Mosaic losing contact with MinimServer

We have a client with a Vivaldi system (sans transport) that is reporting problems maintaining contact with MinimServer running on a Synology NAS array. He has recently changed his LAN equipment to an Eero system, but he says this particular problem predates the network equipment change. Here are his comments:

The Mosaic app has always maintained communication with the upsampler and Qobuz (and previously TIDAL) streaming has remained unaffected, except when system wide network problems have arisen. Selecting UPnP in Mosaic (on the other hand) yields “No UPnP servers available”. Today this happened even while listening to normal playback of files located on the Synology NAS, rendered via UPnP/ MinimServer. To reiterate, files were rendered via UPnP/MinimServer while the Mosaic reported “No UPnP servers available”.

And, from the technician who installed the Eero system:

As far as the dCS is concerned, it is odd that the connection drops. This could be a result of multicast advertisements failing to update on the dCS side of things. Unfortunately, Eero does not have any settings to adjust or disable multicast broadcasting. If you are unable to resolve this with the dCS, we can try putting an inexpensive router in front of the Eero to disable multicast broadcasting.

Apparently, this has happened with both the long-time MinimServer version,, and the newly released 2.0

Thanks in advance, Andrew!

The key detail here is missing. What is the actual network configuration? What’s plugged into what?

I’m going to take a wild guess here and say that there’s a switch involved and that this switch pre-dates the addition of the eero hardware. If so I’m betting that it’s some sort of managed or “smart” switch which is periodically blocking multicast.

If there is a switch then swap it out for a dumb switch. I used to recommend the Cisco SG-1xx products, but it looks like they’re being discontinued. Still worth buying if you can find one. Next best is the Netgear GS-108 (in the blue case, not the grey case).

I’ve seen a few dumb switches that break multicast. Most notable among those are the products from DLINK. I know first hand that both the Cisco and Netgear products work without issue.

Also, the eero has proven to be a somewhat unreliable device when UPnP is in play. I have one in my test kit and although it works some firmware releases have been more problematic than others.

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Here’s the info I have from our client:

Xfinity is the ISP. A Netgear CM600 cable modem connects to the gateway Eero Pro which then passes signal to two additional Eero units via Cat5 Ethernet wiring (my note : the CAT 5 was already in the walls of the house, and it is not feasible to upgrade it to 5e or 6). The Vivaldi Upsampler and Synology NAS array are connected to the network by a TPLink TL-SG108 switch, the VPP with a short run of Transparent Ethernet to the switch, the NAS array by a longer in-wall run of Ethernet cable to the switch, as it is in another room.

I have now found out that the TPLink switch was added to the network architecture when the Eero Pro gear was installed last week. Is that the likely culprit?


These are the marketing bullet points for that switch.

Items 2, 3, and 5 are all red flags in my book when 5 and 6 are combined that sets off further alarms that this switch should be avoided at all costs as the network would be more reliable if it were wired with cans and string (or smoke signals).

Seriously, this POS is the answer to a question that no one ever asked. If the customer has a door that needs to be propped open or needs a parking block in his garage then #4 on that bullet list suggests that it might be useful. Otherwise it shouldn’t ever be plugged into an actual network.

Joking aside, I’m 98% certain that switch is the problem. Track down a Netgear GS-108 (the blue one) or a Cisco SG110-08 and there should be an improvement.

As a total aside (and for the record) this is fine. Technically regular CAT5 doesn’t have the proper configuration to certify for gigabit (hence the creation of 5e), but it’s really close and in most residential applications it works just fine. About 50% of the wire in my old house was CAT5 (with the other 50% CAT5e) and the two were indistinguishable in practice. I’ve yet to see a residential application in which CAT6 makes sense and when I wired my new house last month I did 39 drops of CAT5e.

Thanks as always!

We are finding a Cisco SG110D-08 - do you know if the ‘D’ added signifies anything deleterious?

Honestly, no pun intended…

IIRC the ‘D’ signifies ‘Desktop’ and is a reflection of the form factor. That’s the one you want!

Andrew -

Unfortunately, the Netgear GS 108 did not do the trick. Here is my client’s report:

*The Netgear switch arrived this afternoon and I couldn’t put it into use quickly enough. It is nice to have a true plug and play device. I’m starting to think that UPnP is short for “you Pay and Pay?” I was hoping to pack up the TPLink switch, wrap it in pretty paper and bows, then send it to Andrew at dCS along with a insipid fan letter…BUT…the upsampler still reverts to “No UPnP servers available” within 15 minutes of launching it. *

I have only spent an hour or so with it, but both times that I have power cycled the upsampler (to recapture the Synology unit) the connection has gone on to fail. My Sony TV has maintained a continuous connection with MinimServer. With the Sony configured in the same manner as the upsampler, I have been skeptical (but hopeful) that the switch swap would do the trick. Why would one device hold the connection while another fails? I shared that previously, which really points a hard finger at the upsampler.

I don’t know whether this is insightful or not- over my head- but the upsampler image in the Mosaic app was displayed in duplicate during my last trial (see attached image from my iPhone 11).

*As I draft this note, something even more bizarre just happened. The system spontaneously started playing the last track I selected while using MinimServer, after 15-20 minutes of silence. Going quickly to the Mosaic app. and selecting UPnP I see “No UPnP servers available”. Below that I see the album art/ data and status bar, where I can pause, play, advance to the next track, go back to the previous one… but cannot do anything else within the app. *

Is it time to send the upsampler off for evaluation? Other troubleshooting ideas? Thanks.

I have asked him to download the system log for me to forward to you, thinking you might want it.


Weird - I tried to put his report all in italic - formatting took for not all paragraphs…