Requesting Updated Ethernet over Coax "working" list

Userlevel 2
Good Day All,

My client has 3 Sonos Bridges in his house. Due to long distances between SonosA and SonosB and C, we decided to wire SonosA and SonosB and let SonosC connect wirelessly to SonosB (Got all that?? :)

He is reluctant to run an ethernet cable to the other side of the house were SonosB and C live so it was decided that an "Ethernet over Coax" be deployed. Everybody was happy, birds were singing, unicorns dancing, etc. it doesn't. What changed you ask? Well I swapped out the entire network for a more consumer friendly network of Airport Extreme's, expresses, etc. That whole system works perfectly, except for the Sonos...

There is an GefenTV Ethernet over Coax sender and receiver to the other side of the house were SonosB and C live. SonosB should be hardwired but can't because a broadcast storm happens the second I plug it in the GefenTV EoC. I unplug it, internet works again. Most people who are reading this know that story.

So now you are probably thinking "Why doesn't he just swap out the new network for the one that was working?"...and you would be right on that except...that doesn't work either anymore. Nothing changed on the side of the EoC that SonosB lives on but for some reason it just causes broadcast storms every time I plug it in.

So after long sessions with Sonos support (really helpful btw thanks) and GefenTV as well as lugging SonosB to the other side of the house to test the switch(worked great btw), I realize that it has to be the Ethernet over Coax.

Sorry had to include some sort of backstory so it all makes sense.

Here is my question: I have no choice but to use Ethernet over Coax in my setup of SonosB and C on the other side of the house....Does anyone know of any of those devices that positively works with Sonos?????? Please don't make me beg :)

ps - i know Sonos doesn't officially support it but someone somewhere out there has to be using this to connect.

Thanks in advance everyone and have a good weekend.

15 replies

Welcome to the forum.

The fact that neither EoC system functions anymore leads me to believe another component is at fault here.

AFAIK, the Extreme is Spanning-Tree capable, so it shouldn't be the problem. You mention installing multiple Apple networking devices. Only one of them would be the router (presumably the Extreme), the others must be configured as a wireless access point or bridge. Is that how they're configured? When you mention swapping the new back to old, do you mean just the EoC, or the whole enchilada?

A more detailed connection mapping would be helpful too.
Userlevel 2
Has Gefen ever made anything that worked properly?

I've never used the gefen coax Ethernet extender, I had such a bad taste in my mouth from the HDMI and USB extenders I swore them off. I used a Startech sometime ago but it was in a non sonos application. Sorry I can't be of more assistance.
Userlevel 2
I use Netgear's product... MCA 1001 with no problems. I have several devices around my house...including my "master" Sonos device hard wired to my network this way.

However I tend to agree with NoBoB that the issue likely resides somewhere else.
Userlevel 2
Thank you everyone for your responses...

NoBoB - It's basically two sides of a house connected by ethernet over coax. i actually have two extremes but you are right there can be only one router. It goes like this I'll call it East for one side of the house and West for the other side...

East - Apple Extreme Router with a netgear switch. an ethernet cable was run to the upstairs where another switch was setup and hardwired airport express was put as an access point. An Ethernet cable was run to the kitchen on that side where a Sonos Connect is installed with no problems. Right next to the router is also where the GefenTV "sender" module is.

West - The GefenTV "receiver" is setup here. There is a built in 4 port switch on the receiver that has an airport extreme in AP mode. This is the point when I try to plug in a Sonos Connect it does a broadcast storm and we lose connection to the internet on that side of the house.

What I have done to troubleshoot..
Phew the list is endless but basically this past friday I took the West Sonos and wired it directly into netgear switch that i stated in the East part of the house and their was no broadcast storm. That eliminates the entire East portion of the house as the problem. The only thing I can think of is that it has to be the GefenTV EoC's built in switch. One more tidbit, after finally getting through to their tech support I found a check box that enabled multicast...problem fixed??? nope it brought down the entire west of the house just like a broadcast storm...defective device?? nope just bought a new one and the exact same problem.
The only thing i can think of is that there must have been an update run on the sonos which made it not be compatible with the GefenTV. Even if I put the old system back in and set it up exactly the same way it still doesn't work.
Honestly I can't remember the last time I was this frustrated with a product. Oh and to answer a potential question of why doesn't he just run an ethernet cable to the other side of house?? He has no desire to rip up the walls of the his house so it is EoC or nothing.

jdefuria650 - Have you tried hard wiring two connects, one on either side of the Netgear EoC?? Please say yes....

Thanks again everyone and have a great day!!
The only thing I can think of is that it has to be the GefenTV EoC's built in switch. One more tidbit, after finally getting through to their tech support I found a check box that enabled multicast...problem fixed??? nope it brought down the entire west of the house just like a broadcast storm...defective device?? nope just bought a new one and the exact same problem.
This sounds like a classic network loop problem.

Call GefenTV's tech support and ask them about Spanning Tree Protocol (STP) support in the EoC switch. It needs to either actively participate in STP ('STP-enabled') or passively forward the STP traffic ('BPDU flooding').

