Multicast is just Weird.... Doesn't even know who gets it?

[@davidbombal]

Is this the strangest type of communication in networks or the Internet? The sender doesn't even know who is receiving the transmission. It could be a single device or thousands of devices. It just doesn't know - simply sends and forgets. The network needs to take care of things. // David's SOCIAL // Discord: discord.com/invite/usKSyzb Twitter: twitter.com/davidbombal Instagram: instagram.com/davidbombal LinkedIn: www.linkedin.com/in/davidbombal Facebook: facebook.com/davidbombal.co TikTok: tiktok.com/@davidbombal KZbin: kzbin.info // MY STUFF // www.amazon.com/shop/davidbombal // SPONSORS // Interested in sponsoring my videos? Reach out to my team here: [e-mail] // Menu // 00:00 - Intro 01:05 - Difference Between Multicast, Unicast & Broadcast 03:07 - Multicast 04:04 - Multicast Setup 04:47 - Address Classes 06:45 - Wireshark 10:23 - Multicasting and Broadcasting 14:27 - Demonstration 2 14:46 - IGMP Snooping 20:24 - How is the Typology Built? 30:50 - Conclusion 31:33 - Outro // Detailed Timestamps // 00:00:00 - Introduction to Data Streaming to Multiple Devices 00:00:06 - Explanation of Multicasting 00:00:12 - Devices Used in the Demonstration 00:00:17 - Multicast Stream Setup and Demonstration 00:00:28 - Definition and Use of Multicasting in Networking 00:00:46 - Examples of Multicasting Applications 00:01:10 - Unicast vs. Multicast Communication 00:01:41 - Multicast Streaming Process 00:02:04 - Differences Between Unicast, Multicast, and Broadcast 00:02:59 - Use of Address Resolution Protocol (ARP) in Networking 00:03:10 - Using VLC for Multicast Streaming 00:03:39 - VLC Multicast Streaming Setup 00:04:25 - UDP Protocol in Multicasting 00:05:26 - IP Address Ranges in Multicasting 00:06:02 - Setting Up Multicast Address in VLC 00:06:54 - Network Traffic Analysis with Wireshark 00:07:41 - Understanding MAC Addresses in Multicasting 00:09:13 - Importance of the Multicast Vendor Code 00:10:28 - Advantages of Multicasting Over Broadcasting 00:11:35 - Router Configuration for Multicasting 00:12:56 - Explanation of IGMP Snooping in Switches 00:14:31 - Detailed Multicast Network Topology 00:15:59 - Demonstration of Multicast Routing and IGMP Snooping 00:18:55 - Advanced Networking Concepts in Multicasting 00:20:25 - Building Multicast Distribution Trees 00:22:28 - Enabling Multicast Routing in Routers 00:23:23 - PIM Protocol in Multicast Routing 00:24:09 - Dynamic Multicast Routing Demonstration 00:26:24 - IGMP Join Messages in Multicast Subscriptions 00:27:36 - Impact of IGMP Snooping on Network Traffic 00:29:04 - Practical Implementation of Multicasting 00:31:04 - Summary and Future Topics in Networking vlc ip ipv4 ipv6 unicast multicast broadcast igmp igmp snooping

[@nkoecheler]

Awesome video! I've never heard of PIM, until today. Please continue going deep into protocols.

[@jackpetebourne5871]

I've found the MulticastDNSReponder, which is suspicious, on my Android phone. I can manage to disable/remove all other system packages except this one. Please help.

[@thewhitefalcon8539]

Trick question. This doesn't work on the Internet.

[@liamsoccerpro3040]

Whats the difrence between that and UDP

[@thewhitefalcon8539]

@@liamsoccerpro3040 Multi-cast. Leeloo Dallas Multi-cast. It casts multi.

[@ChrisGreer]

6:50 Yay Wireshark!! Nice job David! Great demo of how multicast works and how it looks at the protocol level. 👏👏

[@ebpsalm]

This is just sweet. So practical I love it. I recently got my CCNA and my friends were sure it's a waste of time because I was always playing in packet tracer but with this, I can flex a little even to non technical people. Thanks a lot David, I would like to watch more content where we apply networking to basic home devices and everyday used apps.

