Ok that shows that you can get to the other machine how about when you try to go outside the network using the www.cnn.com or 64.236.24.28 (one of the IP address for cnn) can they be reached? What is the contents of the /etc/resolv.conf when booted from the CD your nameserver should be in there automatically, when booting Knoppix should have got that information from the DHCP server.