|Your DNS is being provided to you by your ISP. You are probably not going to be able to ping it but that does not mean it is not working. To test your DNS you need to ping something by its FQDN like...|
It you should resolve and IP for YAHOO and start pinging it. Try the command above and tell us what you get.
You could also try using a
This will flush your local DNS cache and reload. Then do...
And you should see yahoo loaded in your local DNS.