[@user-lg4le8xr4s]

As far as common device examples, consumer surveillance cameras and their apps tend to do a lot of multicast for discovery. Some cheap ones (Zosi for example) don't even obey your DHCP server, and just pick a random IP from the same subnet and then their app relies completely on their discovery method, using a multicasted device ID as identifier. Even if you try to give a camera like this a static IP it just does what it wants- it makes it a PITA to use cameras like this with Zoneminder etc or anything other than it's "official" app because it just keeps using random IPs. So you have to waste CPU cycles on your router doing igmp snooping to keep track of the thing. Or you can just put it on its own VLAN and feed it a /30 or something from dhcp so it doesn't have a big range of ips to jump around. I hate cameras like this

[@awex7]

congrats, trying to get mine. your friends have no idea how important your studying is, the world relies on networking and cyber security to go round. you’re now an important person. good luck on whatever you do next💪🏻

[@ray73864]

Multicast was awesome back in the Norton Ghost / FOG Project days, being able to reimage an entire lab of computers all at the exact same time, all initiated from your desk, all getting the exact same stream of data from the server. All finishing at pretty much the exact same time. And then along comes MDT and SCCM with its thin images utilising a WIM file, and, well, unicast is the most common deployment method for those.

[@romuloromero886]

This recording was very educational and informative. I would be interested in seeing more contents like these such as protocols and networking subject in general. I enjoy very much watching your videos, thank you for sharing.

[@SuperChoongus]

I have a bachelors in network engineering and my CCNA from '21, but have never gotten a good grasp on multicast. Although I knew mcast had its own dedicated IP class (range) I didn't really understand why or even realize that it was outside if any RFC 1918 addresses, so obviously hadn't fully considered all the applications of the technology. The single LAN implementation with different devices with a free app and packet caps was a fantastic introduction and really appreciate all the supplemental info!

[@scottspa74]

This was fantastic! I'd LOVE to see more like this (deep). Im currently studying for my CCNA (again), using your udemy course (and Jeremy's, and Neal's, and a few others), and ive never really seen multicast discussed in much depth at all. 👍🤘.

[@KrishanuKonar]

One of the best videos on multicast. Very clear explaination on the theory and the actual implementation of multicast. Subbed!

[@davidbombal]

Awesome, thank you!

[@JonLondrezos]

Some high-performance business apps use middleware, which in turn uses multicast for data transfers. How easy is it to a) intercept and capture messages, but more importantly b) inject "bad" multicast messages to corrupt data flows?

[@briancotten9245]

Loved this….i would be hard pressed to turn right around and relay this info to somebody else, but i understand the concept on this. GO DEEPER…MORE VIDEOS!! Lol. Videos like this are a great springboard for helping people understand things conceptually, but also gives them ideas on what other things they need study better in order to fully and deeply understand the concepts used. I hope that makes sense. Basically in this video i learned some new concepts and now know what specific things i need to further study in order to better solidify those concepts in my brain. Videos like this are a great resource! Even if I don’t 100% get everything, I get enough to know where i need to study more. Thanks!

[@Sipher69JD]

Great video! Appreciated the overview of PIM without getting too in the depths of the different modes. I would be interested on a BGP focused video, not sure if you've covered it in the past so my apologizes but given its importance to the internet it seems like a prime topic. Wasn't that huge "face-book" outage a while back caused by erroneous BGP updates? It would be neat to explore the types of vulnerabilities (and benefits) of BGP. Thanks again David, love the videos.

[@roaridse]

One thing you didn't mention; multicast on wireless have some issues as it has to be sent on a lower bitrate. Some access point deal with this by converting multicast to unicast packages , but not all . Multicast on wireless may also reduce battery life on batterypowered devices...

[@Abduselam.m]

Best channel that helps others how to success their education and work world

[@davidbombal]

Thank you! I appreciate that!

[@JaykPuten]

Interpretive dance is the strangest communication But.. via a computer.. fair point

[@davidbombal]

I was wondering what type of comments this video would get 😂 I am talking about networks, so glad you agree 😀

[@JaykPuten]

@@davidbombal lol glad I got mine in.. When we can trust webcams, I'm gonna set my slax machine to login and use interpretive dance for CLI inputs With a waving fist be a -h Actually if I had the time I'd put it on my pentest network using interpretive dance.. but I'm too lazy and don't drink more than like every fiscal quarter so I can't dance.. Plus I got more LoRa modules yesterday just asking to be put .8km/half mile away to just see what bandwidth I can push through Sorry this comment had the -v argument set

[@jonathantx]

Very interesting and exiting topic. This helps me understand multicasting more. Yes please create some more networking videos. Cyber security is great by without learning networking is like trying to run before you learn how to walk. Again awesome content.