If it does neither -- i.e. it blocks the BPDUs -- then a loop will go undetected and a storm will result.
Userlevel 2
Thanks Ratty but I give up on the GefenTV device and was just looking for a replacement that people know works...
There's no Sonos update to be blamed here. If there was, no system with more than one wired unit would be functional, as they all depend on STP support to prevent the broadcast storm you're experiencing. If mine works, they all should (or if not, at least, Sonos in and of itself is not to blame). So get the 'Sonos update' out of your head, it will just cloud your troubleshooting thought processes.

I'm thinking I may have read more into the first post than there actually was. When you said 'swapped out the entire network' did that include the EoC? Your followup responses lead me to think the GefenTV has always been there. If that GefenTV device worked at one time, it still should. The only thing different is the rest of the network. It's Occam's Razor. If you change the network, and the EoC quits working, the problem is not a Sonos update.

Do you still get the storm if the East Extreme is not powered?

I think I'd bring all the components -- including the EoC -- to the West router location, and add and remove to see what breaks what.
Userlevel 2
NoBoB you didn't read what I wrote. It worked fine everywhere else Except for when i plugged it into the built in GefenTV switch which led me to believe it was the switch attached to the receiver in the west location. It has nothing to do with every component in the East because I took the whole system and moved it to the East location. As soon as i tried to plug the second Sonos into the west again it broadcast stormed. I know that the update worked otherwise they wouldn't have released it, all i'm saying is that it may have broken functionality with that particular Gefen EoC device.

Regardless of whether or not it works on one side or another, i still have to get it working via EoC and it does not with the current GefenTV device so that is why I am asking if anyone has a proven device that works.

Thank you everyone for you help but I just need a proven EoC device....
Has the GefenTV always been the EoC unit?
Userlevel 2
yes it has
yes it has

Then something else is wrong. If it worked once, it still should. We're missing something.

I'm going to have a hard time recommending a replacement model of EoC. The one you have *should* work, so it's hard to know if another won't just suffer the same fate 😞
Userlevel 2

jdefuria650 - Have you tried hard wiring two connects, one on either side of the Netgear EoC?? Please say yes....

Not sure what you mean by that, or how Geffen's implementation works. I'll try and explain how the Netgear system works. There is only a single type of hardware, the MCA 1001. There is no differentiation between "sender" and "receiver" hardware type though you of course need at least two units on your network to be effective.

One unit basically sits between the incoming cable internet coax feed (from the street) and your cable modem. I'll call this unit the "master". Once this unit is in place, all coax outlets in the house are now "Ethernet aware" so to speak.

Now that all the coax outlets in the house are ethernet aware, you can plug additional MCA 1001 units in at any coax outlet, and that provides an ethernet port.

In my house, I have one MCA 1001 unit set up at the cable modem (the "master" if you will). I have several other MCA 1001 units throughout the house where I want a hard-wire connection to my network. (Desktop PC, xbox, Blu-ray player...) One of these connections is my "master" Sonos unit (a Zp-90). This is the only Sonos component I have that happens to be wired.

Note, that the MCA1001 does NOT include an ethernet switch. (It sounds like your geffen unit might?) So if it is the switching aspect of your unit that is causing problems with spanning tree, the Netgear device might solve your problem (though you may have to buy a separate switch if needed.)

Also note that MoCA standard devices (including the Netgear) are not designed to work with satellite coax, only Cable. (MoCA devices are designed to operate the network in bands that do not affect cable TV signals, bands used by satellite operators are different, apparently). Finally, I don't know if you are in the U.S. or not...or if that makes a difference with MoCA devices.

Good luck!
Userlevel 2
Thanks jdefuria650 for the info, you just saved me a purchase. I was getting ready to try this out but for some reason it doesn't support DirectTV. I am in the US btw.

The Geffen unit has a built in switch which is probably the cause for the broadcast storm.

back to the drawing board....thanks again everyone.
Userlevel 2
ok i might have a winner....the star tech EOC110K..i will let everyone know...

question i have to get a switch now for it. Can you tell me a 4 port switch that works with Sonos? I know I know everything that isn't on the list published on their website...but this has been such a big issue that i know have to guarantee everything works before i go over there again....
A 4 port ethernet switch that you guys know can handle STP and RSTP??? thanks again for your help.
Userlevel 2
Sorry for the late reply on this thread but I got the Star Tech EOC110k to work perfectly...

on one side i have an apple airport extreme, a netgear 16 port switch and a star tech EOC110k.. for sonos i have a Sonos Connect hard wired

after about 50 foot of directv cabling i have:

the other star tech EOC110k, a linksys 4 port switch and another airport extreme in repeat mode...for sonos i have another hard wired Sonos Connect.

regarding the original problem with the Gefen EOC boxes, i was actually able to duplicate the problem in another environment so they are definitely the root cause of the issue. I know Sonos doesn't support this but they might want to make a note somewhere for future reference.

Thanks everyone for your help and have a great day!


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