I have 13 Sonos devices.  Three hard hardwired to a router/switch--a Port, a Boost and a One. 

I have assigned fixed IP addresses to every device and rebooted them. 

When everything is working, I can see all the devices are on Sonosnet (WM 0) except the Move.  When I go to a browser and open up the network matrix the signal looks pretty good for all the units. 

Periodically the entire system, except the Move, will disappear.  It just happened today and I submitted a diagnostic report--159866136

It seems as though the only thing that works to bring it all back online is to remove the Ethernet connections and power cycle those three units. I just tried that and now everything is back on line--but on wifi not Sonosnet (WM: 1).  Of course, removing the ethernet connections may have nothing to do with them coming back online--that might just happen randomly.  

I submitted a second diagnostic report after everything came back online. 1152772757