[@harshvermac5IT]

Thankyou very much sir, We'd be glad if you continue these form of video and tell us more deeply about more strange things of networking.

[@BB-ik7mv]

Tnx David for the tip! The CCNA #1 exams there are to the end of every chapter kills me with this "multicastinga" questions. For this "multicating" questions because I am not a native english speaker I often have to translate the question for even to understand what on the earth the question wants to / from me. I do not understand a lot of thinks that the CCNA #1 want to learn us. But what to say? We as CCNA #1 students, have to comprehend (and digest) a lot of abstract concepts even before a practical basic and very simple setup could be put on running for us, a simple setup that can reveal at list 90% of that abstract concepts. Again 10x!

[@davidbombal]

So many people have shared the same frustration of having to translate English first... and then understanding the question. Best advice I heard was to spend extra time learning English: kzbin.info/www/bejne/fqGXkmOKlpaUldE

[@BB-ik7mv]

@@davidbombal Hello David! 10x 4 your reply! I appreciate your entire work! I sense a kind of unique and very professional implication in almost every post that I was able to watch from your cannel.

[@ZachB770]

Great video great example and even greater teacher ! Tnx a lot

[@francoisdewolfgiammattei9610]

I love your videos ! Yes, please go deep. For instance I would love to see traces done in an sdwan context and https sessions picking up and troubles with voip or other protocols. A 4G backup wan would be interesting as it would change more things when switching from a wan to the other. I did that a lot for customers and man it can be "very funny " sometimes and it's always teaching a lot. Thanks a lot for your great work !

[@buzooliibrahim8382]

I'm working in a cable Tv company we r internally using this technology. Such a wonderful explanation and thx David for it. Waiting for deep dive in this tech thx.

[@davidbombal]

Thank you!

[@Dgkateshiya]

thank you very much !!! cleared all the questions regarding multicast in just one video.

[@sorin.n]

Thank you! I learnt something new today. 👍

[@veerabsc]

I've been struggling with multicast, but your video explained it perfectly. Thanks for sharing your expertise - it's greatly appreciated!!! Can please we have more videos on multicast please 🙏🏽

[@1Yaron]

Thank you, very interesting, I'd love to see more network related topics covered.

[@aristotelisp3667]

This was very usefull and very well explained! Thank you!

[@nurseSean]

Thanks. That was relevant and digestible. It was a hearty meal but not too much.

[@Andreterragt]

This is incredibly useful!! I miss a CCNP course of yours!! That would be great! Thanks for amazing content!

[@ottoranks9227]

Hi David, just recently i had to deploy multicast streams into two networks shared over the same upstream vlan. Whats the best way to deploy to multiple networks separating the traffic / downstream vlan? So network 1 should not see mcast traffic on network 2 etc.

[@garanceadrosehn9691]

Very helpful video thanks to all the lower-level details. Thanks! I've always wished that big public events (such as major keynotes) could be sent via multicast instead of a million separate unicast connections. How much of a load would that put on the switches of major ISPs? If a company with a large network wanted to, could they have a computer which makes a standard unicast TCP/IP connection to some global video stream (such as a keynote), and then turn around and multicast that stream to the hosts on their internal network?

[@nournote]

Thanks for this well elaborated lesson.

[@JonMajorCCIE47884]

Can't wait to watch this later, multicast is one of my favorite technologies to support.

[@davidbombal]

I hope you enjoy the video. Hopefully all good for someone who is a CCIE 😀

[@JonMajorCCIE47884]

@@davidbombal Ha! I'm sure it will be, your content always is.

[@BoereplaasinthePhilippines]

ONE OF THE SMARTEST SOUTH AFRICAN GUYS I KNOW ON THE INTERNET, LOVE YOUR CONTENT, SIR

[@dastaan.]

Always informative and useful 👍

[@davidbombal]

Thank you! Glad you enjoyed the video :)

[@tonygibbs9339]

Thanks David. very interested. More on IGMP and PIM would be useful to me. 🙂

[@caiomotta8910]

A deep dive into MPLS would be exceptionally interesting! I am reviewing some of your older videos on it now.

[@evrgr33nz]

Hi David, Great video! I know in Healthcare multicast is used with patient monitoring systems sometimes across the WAN in several states. Can you cover Multicast troubleshooting as it relates to GLBP vs HSRP? I often hear of *,G (star comma G) but have no clue on what that means either.

[@mwangagary2265]

Yeah yeah great insight on networking.. Thank you for the video

[@juanmacias5922]

This is amazing, thanks for the breakdown of multicasting!

