Collaborator I

Sonos Amp becomes unreachable on UniFi after some time (no ping / no ARP, link still up)

Forum|Forum|5 months ago
April 25, 2026
22 replies
560 views

Hi everyone,

I’m running into a recurring issue with my Sonos Amp in a UniFi network and wanted to check if anyone has seen something similar or has a working setup with current UniFi firmware.

Setup:

Sonos Amp
Ubiquiti UniFi network system (UDM Pro + switches)
Amp connected via Ethernet (also tested via WiFi)
Flat network during testing (no VLAN separation)

Problem:
After a reboot, the Amp works fine. But after some time (hours to days, even when idle), it becomes completely unreachable:

disappears from the Sonos app
cannot be pinged
does not respond to ARP requests

In UniFi, the behavior varies slightly:

sometimes the device is still shown as connected but greyed out
other times it disappears entirely as a client
however, the physical link LED on the switch port remains on

Only a full power cycle brings it back. Replugging Ethernet alone does not help.

What I already tried:

Ethernet and WiFi (same behavior on both)
Disabled WiFi when wired
IGMP Snooping + Querier enabled
RSTP enabled, STP Edge on the ports
Forced 100 Mbps Full Duplex
Disabled PoE on the port
Tested different cables and switch ports
Monitoring via ping (device stops responding entirely when the issue occurs)

From what I can tell, when the issue happens the Amp stops responding at a very low level (no ARP replies), even though the physical link remains up.

Background:
Interestingly, I had a very similar issue about two years ago. Back then I was able to resolve it by adjusting some UniFi settings (related to multicast / network behavior).

However, after various UniFi updates, those settings either changed or are no longer available in the UI, and I haven’t been able to reproduce the old working configuration.

Question:
Is anyone currently running a stable setup with the Sonos Amp on UniFi?

Are there any specific UniFi settings (current firmware/UI) that are known to fix this?
Has something changed in how Sonos interacts with UniFi?
Or does this sound like a faulty device after all?

Would really appreciate any insights or current best practices for Sonos + UniFi.

Thanks a lot!

Robert

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Show previous replies

buzz

I suggest submitting a series of three diagnostics: one while the system is working, one immediately after the AMP goes offline, and one immediately after you get AMP back online, then call SONOS phone support.

buzz

As I recall, depending on the model, not all UBIQUITI switch ports will provide PoE and PoE can be disabled on a port by port basis.

C

craigski

Local Superstar

I ran another test to further isolate the issue: I connected a small unmanaged switch (different brand) to my UniFi switch, and then connected the Sonos Amp and another unrelated device (a printer) to that switch.

The result was quite interesting:

the Amp disappeared again shortly after
the printer remained connected and reachable without any issues

This suggests that the UniFi switch itself is not blocking the port.

At this point, I think there is a real possibility that the Amp itself is becoming unresponsive or crashing. However, I am not sure how to narrow this down further.

Has anyone seen similar behavior or has ideas for additional tests?

See my response to your questions in the other thread, there is some duplication here.

The NinthAuthor

Collaborator I

See my response to your questions in the other thread, there is some duplication here.

Responding here, to avoid that duplication.

Yes, no need to wire Sonos in 2026, unless a high density rack solution. Spend you time listening to Music, rather than managing Ethernet ports, STP loops, etc 😀 That's what you did two years ago to fix the problem?

That’s a good question. Back then I mainly adjusted a few UniFi settings, which improved the situation, but the system was never completely stable. Even at its best, I still had to restart the Sonos Amp roughly every couple of weeks.

I’m not sure what changed to make things worse now. It could be UniFi updates, Sonos firmware updates, or a combination of both.

Regarding WiFi: I also tested the Amp in isolation. I powered off the other Sonos devices and connected only the Amp via WiFi, with Ethernet disconnected. Even in this setup, it disappeared again after less than 30 minutes.

The NinthAuthor

Collaborator I

I contacted Sonos support today regarding this issue.

Based on the behavior, especially that the Sonos Amp does not respond to anything at all when it goes offline, not even the buttons on the device, they believe it is defective.

Sonos will send me a replacement.

buzz

Good! Please follow-up here after the new unit arrives.

The NinthAuthor

Collaborator I

Yes, I will keep you posted!

The NinthAuthor

Collaborator I

The replacement Sonos Amp arrived on Thursday and I set it up the same afternoon. It has been stable since then, so more than 50 hours now.

I’m cautiously optimistic that the issue was indeed caused by a hardware defect.

I have network monitoring in place and will be notified if the device becomes unreachable, so I’ll continue to keep an eye on it.

buzz

Thanks for the follow-up. I think you are out of the woods now.

F

fpskywalker

Lyricist I

Similar situation for me, I have a UDM Pro with 2 APs. All Sonos Devices are on WiFi. What ended up fixing the Sonos Amps getting disconnected was changing the 2.4Ghz Radio Channels from Auto to specific channel. What I noticed is that when in Auto, the UDM was placing both APs on the same channel-1 for 2.4Ghz.

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