The Data Link Layer, MAC Addressing, and the Ethernet Frame

[BijouBakson]

This is probably the most detailed course on the subject that I have seen yet

[republicgreenfather]

Excellent Sir, I never seen such a wonderful Explanation with Best Presentation.Thank you Sir Great Job

[Hypocrisy.Allergic]

this is the course for the curious guys who really want to handle all the info, i love it, even though it s a bit too advanced, i find it challenging

[SixAstron]

Very well structured and presented. Thank you

[steveromanchuk]

I love it, the best explanation of the Data Link layer I've ever seen!

[zulauk]

Wow this is the best way I've ever heard this explained, thanks for such a well thought out video.

[iwktwom]

A uni exam tomorrow and this is fantastic, thanks for the brilliant content.

[mantid]

Going to watch all your videos. So detailed and I needed it badly!

[dannyuwu]

Great video! I used it to review for my networking exam. Keep it up!

[bernardgarrett]

I just want to add the 3 in 802.3 came from the fact that the guys from Digital Intel and Xerox were sitting at Table 3 of a restaurant (the Wagon Wheel) in San Jose, when they came up for the specification. The rest is history.

[petersu]

Bravo, excellent explanation of data link layer

[danielschiffers]

I love your video's! To the point, detailed and fun to watch.

[Benadamsonn]

Great and amazing explanation, well done danscourse

[dkmpala]

Thanks for the video, found it very easy to follow.

[zafranullah]

Very detailed and brilliantly explained.

[Charles-xdlw]

Excellent video. Thanks. I love your work.

[ninjahunter]

dd an exam u helped me nail it..thnk u

[James_Knott]

The preamble is used only on 10 Mb. On 100 Mb and faster, a different coding method is used and some reserved symbols are used to delimit the frames. Same with the inter-packet gap. Also, frames are no longer limited to 1500 bytes. That's an artifact of the original Ethernet and then by 802.3 using the Ethertype field for length. With DIX ll, it's Ethertype. Frame expansion appeared in the late 90s and now, with jumbo frames, 16K can be used, IIRC. You could have mentioned that if Ethertype/length is 1500 or less, it's an 803.2 frame and 1536 or greater for DIX ll. IP uses DIX and about the only thing that currently uses 802.3 is spanning tree. Other protocols that used to use it are now obsolete.

A good reference is Ethernet The Definitive Guide, from O'Reilly and, for a bit of history, you might want to download the Ethernet Blue Book (Gordon Bell), which goes into the original DIX protocol, before DIX ll & 802.3.

[robertolin]

Doesn't CD in CSMA/CD mean Collision Detection (instead of Collision Recovery shown in the first slide) ?

[potheeswaran]

Can you tell me why the destination address comes first in this ethernet frame? By default source address is first and then only the destination address. What is the logic behind this?