncs, or stuff like that). Most hosts these days are very "chatty", so almost immediately once they are connected the Switch will learn their MAC address.
I'll also mention... hosts typically also immediately send some Gratuitous ARPs when connecting to a network. This also will populate switch MAC tables. Details:
www.practicalnetworking.net/series/arp/gratuitous-arp/
@@PracticalNetworking Awesome. Terrific explanation, as are your videos. Much appreciated!
What if we change the arrangement of hosts in different ports, will the MAC addresses table be updated accordingly?
I am slightly confused. Previously, when covering communication within the same network you only mentioned L2 headers and the MAC address. So why all of a sudden do we need both the IP address and the MAC address for switches to facilitate communication between devices on the same network?
If you are talking about what is being discussed around the 0:50 mark, it's meant to mean that the HOSTS need to have both an IP address and a MAC to talk to each other, not that the IP address itself is used by the switch to facilitate communication.
In the end any host needs an IP address, as it needs to validate it to confirm that it was the intended recipient of the communication once the packet reaches level 3 of the ISO/OSI stack
Thank you for your videos, they are a great resource.
In this video we assumed Host A knows the MAC address of Host D. What if it didn’t? Is it possible for the switch to ‘Learn, Flood and Forward’ during the process when the ARP request/response is made?
Great question =). I answer it in the next video in the series =)
@@PracticalNetworking Thank you. I got the answer in the next video. 😊
Excellent! Glad you are enjoying this series =)
Thank you very much for these videos, which are more than wonderful.
I have a question about the switch.
does the MAC Address table start populating after the first broadcast, for instance, assuming an ARB request sent for the firs ttime from the computer A?
If yes, then why the switch is not start learning from the first broadcast of computer A.
Thanks again for this awesome contents.
Glad you enjoyed then. Yes, the MAC address tables starts populating from the first _anything_ that is received on the Switchport. In the example I used Unicast to keep it simple to teach Switching. But the final video in the Networking Series will outline what you are describing. Cheers =)
@@PracticalNetworking
thank you for replying.
Yes, I made it to the last video and noticed that.
@@mohanadmohamed5501 Excellent. Hope you enjoyed the series!
If you did, please consider sharing it among your peers =). THank you.
Thanks for this good video
You're welcome =)
Doubt: But why simple connecting the cable the Nic delivers the Mac Address or turning the host on? Or in the flooding other ports teach their appropriate Mac address?
The MAC address is part of the NIC itself. The Switch is learning what MAC address(es) exist on the _other_ side of the cable.
So in this case a hub is just flooding data right ?
The new feature of a switche is Learn &Forward -> via Mac adress table
Yup, exactly.
Blimey its getting complicated, thankyou
One step at a time, you'll get there =)