Spanning Tree issues on TP-Link/Omada after replacing downstream/edge switch.

My first question would be what provides your normal WiFi throughout the house and is it a mesh system, i.e. more than one unit? Second would be does it work well? 

I looked into this when I got a managed/smart switch. Didn't take me long to return the switch and hook my Sonos back to my dumb ones. I'm sure there are more technical solutions but I wanted music, not frustration.

I use UniFi managed switches without issue but the best practice applies to other manufacturers, use either WiFi or wired never mix the two in a household. If wired disable WiFi on all Sonos devices. 
 

You could try disabling WiFi on just the two wired Sonos devices and hopefully this will stop the STP loop.

The reason I asked if your existing non-Sonos WiFi is good or not is because the version of STP Sonos use on Sonosnet is very old and not very easy to get going with other more modern devices. It’s very easy for it all to get confused. Any modern mesh WiFi system (even if you only use one unit) will not play nicely with Sonos unless your managed switch can translate between old and new STP implementations. Cisco can do this for example. However… it’s a ball ache to be frank. The simplest solution is to abandon Sonosnet and then STP does not matter. If you have a managed switch, the best thing to do here is to disable STP on the ports Sonos devices are on if it lets you. 

Then configure Sonos to just use your main WiFi which these days is way more robust than when Sonosnet was a good idea. 

The other thing on a managed switch that you need to get right is multicast or IGMP. It’s probably best to have your WiFi or the router that provides NAT to run the IGMP querier process, but your managed switches should deploy IGMP snooping. This allows the switch to look at IGMP requests so it can only send packets to ports with interested devices and not flood the whole network with multicast packets. Get this wrong and speakers will fall out of groups or not join and drop audio… 

To disable Sonosnet, power off all Sonos devices then power on and connect the ethernet connected devices one at a time and go into the settings in the iOS app to disable WiFi. Then do the next one. The big caveat here is if you have a soundbar, you cannot disable WiFi if you use a Sub or surround speakers as the soundbar needs WiFi to communicate with them, so to not get Sonosnet you can’t wire in any soundbar that supports Sonosnet. When you then turn on the WiFi only devices, as there is no Sonosnet available they use the main WiFi. 

The reason I asked if your existing non-Sonos WiFi is good or not is because the version of STP Sonos use on Sonosnet is very old and not very easy to get going with other more modern devices.

I read that somewhere, but I thought I read the plain “STP” setting was the old version. But maybe that explains why SonosNet isn’t split between the two ethernet-connected speakers.

I don’t have mesh wifi, I have hard-wired APs. The SonosNet is on a separate channel from my APs, so it has not been a big issue.

but your managed switches should deploy IGMP snooping. 

I need to research that more. TP-Link support suggested enabling IGMP, but I’ve toggled it both ways and I see no difference.

Then configure Sonos to just use your main WiFi which these days is way more robust than when Sonosnet was a good idea. 

That’s probably the right approach. My 2.4G band is pretty quite, which is what Sonos uses (for wifi, too, not just SonosNet?) Just a bit of a pain to plug in each speaker -- sure wish there was more ethernet in the walls!

And there’s no reason some speakers can’t still be hard-wried in that case, correct?

Now I have to decide if it would be smart to create a separate Sonos VLAN -- and what all I’d break doing that...

Just to satisfy my curiosity, if everything was configured correctly (and I had the right version of STP on my network equipment), would SonosNet split between two more more hard-wired speakers? Is that what the “STP state” in the Sonos matrix was supposed to indicate?

Thanks.

“Plain” STP comes in two different types, short and long cost path values. Sonosnet uses the very old short values which will cause problems with anything expecting long ones. Some switches allow you to customise etc. but like I say, I think your time is best spent getting your normal WiFi running well and getting rid of Sonosnet. 

Unless all your kit is really old, things like Play:3’s, Play:1’s, One’s etc. can run on 5GHz, not just 2.4. 

Although people often recommend either plug all or plug none, you can mix & match, you just have to follow the sequence I posted to make sure you don’t accidentally create Sonosnet. New Era Sonos speakers don’t support Sonosnet at all. 

A separate VLAN with Sonosnet may cause you all sorts of headaches. In this scenario you may have to route multicast between VLAN’s, which can be complicated. Or if you try and keep them fully independent, your switch will need to provide the IGMP querier function for the Sonos VLAN and not interfere with that function on your main WiFi which is used by quite a few things these days like smart TV’s and even Philips Hue. 

I looked at VLANs and decided they were more frustration than I wanted to deal with.

For me just using one of the other LAN ports on my router was far simpler, just move an Ethernet wire or two. Moved the Access Point, NAS and my (back then) wired Sonos to it. Then went back and started moving other things that were not happy crossing LANs. Looked at the final result and realized I'd accomplished nothing by all this and went back to a single LAN.

​@Ian_S: Although people often recommend either plug all or plug none, you can mix & match, you just have to follow the sequence I posted to make sure you don’t accidentally create Sonosnet.

It’s surprisingly hard to find info on NOT creating SonsNet when connecting to ethernet, yet still leave the device’s wifi enabled. Is that at all not possible?

Does not sound like it:

To disable Sonosnet, power off all Sonos devices then power on and connect the ethernet connected devices one at a time and go into the settings in the iOS app to disable WiFi. Then do the next one. The big caveat here is if you have a soundbar, you cannot disable WiFi if you use a Sub or surround speakers as the soundbar needs WiFi to communicate with them, so to not get Sonosnet you can’t wire in any soundbar that supports Sonosnet. When you then turn on the WiFi only devices, as there is no Sonosnet available they use the main WiFi. 

I don’t have ethernet cable available everywhere, so I have to use home wifi or SonosNet.

And unfortunately, I have a Soundbar with a Sub and two surrounds, which requires wifi to be enabled, in a place where home wifi is not the best. But, there’s ethernet available at the Soundbar.

So, if I plug in the Soundbar to ethernet, and all my other speakers have Wifi enabled, that will cause other speakers in range of the Soundbar to switch over to SonosNet.

It’s very odd that is not possible to disable SonosNet as it’s very common to have devices that can be connected to either (like a laptop).

I do have a number of Play:1 (and Sonos One’s) connected in stereo pairs. From my understanding, unlike the Playbar, stereo pairs do not use 5GHz to talk directly to each other. That is, for those, if one is connected to ethernet just disable its wifi.

There is no control other than the horribly mislabeled "disable wifi" available so your choice is:

1. Internal radio on

2. Internal radio off

Many requests for more flexibility on enabling Sonosnet but the Sonos plan seems to be focused on Wi-Fi setups for the majority of users while keeping the ability to connect to Ethernet (without Sonosnet) as an extra cost option on the newest gear.

Fix the WiFi? If it was me, I would unplug all Sonos and setup in Wireless Mode, and where you have an ethernet connection and poor WiFi (eg in your example above) plug an AP in. If you have poor WiFi, then your controller(s) will struggle, even if your wired SonosNet is working after juggling with STP configuration. In Sonos Wireless Mode, you will free up an additional 2.4GHz channel used by SonosNet and use for your new AP.