Airport extreme after linsys router not finding my synology disc/sonos system My airport extreme is configured as bridge after a linksys (wifi) router. Using the airport I don't see the shared folders on my synology(DSM 4.2) in finder, except by connecting through the IP. This also means timemachine doesn't work using the airport network. Synology has fixed ip in network. Using the linksys wifi network or networkcable everything works fine. Same problem for my sonos system that isn't discovered  through the airport network except after switching to the linksys network first.
Your AirPort Extreme will need to "control" the network in order for this setup the way you expect. The Linksys would have to be configured as a bridge with the AirPort Extreme as the router/DHCP server.

Do not that the way you have things setup currently, Time Machine will still work; however you will need to connect to the server/disk by IP address. Other features like Bonjour Sleep Proxy and Back To My Mac just won't work.