@jweather said:
@mott555 said:AirPlayAirPlay uses Bonjour to discover endpoints. Bonjour is a broadcast protocol that doesn't cross subnets by default. I'm guessing your wired and wireless subnets are different, or something else is filtering out the broadcast traffic between them, preventing automatic discovery. And since this is an Apple product, it works the automated way or it doesn't work at all.
This.
AirPlay works fine over wired ethernet. I have a system at home with a desktop streaming to a hardwired AppleTV fine, and I can do the same from my iPad connected to a Netgear router. When we installed an AppleTV at work we found that nobody could activate AirPlay, though. The button/dropdown never showed up. Wireshark showed there was absolutely no mDNS traffic announding the devices. It turned out our IT guy had disabled mDNS in our access point controller a couple weeks before. Grab a cap with Wireshark and see if you're getting any mDNS traffic.