This may be a networking question as much as an Apple-specific question; however it's directly related to configuration / behaviour of Apple Remote, so hoping to find an answer here.
My goal: Build a USB-powered music server to be used in my car. Control it via the iTunes remote app on my iPhone. Enable direct wireless connection between iPhone and music server without any additional network infrastructure.
- Apple Remote (latest version from App Store) running on iOS 7.1.1.
- Raspberry Pi running forked-daapd, an iTunes-compatible media server with support for Apple Remote. It's also running Shairport which is an Airplay-compatible receiver.
- Edimax EW-7811UN USB wireless adapter attached to the Raspberry Pi.
The Pi is configured to act as a wireless access point and assign IP addresses via DHCP to any devices that connect to it. It has no other network interfaces, so has no internet connectivity.
My iPhone is connected directly to the wireless network broadcast by the Pi. I can successfully stream music to the Airplay receiver on the Pi, and have also paired the Remote app on my iPhone with the forked-daapd server on the Pi and can control the library from my iPhone.
The problem is connecting to the Pi's wireless network prevents the iPhone from accessing the mobile data network, as it tries to route internet traffic over the wireless network, and the Pi has no internet connection.
This is easily resolved - configure the Pi's wireless access point not to assign a router/dns server. So only an IP address and subnet is provided to DHCP clients. In the case of the iPhone, this means it will continue to route internet traffic over the mobile data connection, and send local traffic for addresses on the wireless network to the Pi.
With this configuration, I can still successfully stream audio via Airplay to the Pi, whilst simultaneously accessing the internet over the iPhone's mobile data connection. However, it prevents the Remote app from finding the library on the Pi. Even with "Stay Connected" enabled in the Remote app settings, as soon as I remove the router/dns settings from the Pi's wireless access point DHCP config and renew the DHCP lease on the iPhone, Remote can no longer connect to the library.
I'm assuming that mDNS is working correctly, as the Airplay receiver is still discoverable by the iPhone. Does anyone know what could be causing Remote to fail to see the library, and how I might go about resolving this issue?