"Do you have another machine within the same network to ping to?"

Yes, I have a PC connected through Ethernet card (via cable) and I'm able to to connect to internet and to my router.

"BTW, do you mean at the beginning you run knoppix inside one of the virtual machine on the top of vmware server?"

No, of course I simply run knoppix from DVD, I have just installed Vmware, but no virtual machine was running.