How does a computer communicate locally and remotely?

Secret of Subnet Mask:
• Secret of subnet mask
ARP:
• Address Resolution Pro...
In this video, I will talk about how a computer communicates locally and remotely once knowing the location of the destination computer. What different pieces of information and different networking devices will be used to communicate under these two different situations.
This is my education channel. My topics cover networking, security, programming, and other computer-related materials.
Please subscribe my channel. Many thanks.

[@gogamarra]

You're the man, Sunny. I've read so much material but in this video, the fog before my eyes has cleared.

[@eduardosegovia3752]

The best networking videos on KZbin, thanks a lot Sunny!!

[@lumiere2598]

I come here from Google's networking crash course and I have to say, I don't understand most of the stuff they say. You, on the other hand, makes things very clear in a matter of minutes. Thank you a lot!

[@ottodvalishvili7601]

Sunny is the god of networking.Very easily explained. I wish u millions of subs and views :)

[@sunnyclassroom24]

Thanks a lot.

[@jasonmyra6695]

Brilliant and simple explanation! Well done!

[@marceloaugustodossantos6355]

Sunny. Never be ashamed of your Chinglish. It's awsome and fully understandable. Greetings from Brazil !

[@xinong01]

Thank you, Sunny classroom, for your highly-spoken videos. I understand quite well subnet mask now and how computer communicates differently. I have a clear picture now due to you. I appreciate it very much. I salute to you!

[@beleakswordsteel]

You are the man. Been learning about this stuff for 6 months doing online classes now, and none of it explained subnet masks and what they do as clearly and easy to understand as you do. The animations help a lot.

[@sunnyclassroom24]

Glad it helped!

[@StealthyNomadica]

Double brilliant! Brilliance = the ability to represent complex concepts in an easy to understand format. Well done, Sunny!

[@sunnyclassroom24]

thank you very much!

[@davidvideauortega287]

Simply the best channel on computer networks out there. It's something like "Computer Network for dummies"! :)

[@sunnyclassroom24]

Glad you like them!

[@aubreyjarkey]

Your explanations are very clear and to the point, compared to so much of the over-complicated gobbledegook of other people attempts. Keep up the good work! Thank you.

[@walealex1613]

I had a class yesterday on ip address and subnetting. It was all foreign to me until I came across your videos. Thanks a lot sunny

[@fahada783]

Finally I find someone i can amazingly comprehend with easy explain

[@nefariousnilbog]

I cant belive how great you are at explaining these topics! Thanks a bunch, really looking forward to viewing every video of yours!

[@sunnyclassroom24]

Great to hear!

[@ibrahimwahab9801]

One of the best teacher ever seen explain all the modules clearly

[@6StringPsychedelic]

I really like this little guy, great presentation of all this information.. Helping me understand subnetting big time and I truly appreciate you Sunny! There are 4 hour videos that cant explain what you have so easily in a few short videos. Amazing

[@sunnyclassroom24]

Glad to help

[@limei5414]

You are the best teacher talking about internet!my confuse solved finally.

[@sunnyclassroom24]

Thank you very much! I am glad it helps you .

[@67rcampbell]

You do a great job to visually present the subject under instruction. I think you have been the best I've seen. Thanks for your efforts.

[@sunnyclassroom24]

Glad it was helpful!

[@gsmooffice3163]

It was a magnificent lecture! Very clear. Thank you.

[@richardacosta6047]

Simple and perfect, THANK YOU Sunny

[@ravinandanDB]

I subscribed this channel just to give a bow for his network knowledge and sharing his knowledge which he makes simple.

[@michaelrobinson9643]

Dont know if you still check comments Sunny - I want to express my thanks for your clear education. Far clearer than my Uni classes were at explaining a number of these concepts in a practical manner.

[@erased-ed2nl]

Sunny, very much appreciated!!! Thank you!!!! Very important, even critical topic. You are a tremendously talented educator and you are a tremendously skilled & competent IT-professional . Thank you!❤

[@ahemednor5201]

Thanks, it eliminates misunderstanding and make the picture more bright

[@sunnyclassroom24]

you are welcome. I am glad it helped.

[@jonlisec]

Thanks for taking the time to do this, very helpful!

[@sunnyclassroom24]

Glad it was helpful!

[@zhegal1]

Thank you Sunny for your great videos. Opened my mind. Please do put the links you refer to on the videos in the description box. Thank you

[@rongliao9255]

Clear concise tutorial! Thanks a lot!

[@sunnyclassroom24]

You're welcome!

[@yaz258]

Thanks a lot for the video! A lot of people over complicate it but these videos are easy to follow.

[@sunnyclassroom24]

Thanks a lot. I will try my best.

[@KB-dn9xu]

Absolutely the best videos on networking, simplified the complicated stuff👏. Keep going, good luck👍

[@arvindpal8070]

Thanks, Sunny sir to clear the concept in such an interesting manner.

