Hi

Can you tell us what router you have please?

Hi

It’s an EE Smart Hub (UK)

I wonder if that is linked to the BT Smart Hub issue: BT Smart Hub 2 - Connection Issues (April 2021) | Sonos Community

Thanks - I’d seen that but not sure if EE / BT routers share commonality

There are similarities but I'm not sure if at the firmware level. However, it might be worth turning the 5gHz off and testing.

Hi @n1ckbarnes 

It sounds like the Apple TV is flooding your network with misdirected multicast or failed transmission packets when it is turned on. This is making the router respond to thousands of unnecessary packets and your Play:1 and it’s music stream are getting lost in the noise. 

How does your Apple TV connect? If it connects via WiFi, I recommend removing it from the immediate vicinity of other WiFi devices. If it connects via ethernet, it might be worth replacing the cable.

I recommend recreating the issue, immediately submitting a diagnostic afterwards (after turning the Apple TV off again and without rebooting Sonos) and then getting in touch with our technical support team - if they confirm multicast flooding, it may be best to connect the Apple TV via a IGMP-enabled ethernet switch (cheap - less than £$€50), or activate IGMP Snooping/filtering on your router, if it has that option.

Thanks @Corry P - everything connecting to the router is wireless.

I’ve changed the static ip addresses and rebooted the router and that seems to have cured the issue for now (I’ve not been able to recreate the issue since :))

I’ll bear in mind your suggestions should the issue reoccur

Hi @n1ckbarnes 

Fantastic - good thinking!

There mayhave been an IP conflict with Apple TV and a speaker.

Problem is reoccurring and seems to get progressively worse each day - as soon as Apple TV is switched on, SONOS radio stream stops and trying to view the speakers via the SONOS phone app / PC app fails to find my SONOS network. I suspect that rebooting the router did more than making the IP addresses static. After a period of time, the SONOS app ‘recovers’ and finds the speakers again and I can resume listening to music. Guess I need to investigate IGMP filtering :) 

Hi @n1ckbarnes 

If your router doesn’t have IGMP as an option, you can purchase a small IGMP-enabled network switch for under 40 creds ($£€). Connect the Apple TV to your network via the switch and the flooding will disappear.

It doesn’t, so I’ll have to raid the piggy bank. Interestingly, my router is “related” to the BT router in the link above, and I have split 2.4 / 5 GHz channels, but apparently it’s not affected…..

Thanks for your advice @Corry P :)

Hi @n1ckbarnes 

You’re very welcome!

Even if the BT router and the EE router were the same physically (internally, anyway), the EE router would never receive a firmware update from BT so you won’t be affected by that issue, just as @UKMedia suggested.

I should mention that if you have a Sonos device wired to your network via ethernet, you should connect that via the IGMP switch too.

I do recommend you first get in touch with our technical support team who will confirm that multicast is indeed the problem, before spending any money - unless you don’t mind returning the switch if it doesn’t help.