To confirm that this actually works do: $ nslookup gnu.org on your own machine.
This works
Good.
[ If you can not have a DNS then try: $ ping 199.232.41.10 If this fails, then read on.]
This does not - dest unreachable
Do you have a gateway? Remeber a proxy and gateway are different although they can be on the same machine. If you have a gateway then it is not forwarding ICMP ECHO packets. Can you do: $ traceroute google.com
I still would like to know what you are trying to achieve? Anything particular you want?
Cheers, Debarshi