Broadband Adapter

The Nintendo GameCube Broadband Adapter (BBA) and the Nintendo GameCube Modem Adapter are a network adapter and 56k dial-up modem, respectively, for the Nintendo GameCube. They were produced by Conexant and made in the Philippines. The adapters fit flush into "Serial Port 1" on the underside of the GameCube and add an Ethernet port or telephone port to the side of the console, allowing the console to communicate with other consoles through a network.

As of, Dolphin's main branch has BBA emulation support. However, it requires a Virtual Private Network (VPN) in order to function. BBA emulation is not supported on OSX.

For instructions on how to set up a VPN and BBA emulation, use the links below.
 * GitHub Dolphin Wiki: BBA: How to use the Broadband Adapter

Games with BBA/Modem Support
= How to use the BroadBand Adapter =

Windows

 * Install OpenVPN TAP Adapter V9, included in the OpenVPN installer: OpenVPN download page
 * Go to start menu. Click TAP-Windows and then click Utilities. Right click Add a new TAP virtual ethernet adapter and run it as administrator. It will complete in a few seconds.
 * In Control Panel\Network and Sharing Center\Change adapter settings, select the TAP device and the adapter you use to connect to the internet.
 * Right-click and select Bridge Connections.

Linux
Install OpenVPN from your distribution package manager, then run the following commands (as root) to create the virtual interface and bridge it to your physical Ethernet adapter: openvpn --mktun --dev Dolphin --dev-type tap brctl addbr br0 brctl addif br0 Dolphin brctl addif br0 eth0   # or whatever your network interface is ip l set Dolphin up ip l set Dolphin promisc on You'll also need to change your network settings to configure IP/gateway on br0 instead of your usual adapter. Linux doesn't support adding a wireless interface to a bridge as of July 2012 so you need a wired NIC for that to work.

Configure Dolphin
Config -> Gamecube -> SP1, select BBA.

Now you may play any games which use the BBA.