MicroNuggets: Broadcast Domains Explained

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In this video, Keith Barker covers BroadCast Domains: what they are at layer 2, how they interoperate with switches and hubs, and the common code name that’s used to refer to it on networks today. A cornerstone of this video is understanding the difference in how switches and hubs operate and how BroadCast Domains work with each piece of equipment.
Keith discusses BroadCast Domains and how it’s known by several different names. He’ll cover what a BroadCast Domain is at level two, how it interoperates with a switch or a hub, and then he’ll talk about the code name by which it’s commonly referred to on networks today. A switch memorizes layer two hardware addresses on each device; these are burned in from the factory, and the switch can take that information and make four ring decisions based on those layer two addresses. This is a smart approach to managing traffic, which is different from the “dumb” approach a hub uses. A switch can differentiate where traffic needs to go and only send those bits to the desired location, where a hub will send that information to every other port. A BroadCast Domain helps manage this.
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[@golamanik6582]

My life is now complete, this is SO easy and down to earth explanation, beautiful, I wish other IT videos in you tube were like this and made so much sense...

[@ae6112]

Probably one of the simplest explanations I've had of this concept...and the brief breakdown of Layer 1, 2 & 3 was great too

[@TheGodjilaye]

This is from far the BEST explanation i have seen about Broadcast domain !! Thanks, merci beaucoup !!!

[@fungukatanzania4829]

You are the best instructor so far.

[@Nj-kd4pv]

Great explanation.Thank you so much.

[@KeithBarker]

Hello Nadim- Thanks for the great question. One example when a L2 broadcast is used, is when computer A needs to learn it's default gateway's L2 (hardware MAC) address. It would use an ARP (address resolution protocol) message, which would be sent out to the L2 broadcast address of ff:ff:ff:ff:ff:ff (or all 1's in binary). Keith

[@cbtnuggets]

Thanks for the feedback!

[@KeithBarker]

Hi Jeff- Great question. Lots of Microsoft services, still use broadcasts (we would still see those). If we are running an older routing protocol such as RIP v1, it uses broadcasts. ARP caches entries that haven't been used in a while will time out, and then if a client needs to re-learn an ARP mapping, it will ARP again (which would be a broadcast again). Thanks for the question! Keith

[@euanta95]

really useful! I'm currently doing my HND in Networking and this has helped me to understand Broadcast domains!

[@adamidon146]

I'm new in studying networking and this video helps me a lot in understanding this topic. Thanks!

[@aumpatil6536]

loved this man, clearly explained. Thanks a lot!

[@adrianoos1977]

Your videos are great Keith!

[@Hikmatullah535]

Sir it was so interesting and I love the way you teach...

[@KeithBarker]

Thanks for the feedback! It is very much appreciated and I am glad to hear you enjoy this MicroNugget. -Keith

[@Meme-2m2e]

Thanks a lot, great simple clear explanation.

[@pratikbhandari5732]

Simply The BEST explanation!

[@fobup3up49394]

very good explaination thank you!

[@DesiStoics]

beautifully explained. Thanks heaps :)

[@neeradmittal9121]

Very nice and informative, now when it is usually said that the switch is intelligent and a hub is a dumb device, then for a 48 port switch working a default VLAN 1 , how or when does it really send the traffic by learning mac address of PCs connected to the ports thus not replicating to all the ports in the broadcast domain

[@reybars2961]

Thanks you thats so very helpful 👍👍👍

[@malaysiaboleh224]

u explained better than my lecturer did

[@l.m4631]

thank you very much

[@jdcafterbeef8130]

Hello Keith if the switch learn all the MAC address of all the computer and default gateway connected is there any broadcast happening or any type of broadcast after learning all the mac address of every devices to connected to the switch

[@lopezchris1987]

Awesome Video!

[@cbtnuggets]

Thank you Chris!

[@Hikmatullah535]

Sir what are the collision domain, half duplex and full duplex I'm really confused in these things?

[@ko95]

thx keith

[@ItsGosho]

VLAN = From one network create multiple independent networks

[@neeradmittal9121]

What else is an example of layer 2 address other than ff ff ff ff ff ff ?

[@abdulazizsameer8273]

big giant fat Like and subscribe , Thanks A lot man !!