Problems solved - Home Sharing and Wi-Fi sync'ing - needed sep. network on 5 GHz Wi-Fi
I've had no end of issues with Home Sharing between my mid-2010 Mac Mini and my Apple TV 2, as well as Wi-Fi syncing between iTunes on the same Mac and both of my iOS devices (iPhone 4S and iPad 2). None of the fixes or workarounds, from Apple's own Support pages or elsewhere, solved these problems for me. The following steps did, however:
My home network consists of a cable modem, connected via Ethernet to a 5th-generation Airport Extreme. This Airport creates my wireless network. A second Airport (also 5th gen.) then connects wirelessly to the first to extend my network. Originally, the first Airport operated [a single network] in dual-band (2.4GHz and 5GHz) mode. And the second was set to "allow wireless clients to connect" via Airport Utility.
This second setting caused several issues, e.g. a WiFi printer detecting two identical networks with the same SSID. I disabled this feature, which resolved many issues, except for the ones stated in the subject line. (It may have helped fix this, though - I'm not sure.)
Thus, on to the first Airport. I changed its settings such that on the 5GHz band, the network had a different name. I also set up the 2nd Airport to extend this network, and not the other on the 2.4GHz band. I then added this "new" network to the Mac's Network > WiFi preferences, and made it the 1st network on the list of preferred ones. (The 2.4GHz network is 2nd.) Finally, in the Apple TV's Wi-Fi settings, I connected to the 5GHz network instead of the 2.4GHz one.
And... Success 😀 Home Sharing have remained rock-solid for days now between the Mac and the Apple TV; the best I could ever do before was a couple of hours. And both my iPhone 4S and iPad 2 both sync reliably with the Mini. I even changed the iPad's network to the 5GHz one, and WiFi sync'ing with iTunes continues to "just work." I also tried an Ethernet connection between the Apple TV and Airport #2, which never worked previously but does so now, and reliably.
So I have to conclude that Home Sharing and Wi-Fi cync don't handle dual-band networks. I submitted the above as feedback to Apple; I hope this helps with future updates to iOS, Apple TV OS, and iTunes (Home Sharing), as well as Airport Utility, Airport firmware, and OS Lion.
PS: some of the "solutions" that did not work include:
- setting WiFi channels manually
- not clicking "Done" when starting Home Sharing
- disconnecting iOS devices from their USB cables without ejecting the devices in iTunes
- playing with iPv6 settings
