The mere fact that you wrote back i truly appreciate so very much. You are a fantastic teacher. I am going for my ccnp route so these little tutorials are better than an entire cisco press book on the subject. You have a particular skillset and I hope it gives you tremendous success in the future.
Keith - is it just me, or is a crucial piece of this that in order for IGMP snooping to to work, the multicast router must be querying, or the switch must be set to be the querier. Snooping alone does not cause the traffic that the switch needs to snoop to be discovered - it's the querying that makes the snooping work.
Thank you for the request. I am working on a bunch of content for the new Cisco Certifications, but will add that to my list. Thank you for the request.
Late to the party. One thing to note is that IGMP Snooping is on by default with most switches (Dell, Brocade, Cisco). If you have an all Mac environment and are using Bonjour for web applications that interface with Airprint printers - turn this off. It took me a year before I realized that snooping absolutely wrecks bonjour/airprint connectivity on a wide scale. People had to wait around forever for the printers/scanners to populate on their web-app, if at all. IGMP disable for that network helped rectify the situation.
Question, so I’ve read up about IGMP snooping how great it is and all that. So far I’ve only found good stuff about it and can’t find any bad things about it when if I tried to google for it. So, why isn’t this feature on by default for all switches on all ports? What is holding it back?
Excellent video! For what particular reason you use or it needs to me used Multicast routing? And what about the querier. Didn't you have to configure one? I heard the querier IP should be configured for which subnet
Hello, this demostration is very interesting. Now my question is to know how i can have more security during multicast traffic? how i can know that one group is the rigth and the another group isn't? Maybe we need on the access point on authentification component? Thx for the support.
Thanks for the good explanation. May I ask you a question? I have a streamer running on my router OS embedded. The stream is coming over the udp to the multicast address. When I route the stream to my internal router interface (where PC is connected) VLC is successfully connecting and playing video. But I need to stream outside and when I rout the stream to the external interface I see the multicast traffic running (with tcpdump), but my VLC on my local PC doesn't connect anymore. My provider told me they have IGMP and PIM set and running. Unfortunately I cant check the stream as I have no other available PC. And the VLC on the smartphone doesn't support udp routing. What I misunderstood? What am I doing wrong?
Thank you Dkoxperia Koziukov. Feel free to join my Discord sever. Lots of people there helping each other out. Each Saturday at 10am Pacific I hold my "Office Hour" where learners can ask questions about the topics they are studying. Mostly focusing on Cisco CCNA 200-301 topics. Feel free to join us there live if you are available. Here is the link ogit.online/Join_OGIT_on_Discord Thanks again Dkoxperia Koziukov!
I have a question to see if you can solve it for me .. I have a manageable switch that has QoS, and within the QoS there is an option to give high, medium, low priority to ports .. on port 5 I have the router / ont connected which is the one that gives internet, and in port 1 the PlayStation 4 ... the question is: do I have to give high priority only to the console or also to the router that gives internet? And the igmp snooping is advisable to deactivate it to play or do I leave it activated? Thanks in advance and greetings
Thank you ElPelailla178. Feel free to join my Discord sever. Lots of people there helping each other out. Each Saturday at 10am Pacific I hold my "Office Hour" where learners can ask questions about the topics they are studying. Mostly focusing on Cisco CCNA 200-301 topics. Feel free to join us there live if you are available. Here is the link ogit.online/Join_OGIT_on_Discord Thanks again ElPelailla178!
Wow Keith, That was short and brilliant. I didn't have as easy of a time with DHCP snooping. I guess Multicast groups are easier to wrangle than the former. evan
Hi Keith, how does the switch know a pim router is connected, is it a mechanism built into igmp snooping & is it industry standard or vendor specific , thanks
Hi Keith, I created vlan for multicast and enable igmp snooping for that vlan. Currently I am getting nine stream from two different multicast address. One stream from 238.4.4.4, and eight stream from 239.0.0.1. I saw traffice from 1st address eliminated when I do not use it. But traffic from 2nd address always keeps coming in every port of my VLAN. Can you please tell me why this is happening? Thanks in advance.
im trying to get streamin from my cisco iptv box ISB2231.but i can`t get streams working yet.in my router from t-home with 4 lan ports just the lan port 3.and 4 are for iptv.can u help me.
It may not be licensed to be played on system other than the box itself. If there is any decryption required, that may also prevent it being played in VLC.
Keith Barker Thanks for the reply Keith. I did eventually understand at basic what it is and sorta how it works, but it took watching about half a dozen other people’s videos before I went ahhh, ok I got it. I do think you can update the video though on the very same topic and with updated information using your more up to date presentation format. Thanks though for accelerating my learning through your passion and passionate explanations.
The mere fact that you wrote back i truly appreciate so very much. You are a fantastic teacher. I am going for my ccnp route so these little tutorials are better than an entire cisco press book on the subject. You have a particular skillset and I hope it gives you tremendous success in the future.
been trying to look for good explain and this helps as well as demonstration, thanks Keith
OMG thank you! This is exactly what ive been looking for! A super simple straight forward explanation and example.
Thanks for great video. I finally understand what IGMP does and is used for.
Awesome video , short and explanatory.
As usual, Keith, you are the BEST!!!
Excellent explanation, easy to understand and to replicate.. Thanks..!
Thank you @davesradiorepairs6344!
love these old videos
Thank you Mr. Barker. I'm trying to do implement IGMP snooping in Some Small Business Switches.