[@tedros7629]

Thank You, Man! You always make things easier and better!

[@sunnyclassroom24]

Thank you for watching !

[@lefthookjake]

Sunny keep up the good I am liking your explanations very clear and concise. The examples you use make it very clear to understand.

[@sunnyclassroom24]

Thanks a lot for watching and leaving nice comment. I will do my best.

[@PinoyTechTutorials]

Thanks alot sir! very helpful illustrations and explanation.

[@4470rob]

Thank you Sunny.

[@addanametocontinue]

I've watched multiple video courses, including ones that cover CompTIA A+ and Network+ certifications and none of them cover why my computer needs to know the subnet mask it's locatedon. None of them ever state that it is my computer that determines whether it will send the data packet to a target MAC address or whether it sends it to the gateway and that's why it needs to know the subnet mask. My impression is that a lot of people who cover these topics don't really know the why behind it, they just know that's the way it is. Thanks for ironing out this mystery.

[@sunnyclassroom24]

I appreciate it! Thank you!

[@manojjohn5698]

Thank you for the amazing explanation :)

[@sunnyclassroom24]

You're very welcome!

[@TheMohbd73]

Thanks a lot, you are awesome. very nice video

[@hermessanhao]

This question is for both this video and the one right before it #34 "The Secret of the Subnet Mask" - How exactly would computer A check its IP address versus its subnet mask and computer B's (Or C's) IP address? I understand the logic of how computer A "knows" the B is local by comparing the IP address with the SM, but what is the exact mechanism that a computer will use to do this? Is it a protocol? By what process would a computer check the IP addresses with the subnet masks? Wonderful videos. Thank you, Professor Sun.

[@dongodilorica6037]

Thank you for your simple videos. I wish you more subscribers. 💪💪

[@sunnyclassroom24]

Thank you very much. I hope more subscribers too.

[@lifeslittleescapes]

Sunny's videos are addictive 😂😂😂

[@ahmedalzahrani7356]

Thank you Sunny. This is a great video and very useful.

[@stefanspanic1911]

Thank you Sunny! Very good video.

[@seenivasanramasamy4627]

Your way of teaching is beautiful

[@sunnyclassroom24]

Thanks a lot for your nice comment.

[@surgingcircuits6955]

Excellent.

[@lies4212]

you are such a great teacher!

[@sunnyclassroom24]

Thank you! 😃

[@raymondwiggins7806]

Very helpful video’s, thank you

[@user-fb9yd8wo8j]

Thank you sunny, very good explanation.

[@sunnyclassroom24]

You're most welcome!

[@ahmednihal5411]

Thank you sir appreciate it

[@asoteico9528]

Well done Sunny...!!!

[@anant8884]

Amazing man ..

[@ChitChat]

I work where the ISP uses quite a bit of /32 and always wondered why they use that and why not use /32 for everything if that's the case. I assumed everything got routed anyways, but yet again I underestimated the power of ARP.

[@mshaykhnet9831]

thank u very much

[@kjd7351]

Thank you.

[@sunnyclassroom24]

You are welcome!

[@chichilopez6409]

Sunny hope you're fine, I have a question... At the end of this video you said "ARP is used for both situations" you meant for local and external communications? ARP goes out the network from gateway to gateway til get the Mac of the ip given? Hope you can answer my question.

[@manipal2011]

For sending packets to Destination -> MAC address is used

[@dayumnson9769]

Hey Sunny does that mean that cummincation inside the same local network is faster than remote communication? (Ignoring travel times etc..) Just based on the fact, that we can use layer 2 communication instead of ip packets? Or does the "final" default gateway or router when sending our ip packet out in to open also unpack it and then use layer 2 communication? If it's a nat router it probably will? Or does the nat router also send the ip package to the natted private ip?

[@joshuadelacruz3907]

This is very ARPful

[@captainprototype187]

Sunny is a good teacher. I notice that he has an old class A ip address that starts with 10. Why is that?

[@manipal2011]

Function of ARP(IP address) returns (MAC address)

[@asuim9255]

Thank you.Your videos are simple to understand.I have one question and i really hope you will reply. When computer A communicates with computer C , computer A asks for default gateway's MAC address and after receiving it computer A sends its IP packets to the default gateway.You are saying that then default gateway sends this message to computer C.But how does the default gateway know to which computer on the internet(or somewhere) it should send this message?I mean how does the default gateway know computer C's IP address.Does the default gateway use ARP to know computer C's IP address?

[@dayumnson9769]

Good point. I assume you are correct on this. I assume the default gateway uses arp and ip until one default gateway is in the same subnet and then unpacks it and sends the rest of the traffic via the mac address.

[@SHAYOEDWARD]

Thanks alot sunny. But I want to know about class A to find out subnet mask, and new networking ID

[@sheereenhamza3700]

Will the steps be the same if my LAN is a wireless n/w? As in my Laptops and mobile phones connected wirelessly to router, and PC wired to router. (My router is a comb of router and switch).

