getting ping through ip but ping yahoo.com unknown host
 

I have ubuntu installed on my system and testing server centos4. getting ping on gateway ip but cant get ping on yahoo.com unknown host yahoo.com and wget error Resolving www.apache.org... failed: Temporary failure in name resolution.

Do you have the DNS server from your provider in
/etc/resolv.conf?

It should read
type the following command
and add the DNS from your provider

DNS is given nameserver 208.67.220.220
nameserver 127.0.0.1

Any firewall that could block DNS requests on port 53?

What is the output from

;; connection timed out; no servers could be reached

Then there is an issue with the firewall.
Try to disable the firewall.
If you have a router, look if there is a firewall at the router.

i have used /etc/init.d/iptables stop
and used nslookup www.google.com getting error
;; reply from unexpected source: 192.168.132.10#53, expected 208.67.220.220#53
;; connection timed out; no servers could be reached

It may also be that your provider is blocking DNS queries to the opendns.com servers. Does your provider have a DNS server? If turning off your firewall doesn't fix things (if it does, let us know, you don't want to leave it off), you may want to try putting your ISP's DNS server IP's into resolv.conf instead of the opendns.com ones.

HTH

Forrest

are you running in a virtual machine?
what is the exact output of
try to remove everything except

on the virtual machine the downloading is working but not working through the testing server. i have deleted everything except
nameserver 208.67.220.220 and still the same error

More and more it is seeming to me that your ISP is blocking DNS queries to outside servers. They are probably catching all port 53 traffic and directing it to their DNS server (thus the message that your response came from an unexpected source. Try changing your nameserver to 192.168.132.10 or dynamically assigned.

HTH

Forrest