Linn Music Streamers and Meraki

[MrBear]

Good evening,

I just replaced my Cisco network with an all Meraki network.  I have a large number of Linn music streamers but things are not working correctly on Meraki.  If it matters, I have a MX100.

I found the following information from the manufacturer (Linn) but I do not know how to check Meraki's setting nor how to make any changes if needed... anyone care to help out a first week newb?

Services, ports, protocols:
The Services, ports and protocols are used by the Linn app and players in the network

UPnP & SSDP (Linn DS/DSM discovery and control)
Port 1900 (UDP)
Port 2869 (TCP),
Ports 49152-65535 (both TCP & UDP)

LPEC (Linn Products Event Control)
Port 23 (TCP)

mDNS (Bonjour)
IPV4 224.0.0.251 port 5353 (UDP)

DHCP
Ports 67, 68 (UDP)

ODP (OpenHome Device Protocol)
TCP on an ephemeral port

------------------------------------

A bit more on my network. In addition to the MX100, I also have several Meraki switches and about a dozen Meraki AP's.  

At this moment, I have everything on 192.168.1.x  (though this will likely change once we sort everything out.

All the Linn streamers connect via wired ethernet but all the devices that run the player software (Linn Kazoo) is WiFi.

The Linn streamers are "working" (sort of) right now... I cannot explain why, but it seems like depending on which Meraki AP I am connected to, will dictate which Linn Streamers I can see displayed in Kazoo (before Meraki, I could see all of them no matter where I was on property).

https://docs.linn.co.uk/wiki/index.php/Linn_DS/DSM_Network_requirements

[Maclanta]

Do these music streamers use multicast? I just went through a crash course in realtime with a Q-SYS music system where we had to remove UniFi switches and migrate to Meraki to make it work. That system had specific multicast requirements which were QoS on the switches and IGMP Snooping with a Querier. To do that you have to enable a Layer 3 interface on a switch. Without those two things Q-SYS won’t work. Anyway if any of that is necessary then the manufacturer should say so.

[Uberseehandel]

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@Maclanta wrote:

Do these music streamers use multicast?

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mDNS - multicast DNS. 

It gets tricksy. One can configure audio and video streaming services on L2 switches, using a router as the proxy / reflector. mDNS does work in the Meraki environment
 https://documentation.meraki.com/MX/Other_Topics/Configuring_Bonjour_forwarding_for_the_MX_Security_... 

Multicast IP TV is another matter, sadly, as is UPnP
https://documentation.meraki.com/MX/Other_Topics/Universal_Plug_and_Play_(UPnP)_support 

[Maclanta]

Multicast DNS or mDNS is a discovery service. That is not what I meant by multicast. I was referring to the system serving multicast streams out to players or transmitters serving multicast. So far I can't discern from the conversation what the issue is. The mDNS references suggest device discovery is the problem. But if multicast streaming is being utilized then that's a whole other thing. A packet capture can tell. The problem with improperly handled multicast is that internal multicast streams will flood all ports on all switches as broadcast storms if IGMP snooping and an IGMP querier are not properly configured. Such storms can cause devices simply to disappear, because their ports are slammed with broadcast storms. It does not take a high level of traffic to do this. And when this spills onto AP's it can be the same problem.

I noted this on a Linn board discussing the issue. Meraki can handle this, if this is the issue, I just has to be setup correctly: https://docs.linn.co.uk/wiki/index.php/Multicast_Filtering

[MrBear]

Hi Maclanta

I now see I didn't do a very good job of explaining "what" the problem is that I have.

Pre-Meraki:  When using the App (Linn Kazoo) and looking at the drop-down list of all the rooms that have the streamers located (there are 21 in total),  I would see all 21 rooms and can choose whichever room & play music in that room.

Post-Merak:  I am no longer seeing all 21 rooms (aka streamers) but only a small subset.  Then if I go to a different floor or area of the property, I will see a different small subset of rooms.  As a matter of fact, I was in a different area I have not been since the install and I saw ZERO rooms available.  So in my very limited experience, it kinda sound like a discovery issue maybe?

My limited understand of multicast in the Linn world, I "think" is when one optionally uses a feature called "Songcast" and that basically links which ever room(s) (or all rooms) that you select, to all play the same music, in perfect synchronization in all of the "selected" rooms.  An example of how to use this optional feature is:  You are having a large gathering of people, and you want the music to play & sound seamless when people flow from room to room to room.

Here is another copy/past of Linn info and then a link too, if you don't mind taking a read

Thank you 🙂

Managed Switches

Make sure they are programmed to work in Layer-2 mode

Jumbo packet/frames networking

This is not an official standard and is not supported by the Linn DS/DSM.

Multicast or Unicast

If you are using more than six Linn DS/DSM products in the same network and want to share/Songcast the music to other rooms then make sure the LAN can support Multicasting.