[@rtb1466]

Sir love the content. keep doing the good work. Go as deep that we can sink into the knowledge.

[@CraigHollabaugh]

Richard Stevens is smiling at your quick informative master class. I loved it, please continue detailed like this. Question, how can the clients determine the switch's mcast functionality other than just trying it? Thanks from Colorado.

[@davidbombal]

Thank you. That's a big compliment. They clients have no idea. They send an IGMP message to 224.0.0.1 for example. See RFC 2236 for more :)

[@CraigHollabaugh]

@@davidbombal will do, thanks.

[@telisijohn2054]

@davidbombal, How do routers on the internet re-transmit a multicast traffic to mitigate packet loss and time outs, and disconnects?

[@savke3268]

nice glasses frame you have there :D Which one they are? :D BTW, great job on yor videos!

[@marufavgonov4583]

The best cyber security channel ever 🙌

[@davidbombal]

Thank you!

[@BrannenTaylor]

Hi David - long time listener and evangelist of your channel. I’d love to see deeper, more technical content.

[@TheB1nary]

Routing protocol deep dives would be amazing!

[@muslim6460]

thank you David for this such great video , I didn't seen any video talk about multicast In detail , I hope see more topic like that , go to deep David

[@shaan129]

Thank you David ... i understand IGMP use on switch level which helps to stop overwhelming the bandwidth available but why IGMP snooping is required on R2 level

[@shaan129]

Also how does R2 know that R1 is the router to look for stream source ... Thank you for the video & would like to have in depth videos in Multicasting :)

[@davidbombal]

The router listens to IGMP messages to hear who has subscribed / left the multicast group to decide if it should forward the multicast to the segment or prune the multicast tree. The switch is snooping in on those IGMP messages.

[@garanceadrosehn9691]

I suspect multicast transmissions degrade more noticeably if packets are being dropped, since there is no way to retransmit packets?

[@Harryandsara]

Yeah , need to know about it even deeper...

[@chitlitlah]

I love learning about network protocols, but this seems like somewhat of a niche feature of the internet protocol. On a typical home network or small business network, there's only going to be a few nodes to begin with, so what are the odds one node will need to send to several but not all nodes? If the need does arrive, there's probably enough spare bandwidth to have a few unicast connections. On the internet or a really large network, it's going to be too complicated for routers to keep track of who is subscribed to each transmission and how to get the packets to the subscribers. That leaves medium-sized enterprise networks with a few routers and a few hundred or thousand nodes, but how often do you need one computer to send data to multiple computers without any kind of a response? I could probably come up with something, but it wouldn't be something common. Of course video conferences are going to have data going to and from each node, so that doesn't seem like a good use for it.

[@danieldewindt3919]

Grate explanation. Before it was like poking in a black box

[@virtualizeeverything]

this is a really cool demo thank you

[@prakashsharma7010]

When i am trying to multicast using VLC in mackbook, it's very slow streaming, its never in sync with original video. could it be network issue or I am missing something here?

[@BazShe]

i dont think the nic has enough computing power to drop a multicast stream. i think you are confused what a nic actually does. its up to the router or firewall to drop those packets. if your firewall is on your pc they will br dropped by the firewall application or kernel module on your pc.

[@bibi9984]

love your video well organize and explanation

[@mahdinasiri]

This is great, thank you

[@AsarMd]

I would suggest to make a whole course on CCIE with practical lab It would be a great effort form you to those who are struggling very much enthusiastic to see your videos on these topics

[@_roddypiper_]

This was great! Go deep BGP!

[@dakkodagankk6834]

Nice video. Keep doing the good work

[@Growler-F18]

Yes please, I studied Electronic ENG. TECH'GY, and studied the CCNA program and rx'ed my certificates for each segment completed...it would be nice get back into it and go back over how the PC's communicate via the O.S.I (7 LAYERS) ETC.

[@harshvermac5IT]

I'd love to learn about anycast in detail by you. Your explanation just shines 👌

[@trejrco]

Anycast is easy - "one to nearest of many" - kind of like an international supplicate address, often on separate devices / in separate places, relying on routing to just get the packets to the nearest instance. Anycast Default Gateway is one of the newest uses ...

[@harshvermac5IT]

@@trejrco the new address generation (IPv6) for anycast is the crux of confusion to me.

[@trejrco]

@@harshvermac5IT It isn't really anything special though - just suppresses duplicate address detection checks so they can be on same routed subnet ....

