configuring ethernet for internet access.

i have booted ubuntu 12.10 in beagle board xm. but while configuring ethernet eth0 is not listed while using the command " sudo ifconfig -a" only usb0 and lo is listed.
can any one highlight the reason for this and how to rectify it. pls find an attachment of the screenshot,

Screenshot from 2014-04-03 11_45_36.png