Keith - is it just me, or is a crucial piece of this that in order for IGMP snooping to to work, the multicast router must be querying, or the switch must be set to be the querier. Snooping alone does not cause the traffic that the switch needs to snoop to be discovered - it's the querying that makes the snooping work.
That was a good video Keith thank you
Can you please update videos related to anycast in depth from start to finish
Thank you ☺️
Thank you for the request. I am working on a bunch of content for the new Cisco Certifications, but will add that to my list. Thank you for the request.
Very good, I tought it needed VLANs thanks!
You're welcome!
Late to the party. One thing to note is that IGMP Snooping is on by default with most switches (Dell, Brocade, Cisco). If you have an all Mac environment and are using Bonjour for web applications that interface with Airprint printers - turn this off. It took me a year before I realized that snooping absolutely wrecks bonjour/airprint connectivity on a wide scale. People had to wait around forever for the printers/scanners to populate on their web-app, if at all. IGMP disable for that network helped rectify the situation.
Question, so I’ve read up about IGMP snooping how great it is and all that. So far I’ve only found good stuff about it and can’t find any bad things about it when if I tried to google for it. So, why isn’t this feature on by default for all switches on all ports? What is holding it back?
Excellent video! For what particular reason you use or it needs to me used Multicast routing? And what about the querier. Didn't you have to configure one? I heard the querier IP should be configured for which subnet
Hello, this demostration is very interesting. Now my question is to know how i can have more security during multicast traffic? how i can know that one group is the rigth and the another group isn't? Maybe we need on the access point on authentification component? Thx for the support.
Once we had an issue when I was working at Sprint where the lec was doing igmp snooping and it broke multicast for our customer.
Thanks for the good explanation.
May I ask you a question?
I have a streamer running on my router OS embedded. The stream is coming over the udp to the multicast address.
When I route the stream to my internal router interface (where PC is connected) VLC is successfully connecting and playing video.
But I need to stream outside and when I rout the stream to the external interface I see the multicast traffic running (with tcpdump), but my VLC on my local PC doesn't connect anymore.
My provider told me they have IGMP and PIM set and running.
Unfortunately I cant check the stream as I have no other available PC. And the VLC on the smartphone doesn't support udp routing.
What I misunderstood? What am I doing wrong?
Thank you Dkoxperia Koziukov. Feel free to join my Discord sever. Lots of people there helping each other out. Each Saturday at 10am Pacific I hold my "Office Hour" where learners can ask questions about the topics they are studying. Mostly focusing on Cisco CCNA 200-301 topics. Feel free to join us there live if you are available. Here is the link ogit.online/Join_OGIT_on_Discord
Thanks again Dkoxperia Koziukov!
I have a question to see if you can solve it for me .. I have a manageable switch that has QoS, and within the QoS there is an option to give high, medium, low priority to ports .. on port 5 I have the router / ont connected which is the one that gives internet, and in port 1 the PlayStation 4 ... the question is: do I have to give high priority only to the console or also to the router that gives internet? And the igmp snooping is advisable to deactivate it to play or do I leave it activated? Thanks in advance and greetings
Thank you ElPelailla178. Feel free to join my Discord sever. Lots of people there helping each other out. Each Saturday at 10am Pacific I hold my "Office Hour" where learners can ask questions about the topics they are studying. Mostly focusing on Cisco CCNA 200-301 topics. Feel free to join us there live if you are available. Here is the link ogit.online/Join_OGIT_on_Discord
Thanks again ElPelailla178!
Wow Keith,
That was short and brilliant.
I didn't have as easy of a time with DHCP snooping. I guess Multicast groups are easier to wrangle than the former.
evan
Hi Keith, how does the switch know a pim router is connected, is it a mechanism built into igmp snooping & is it industry standard or vendor specific , thanks
Hi Keith,
I created vlan for multicast and enable igmp snooping for that vlan.
Currently I am getting nine stream from two different multicast address.
One stream from 238.4.4.4, and eight stream from 239.0.0.1. I saw
traffice from 1st address eliminated when I do not use it. But traffic
from 2nd address always keeps coming in every port of my VLAN. Can you
please tell me why this is happening?
Thanks in advance.
Will this mess up my DAHUA CCTV networks? i have 25 of them. and broadcasts is killing my network
Please make a multicasting tutorial. Your site 2 site vpn video is fantastic.
im trying to get streamin from my cisco iptv box ISB2231.but i can`t get streams working yet.in my router from t-home with 4 lan ports just the lan port 3.and 4 are for iptv.can u help me.
It may not be licensed to be played on system other than the box itself. If there is any decryption required, that may also prevent it being played in VLC.
i think it don`t have any encryption.sometimes it don`t give me any error msg.just the vlc stay in idle time
Wow, nice and clear!
Thank you @lpsmaduk!
Thanks Keith
Liked it.
Regards
BJ
gracias muy interesante.
Thank you!
Welcome!
I am still here in 2024
Funny how multicast works on any 224 address without ever touching a router or switch. What a hack
I don’t quite understand IGMP Snooping!
en.wikipedia.org/wiki/IGMP_snooping
Keith Barker Thanks for the reply Keith. I did eventually understand at basic what it is and sorta how it works, but it took watching about half a dozen other people’s videos before I went ahhh, ok I got it. I do think you can update the video though on the very same topic and with updated information using your more up to date presentation format. Thanks though for accelerating my learning through your passion and passionate explanations.
Do a Google search for "igmp snooping cisco" there are dozens of documents on the topic.