[@offItachiUchiha]

When i try to run "nh" command it shows like sudo: unable to get time of day: Value too large for defined data type sudo: error initializing audit plugin sudoers_audit How to solve this and my phone model is Samsung A13

[@outerkeentertainment7820]

Hi which video should I watch to know more about coding and other beginners staff

[@mohamadcisco5120]

Greate video, thanks David

[@slainiae]

Hi David. Is there a router that you would recommend that easily enables parental control of devices within the home?

[@SystemDemon]

We love you David 🎉🎉

[@sam_sheridan]

Great explanation

[@bibi9984]

yes show more multi casting ,routing protocols ,bgp

[@247DAVIES]

Love to be personally taught by you. I took that in, 100% 👍

[@Queron-vO]

Very interesting and good explanation. But what can this actually be used for?

[@newkoviak]

I have 2 pc’s, multiple cellphones, that i’ve found traces of multicasting. I suspect some hidden virtual machines that are embedded in places i cant access (maybe I just dont know how to handle it…) where they are obviously up to things hidden on ghost displays. Its been a very inconvenient exploit that has had damaging results in my real life offline. Any advice?

[@immny]

Hey mr ccie David this is advance topic today 😮 thanks

[@tetttettamilli6761]

@DB - "I'm thinking of going really deep, let me know what you think" Yes, absolutely - get into the nitty-gritty. Go granular (or go home). Thanks in advance.

[@davidbombal]

Thank you! Challenge accepted 😀

[@tetttettamilli6761]

​@@davidbombal- The idea of "node communication protocols" are all over the place. Of interest to me, in auto diagnostics, it's CAN, which,within itself, uses several protocols... Freaking fascinating.

[@Cyber_realm]

Thank you i wish ti look more from you dave

[@sailinn5288]

Haven't been watching david for a while. For only like over 6 months💀

[@davidbombal]

You can go and stand in the corner and say 1,000 times "I will watch David's video!" 😂

[@dustcore]

More networking please 💪🏾

[@mtnsolutions]

freakin sweeeeet..... thanks David

[@jbirdaspec]

Sometimes I like to mess with our network engineer and ask him about enabling multicast across multiple subnets 😈

[@NoRx141]

Best youtube channel 🖤

[@davidbombal]

Thank you very much!

[@alexanderdark]

this is a highly interesting subject! please continue!

[@camelotenglishtuition6394]

You mentioned ospf in a comment. Maybe im wrong, but isn't this just a protocol to see which path is faster for networking rather than the same "multicasting" implied by the video?

[@adityashinde1]

I wish I could learn everything from you in offline mode.

[@royalhooks3943]

Thank you David

[@davidbombal]

You're welcome!

[@Frostulv]

Bad example with google, I assume most are using udp/quic towards google.

[@cmbrlnd94]

CCIE series would be great!

[@ahmadmamo7517]

You are the best

[@davidbombal]

Thank you very much!

[@OleksandrSe]

David... You're just amazing. If you read it - just know that you're amazing 😌🥃

[@Siddh-f7o]

can you do the same thing with chrome os Flex?

[@immny]

Is mobile phones subscriber multicast by default or

[@kjakobsen]

It doesn't know, because it doesn't have to know.

[@RobvandenBoogaard]

Yes, go deep!! 🙌🏻

[@WmJamesWofford]

Dive! Dive! Dive!

[@davidbombal]

Thank you! I'll go deep 😀

[@WmJamesWofford]

xoxoxo = 42

[@diegomarche]

Loved this content, so useful for my job! Bring more of it, looking forward to the even more in depth analysis.

[@davidbombal]

Very happy to hear that! 😀

[@carsonjamesiv2512]

YES, PLEASE DO MORE VIDEOS, PROF.😀👍

[@hqxd7855]

What's thr name of the device that has Iphone connected to it in the video? I do not mean the brand, but an overall term.

[@seanchallenge]

Very interesting and would you do a video on Raspberry Pi multicast

[@hqxd7855]

Going deep into the networking protocols would be interesting for many of us. Will we represent a big chunk of your audience? It's hard to tell, though...

[@tonysolis6364]

Thank you! Youve done my job a lot easier now 😁

[@carsonjamesiv2512]

VERY INTERESTING😃😎

[@dellonbroadbell7519]

Interesting 💯

[@davidbombal]

Glad to hear that! I've gone a bit deeper in this video (especially the second half). I hope you learn something new 😀