[@abukarimu1595]

A very good tuition sir, but please I want to know how to install network?

[@bryancooper1079]

Dear Sir, can i assume the default gateway is a Router? Or it can be anything, such as; switch or router?

[@elielmurmu]

Firstly thank you for your great videos! Secondly I don't see subnet mask is being used to find whether a computer is local or remote. Because a computer use ARP to find the mac address of the other computer then the computer sends the information to communicate. If a local computer has the mac address then it just tells the first computer or the gateway device (router) tells that I have the mac address. Please explain if I am wrong.

[@deerlow1851]

It uses subnet mask to determine whether the other computer is on its local network. If it is, then it uses ARP to fetch the other computer's MAC address. If the subnet mask determines that the other computer is on a remote network, it does not fetch the MAC using ARP, it fetches the IP of the other computer instead. Let me know if this helped.

[@ewawaszczuk3829]

Does a local packet that goes to the computer in the same network, uses all the headings of the OSI model?

[@tsunghan_yu]

So the steps of A → C is: 1. A checks with subnet mask that C's IP is remote, so it needs to send it via default gateway. 2. Since it doesn't know default gateway's MAC address, it asks via ARP and gets it afterward. 3. send IP packets to default gateway and then to C Question: why step 2 is required? It seems that remote communication is so common, why not just store it in computer A and B?

[@benjaminp.skinner2543]

My guess would be that it is because the ARP entry is dynamic (meaning it is only kept on the computer for a short period of time after it is initially resolved and listed in the cache). When you check your ARP cache list in command prompt you'll notice the default gateway is listed as a dynamic entry. In the real world, like you said, since remote communication happens all the time when using the internet, the default gateway's MAC address would be continually refreshed and wouldn't expire, so the computer would probably never need to send an ARP request to resolve the MAC address of the default gateway, again, because it is being used so much. I believe Sunny's example was more a logical step by step process of a fresh new LAN rather than your typical home network which has already been running for a while. Why is the default gateway ARP entry dynamic? I'm not entirely sure, I assume it's to prevent any problems that might occur when connected to different networks with your computer or installing a different default gateway (with a different MAC address). You still have the option to manually add a static ARP entry (that does not expire) within the command prompt.

[@nonegiven]

@@benjaminp.skinner2543 That is correct. The MAC address is stored in computer A's arp cache, but only once the arp command has been sent and a reply received, so step 2 isn't always required if it already knows the MAC address from a previous arp. It is dynamic because it can change. If you change routers or pc's then you receive a new MAC address for that new router or machine. If pc A had been told a statically assigned MAC address referring to the old router then you wouldn't be able to reach the new router as the pc would still be trying to send to the old MAC address in its arp cache, as it was there already, it wouldn't have needed to broadcast an arp request.

[@manipal2011]

Subnet Mask will answer Question for Current Machine (is the Destination machine on Same network or Remote network)

[@anikuttanlucky9635]

Hi Sunny - you mentioned in one of the slide that MAC address is used for local comms and ip address is used for remote comms but that is not correct all communication between computers and devices use MAC address whether its LAN or WAN it uses ARP to resolve IP to MAC and MAC is used for remote communications as well.Internet is considered as one big LAN. This is what I understand

[@sunnyclassroom24]

For local communications, we only need MAC even though every computer has IP address.

[@jinsakjoy9707]

Can you make a vedio on how vehicles communicate using ip address and mac address

[@TheLunarGod]

I un-subbed from the other IT chanels chanels because this guy is that good on teaching.

[@sunnyclassroom24]

Thanks a lot for your encouragement.

[@navneet5060]

But what makes difference to know receiver is on local network or diffrenent network ???

[@AzmiBesar]

ARP is used to get MAC from the IP address of that host. But in 1st place how is the ip of that host is known ?

[@gautamgoel0505]

If computer A and Computer B are of different subnet mask. Will they able to communicate?

[@pging8328]

5:23 you state: subnet mask will answer the question: "is it on the same network or on a different network"...............why is this important to determine - I'm not understanding that bit? (Also, thx for the videos)

[@deerlow1851]

Because computers sharing a local network communicate with each other by MAC Address. Computers communicating from remote networks (over the internet, or any TCP/IP Protocol) are going to communicate using IP address to determine where packets are coming from and where they land.

[@voiceofreason314]

So ultimately, does computer A deliver the packets to computer C using MAC or IP?

[@deerlow1851]

IP

[@deerlow1851]

It delivers packets to Default Gateway using MAC and Default Gateway sends the packets with IP. Computer C never sees the MAC

[@jibnathgautamhy1280]

I don't understand why DHCP is in another network

[@heinrichruv2136]

Linux ==> ifconfig -a

[@GTACRaft85]

Really not helpfull