Crestron DM-NVX Issues, will IGMP querier resolve issues?

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Crestron DM-NVX Issues, will IGMP querier resolve issues?

Hey Community,


I need some help getting the Crestron DM-NVX to work. I know others have figured this out and I will link to other posts I have found.


MX100 -> VLAN 2017 Trunk -> MS225


From the MS225:

Port 3 = Crestron Server

Port 48 = Down stream switch with other AV devices


Current issue: Down stream devices on port 48 called NVX devices (they are Audio/video decoders) naturally do a lot of Multicast traffic. When those devices are online, it floods the VLAN 2017 and we get 99% packet loss on port 3 Crestron server.


We had this working fine for the last year, and recently installed MX100's in HA, which required us to reboot things, and since then this issue started.


It sounds like I need a layer 3 interface on the MS225 switch, specifically to enable IGMP snooping querier. Does anyone have info on how this would need to be setup? Do I just enter my info for VLAN 2017 in the image below, or is there more than that?





Links I have found:

1. This is why I was thinking I need to enable IGMP snooping querier: dm_nvx_network_min_requirements (

2. This talks more about this: Solved: Multicast Basic's - The Meraki Community

3. Found this article specifically about Creston/Meraki issues from a year ago: Crestron DM-NVX Video Distribution - The Meraki Community





5 Replies 5
Kind of a big deal
Kind of a big deal

The MS225 is not a full L3 switch so it will not do PIM but I think it can play igmp querier.  When you have an igmp querier on your subnet multicasts will only be sent to the ports that have multicast listeners for that specific stream.


The IGMP querier function is just an on/off switch and needs to be enabled on the VLANs that need multicast.  However it will not route multicast streams between subnets (for that you need a higher end switch).  So in your case if the multicast source and listeners are on the same subnet just enabling querier should be enough.

Kind of a big deal
Kind of a big deal

You are onto it.  Yes, just fill out that info and give the MS225 an IP address in the subnet being used for multicast.

Kind of a big deal
Kind of a big deal

If this only happened after a power cycle, you could consider giving the switch another power cycle in case it has got stuck in a bad state.


I would also check out the firmware release notes around multicast in case a newer release of the software has some improvements.

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I really hope this saves everyone a bunch of time....

MX 100 -> AV SWITCH 01 -> AV Network Stack


Basically when we put the Meraki's in HA it pulled traffic from the AV Network Stack switches over to the AV Switch 01. However the VRRP heartbeat packets work, it somehow is pulling that traffic to the rest of the network that it otherwise would not ever go.


I confirmed this happened on two networks. I removed HA from both networks and the issue is now gone.

Does this happen before you created the IGMP querier on the switch or after?
If you have not yet created the querier all your multicast traffic will be flooded to all ports on your MS225 including where the MX'es are at.  Or maybe not in some strange Meraki type behavior unless the MX'es start doing some multicast of their own and then those ports receive all video traffic too.

Also could you verify you don't have the same multicast mac addresses in your NVX video traffic that collides with the MAC addresses used for VRRP?

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