This screen appears if the 'dhcp' option was chosen on the "Network Configuration" screen. This prompt is displayed:
What network device should be used? [eth0] >
At the "" prompt enter the name of the network device you have connected to the internet (or internet connected network) or accept the default (eth0).
If a DHCP server is active on your network, and it provides you with an address, you will see happy dhcp related messages from 'udhcpc' with IP and lease information.
If something isn't right you may receive another message:
Doh: DHCP failed!
Doh: Could not bring eth0 up!
If you cannot get a dhcp address, or you don't have a DHCP server (or device) on your network, you can choose the 'static' option.