IGMP Querier purpose in an IPTV setup

Getting noticed

IGMP Querier purpose in an IPTV setup



I have the following setup:


1 MS120-24P --> 1 MS220-8P

                       --> 1 MS220-8P


On the MS120-24P is an IPTV broadcast center (BCC)

On the MS220-8P are IPTV clients (smart TV and laptops with VLC)


All IPTV nodes are in a separate VLAN100

All IPTV nodes join VLAN 100 via access ports


On MS120-24P is an IGMP Querier configured

All switches have IGMP snooping enabled.



Now the issue:


The BCC sends about 300Mbps of multicast stream into vlan 100

If I look at my IPTV clients, I see 300Mbps of multicast going to these ports, even if these are not sending IGMP messages. In fact, there is no request for multicast streams whatsoever.

So why is the 300Mbps flooded?


The IGMP Querier is not really doing anything at the moment.


For the sake of clarification: the IGMP querier has an IP address in the vlan 100 subnet ( but the BCC has an IP address in subnet

I cannot change the BCC subnet right away (not under my management)

So what can be done to avoid the multivast flooding?


This is just a lab setup, but this will go eventually into production in large scale IPTV networks.



Kind of a big deal
Kind of a big deal

I thought the querier needed to be close to the sender (BCC in your case) in the same subnet, if you put it there does it work?

Kind of a big deal



I finally got it properly working.

changes I've made:

igmp querier and BCC server in same vlan and subnet, Although the latter is not really a hard requirement, but better to do anyhow.

More important and very obvious but easy to overlook, disable unknown multicast stream flooding on all switches. 🙂

Tracing shows, clients need to explicitly join the streams and block these when leaving/changing the stream.

it is all IGMPv3.


What I do lack is a proper overview of the clients joining particular streams.

Meraki is currently the only switch vendor not showing this.

I made a request to Meraki to have this incorporated in the Meraki features.


Thanks to all for your feedback

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