A Packet's Journey - How Data Travels Across a Computer Network

[@azrics]

Omg! Im just about to give up searching this topic, finally! This is a very crystal clear and easy to understand explaination. U r da best!

[@karishmagummidi9300]

Very clear and easy to understand

[@RiyaKumari-ym3fr]

Great explanation, my seniors said this concept is important for job interviews , really helpful and simple explanation

[@AceNetworker]

Glad it was helpful! Thanks for watching!

[@themichaelw]

Thanks for putting this together. It was very well thought out. I think that simply noting the fact that the destination IP has to be resolved somehow (DNS) might be helpful. It's out of scope for the packet journey itself, but for very novice viewers, knowing that might be helpful.

[@markfung6418]

Love the clear and simple explanation for all your vids. Thank you for sharing!

[@AceNetworker]

You're welcome! Thanks for watching!

[@JoshHnatowych]

Thankyou thankyou thankyou! You rock!

[@AceNetworker]

You are so welcome! Thanks for watching!

[@amigazo3972]

Thanks a lot for the clear explanation. Totally for dummies like me :D It would have been nice to explain as well the handshakes process.

[@AceNetworker]

Great suggestion!

[@anantgaonkar941]

Simple & Clear !

[@AceNetworker]

Thank you! And thanks for watching!

[@MG7I]

I have a question. If the router sends the packet to another router? Would the first router still send the packet out with the pc mac address as the destination, or would it use the next routers mac address? due to it not knowing the pc mac address yet

[@AceNetworker]

This video may explain the process more clearly (hopefully)... kzbin.info/www/bejne/l3e1Yp6BgK-in8U But Source IP Address is the only thing that never changes (on most networks). So when a router receives a frame (w/ a packet inside) from another router, it sends it out its own port that best gets it to the Destination IP Address (again in the packet header). It encapsulates that packet into a NEW Frame with its own MAC address as Source MAC Address and the next hop/device MAC address as the Destination MAC Address in the Frame header.

[@MG7I]

@@AceNetworker so for example. If a router recives a packet with a mac address source of aa-aa-aa… and a destination of its own mac address, it then makes a new frame and changes the source mac to its own mac address and also changes the destination mac address to the mac address of the next hop (that the router finds to be the best path)(and that process repeats until it gets to the final router), and once it reaches the final router, the router makes the destination mac address, the address of the pc it was destined for and the source mac address its own mac address. But i have one last question. Does the destination ip ever change? I thought it didnt. But u just said the only thing that never changes is the source ip, when i thought both source and destination ip never change.

[@AceNetworker]

@@MG7I So yes, you are correct and I was incorrect. The Source and Destination IP's don't change. The Frames keep getting stripped off and rebuilt at each router or Layer 3 device. (Sorry for the confusion). The analogy I like to use with Frames are this: Think of each frame like a sled that is built just to carry that packet (with data) to the next device (MAC address). At each Layer 3 or Router, the old sled is stripped off and the packet is put into a new sled for the next journey to the next device.

[@MG7I]

@@AceNetworker ok makes sense, thank you very much

[@bard2227]

does the source mac address change when the packet is sent from the defualt gateway to 10.10.10.2?

[@AceNetworker]

@bard2227 It does indeed. The source IP address remains the same, but the source and destination MAC can (and often does) change between segments or from LAN to LAN

[@bard2227]

@@AceNetworker thank you sir

[@AceNetworker]

@bard2227 and (actually) I should have clarified that better: You'll usually keep the same Source MAC address within that LAN. Once you cross a Router (or other Layer 3 device) the Source MAC will change.

[@auriculares02]

So if a node would like to send data to another node outside of its network, the destination IP address will be the public IP address of that network since in your example, 10.10.10.2 is a private IP address. Is that right?

[@SophiaRosa2001]

Thank you!!! My lecturer has such a thick accent it's making it difficult to follow along. ❤

[@AceNetworker]

You're welcome. Thanks for watching! 😊

[@mohammadrafiq919]

Best Video But The Audio needs very minor improvement rest all crystal clear