I was trying to compare VMWare and VirtualBox. I ran Ubuntu 10.04 Server Edition on both virtualization program, and both had the same problem with the Internet connection. When I tried to run “sudo ifup eth0”, system showed something like “eth0: ERROR while getting interface flags: no such device”.

Once again I found the solution in the ubuntuforums.org. It suggestes me to delete these lines below from “/etc/udev/rules.d/70-persistent-net.rules”

PCI device xxxxxxxxxxx (module)
SUBSYSTEM==”net”, DRIVERS==”?*”, ATTRS{address}==”xxxxxxx”, NAME=”eth0″

But, I deleted the file instead, I restarted the system, and then the Internet connection was fixed. This solution is applied to both virtualization program.

Reference:
http://ubuntuforums.org/showthread.php?t=255018