If you have issues with your Routers check:

• QoS is turned OFF (some Routers do not implement this consistantly and this may block Linn DS discovery).
• If you have a simple network with Unmanaged switches, turn "IGMP Snooping" - OFF otherwise check IGMPv2 and IGMPv3 is supported.
• On BTHomeHubs turn "Extended UPnP security" - OFF
• On DLINK, within "Advanced", Multicast Streams - ENABLE

https://docs.linn.co.uk/wiki/index.php/Multicast_Filtering

[Uberseehandel]

The Linn website is a classic. 😒

As far as I can tell, they are trying to sell these - i.e. avoiding the existing network. However, Linn streamers will function in a Crestron environment, for which I have some information from a group of installers trying to nut out how to shoehorn Crestron into an existing VLAN architecture with configurable L2 switches. Let us know if you want it.

[MrBear]

Thanks Uberseehandel

There were several replies I need to read further but yours caught my eye because I have both Linn and Crestron, so I would love to see what you have. Thanks!

[Uberseehandel]

I have extracted my notes into a Word file.

If you could PM me with a real email address, I'll send it off to you. These are notes, some are proprietary material (Cisco).

There are some "code-like" passages, which are there for the benefit of any Meraki support engineer faced with what may have to be done to get this to work.

I am optimistic that not much needs to be done, and that what does have to be done is configurable on a L2 switch. Configuring the MX to forward Bonjour packets should work, even if we can't get UPnP to function.

[rhbirkelund]

An MX will not forward multicast traffic upstream, og between VLANs. So if you're trying to subscribe to a multicast stream coming from the internet, you're gonna have a bad time. Take a look at this KB article.

[MrBear]

Hi everyone. Thanks for all your help thus far and I would like to provide a bit of an update on things I've tried and some additional info I found regarding resolving this issue on a Cisco Switch...

Today I went to Meraki Dashboard/Switch/Configure/Switch Settings and disabled IGMP Snooping.  Shortly thereafter, I finally could see all the music streamers (Linn DSM's) inside the music player app (Linn Kazoo). Bottom line is it worked but I did reset it to the Meraki default setting of "Enabled".

The reason I re-Enabled it again is because this is NOT what the manufacturer recommends, because the resulting Multicast traffic may cause the AP's to be overloaded.

So naturally I am concerned about the possible addition of large amounts of Multicast traffic by going this route as a "fix" to my problem (we are talking 20+ music streamers on the network).

Whilst disabling IGMP Snooping did allow me to see ALL the streamers like I should, I think disabling IGMP Snooping as a fix, will causes a new issue to arise, if I am using an optional feature within the streamer, called “Songcast”. What is Songcast??? Linn Songcast allows you to share the Music playing on one Linn DSM with other Linn DSM's on the same computer network.

One example of how I would use that feature is: We are having a large gathering of people, and we want the music to play & sound seamless when guests flow from room, to room, to room, to room, etc.

Whilst Songcasting, Linn DSM players generate significant amounts of Multicast traffic on the network. Many consumer grade network switches, including many all-in-one router/switch/WAP units will broadcast this Multicast traffic to ALL devices on the network, rather than just those which have requested it.

The Solution???
The network traffic must be filtered to ensure that Multicast traffic is not sent over the wireless network… This uses a process known as IGMP Snooping

I just found a Linn support document that shows what settings to use if you have a Cisco SG300 switch… so maybe I just need to emulate the settings shown for the Cisco SG300 onto Meraki? Could you please read the Cisco document I am attaching, and then tell me if you think emulating those setting onto Meraki is recommended?… if so, I may need some help finding things within Meraki and how to make necessary changes 😊

[Maclanta · Accepted solution]

In my adventures on another brand of music servers and UniFi switches, I also experienced odd behaviors when dealing with snooping. That items showed up when you turned snooping off is somewhat not surprising. Without a IGMP Querier, snooping is only half done and you get odd behaviors. An IGMP Querier works hand in hand with IGMP snooping to form a complete configuration.

My solution on the above troubles was to ditch our UniFi switches and get Meraki switches. I normally specify Meraki, but the customer had rejected them due to price. Big mistake by all. What I would recommend trying is the set up below, which is a fully set up network for multicast traffic.

So first reenable IGMP snooping. Second go to one of your Meraki switches and create a Layer 3 interface (Routing and DHCP). The chosen switch should be the one most central to the music streams. Preferably where the server is. Configure as the screen shot below using your subnet, not mine. Just choose an address on your existing VLAN subnet or on the VLAN subnet that has the music on it. Choose Enable IGMP Querier. The Querier works with Snooping to calm down the network and stop packets from going to ports that don't need them. Without it some multicast systems are just not going to work. You only want one Querier enabled switch on the subnet. Do not enable it on another switch or problems will arise.

My music system also required QoS on the switches to prevent pauses and drops. But I think the most important thing is getting the multicast snooping working right. It seemed Linn did not even suggest QoS according to the documents you shared.

If enabling a Querier does not work, then you can always undo it, but I think it's worth a try. Enabling that L3 interface is not going to turn your switch into a router. It will just be a L2 switch with an L3 interface that is only used for a Querier.

[MrBear]

That fixed it!!!!!!  Thank you so, so very much “Maclanta"... you went well above & beyond to help me 🙂

[Maclanta]

That’s awesome that it worked. The Linn documentation you shared gave me some doubts. I had a crash course on all this last month, and it’s good to know you did not have to go through the weeks of hell swapping out equipment like we did (UniFi to Meraki) to get it straightened out!