Recently I bought a Raspberry Pi. My plan was to use this tiny computer as a lighting controller for my band on stage. I have installed the Open Lighting Architecture (OLA) daemon to talk to a cheap FT232 based DMX interface I bought from ebay and developed a simple lighting controller software in python which uses the OLA ClientWrapper API to talk to the DMX interface.
To make the DMX interface work, I needed to update the Raspberry kernel as the preinstalled kernel had some issues with the DMX interface. Kernel updates are easy using the rpi-update script from Hexxeh: https://github.com/Hexxeh/rpi-update
Once everything was working, I tried to run the Raspberry Pi standalone without a network. This is the scenario on stage. Only the Raspberry Pi connected to the light fixtures via DMX. In this scenario OLA refused to start because it was searching for a network interface and ignoring the loopback interface.
A simple workaround is to configure a static ip address for eth0. But then you can no longer use DHCP when connecting to your normal network.
To keep DHCP capabilities and provide a backup network interface when the Raspberry Pi is not connected to a real network, I added a new virtual network interface with a static ip address.
Edit the file
/etc/network/interfaces and add the following lines:
The above configuration will create a new virtual interface
eth0:0 with a static ip address. Make sure that this address is not conflicting with your network.
Now OLA will start without issues even if it is not connected to a network. On stage, I just plug in the Raspberry Pi and once it is booted I can playback scenes via a small USB keypad. No display and no network needed.