Best answer by ratty
Note however that whatever you wire them to needs to support STP (Spanning Tree Protocol). Sonos uses this to avoid network loops. Unmanaged (dumb) switches and most routers should be fine, as they'd simply pass STP transparently. If you have managed switches they're likely to need STP ('classic STP') enabled explicitly.
With a small system such as yours you could simply daisy-chain:
router -> Boost -> Connect -> Connect
This would avoid any STP troubles.