Verify that your router will let this computer get its config via DHCP. It sounds like it might be getting refused.
Check /etc/resolv.conf
Here's what mine looks like:
cat /etc/resolv.conf
# Generated by NetworkManager
domain grandenetworks.net
search grandenetworks.net
nameserver 192.168.0.1
My router is 192.168.0.1
It forwards the DNS requests to the DNS servers it has set up within its config.
Another good test to verify connectivity to the outside network is to find the IP address of a computer and try pinging it by IP.
nslookup slashdot.org
Server: 192.168.0.1
Address: 192.168.0.1#53
Non-authoritative answer:
Name: slashdot.org
Address: 216.34.181.45
root@pirate-chest: ping 216.34.181.45
PING 216.34.181.45 (216.34.181.45) 56(84) bytes of data.
64 bytes from 216.34.181.45: icmp_seq=1 ttl=242 time=50.7 ms
64 bytes from 216.34.181.45: icmp_seq=2 ttl=242 time=46.4 ms
64 bytes from 216.34.181.45: icmp_seq=3 ttl=242 time=44.5 ms
64 bytes from 216.34.181.45: icmp_seq=4 ttl=242 time=46.0 ms
64 bytes from 216.34.181.45: icmp_seq=5 ttl=242 time=46.2 ms
^C
--- 216.34.181.45 ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4017ms
rtt min/avg/max/mdev = 44.579/46.819/50.770/2.087 ms
Obviously, you'll need to do the nslookup on a computer with a valid connection to the internet. Or, you can use the IP for slashdot I've provided above. If that test fails, then you know that not only is DNS broken for your system, your router is refusing traffic from this machine to the outside world.
di11rod