I have a Raspberry Pi Model B, running Raspbian Wheezy, with an attached (and fully functional) Ourlink USB wireless card. However, upon making a wired Ethernet connection, the wireless network is disconnected. Is there any setting I can change to prevent this? I have verified that both wireless and wired connections can function simultaneously, by manually re-enabling the wireless connection over the wired connection.
In the /etc/network/interfaces file, change the line
Explenation is that wpa-roaming is a method with which you can browse and connect to wireless networks.
The result of the following setup is that if an ethernet cable is not attached, wlan0 takes precedence and connects you to your desired wireless network or to an available open wireless network or a predetermined wireless network. If you connect an ethernet cable, the cabled network connection immediately shuts down WiFi access and eth0 then connects you to the cabled network. By unplugging the network cable the wireless connection will instantly be available again.
I assume that, wpa-conf is the static configuration which not needed for roaming through network interfaces. I couldn't find any relevant and detailed document for this.