I am not able to browse any websites. Please take a look at the following error:

karthick@karthick:~$ ping www.google.com                         

ping: unknown host www.google.com

Update

karthick@karthick:~$ dig www.google.com



; <<>> DiG 9.7.1-P2 <<>> www.google.com

;; global options: +cmd

;; Got answer:

;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 26402

;; flags: qr rd ra; QUERY: 1, ANSWER: 6, AUTHORITY: 4, ADDITIONAL: 4



;; QUESTION SECTION:

;www.google.com.            IN  A



;; ANSWER SECTION:

www.google.com.     238583  IN  CNAME   www.l.google.com.

www.l.google.com.   97  IN  A   74.125.236.50

www.l.google.com.   97  IN  A   74.125.236.48

www.l.google.com.   97  IN  A   74.125.236.52

www.l.google.com.   97  IN  A   74.125.236.49

www.l.google.com.   97  IN  A   74.125.236.51



;; AUTHORITY SECTION:

google.com.     146866  IN  NS  ns3.google.com.

google.com.     146866  IN  NS  ns2.google.com.

google.com.     146866  IN  NS  ns1.google.com.

google.com.     146866  IN  NS  ns4.google.com.



;; ADDITIONAL SECTION:

ns2.google.com.     317814  IN  A   216.239.34.10

ns1.google.com.     317814  IN  A   216.239.32.10

ns3.google.com.     317814  IN  A   216.239.36.10

ns4.google.com.     317814  IN  A   216.239.38.10



;; Query time: 5 msec

;; SERVER: 172.29.39.212#53(172.29.39.212)

;; WHEN: Wed Aug  3 15:30:38 2011

;; MSG SIZE  rcvd: 268

Output:

karthick@karthick:~$ ifconfig

eth0      Link encap:Ethernet  HWaddr bc:30:5b:c4:fd:dc  

inet addr:172.29.XX.XX  Bcast:172.29.XX.XXX  Mask:255.255.255.0

inet6 addr: fe80::be30:5bff:fec4:fddc/64 Scope:Link

UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

RX packets:1757954 errors:0 dropped:0 overruns:0 frame:0

TX packets:1422948 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:1000 

RX bytes:1329324192 (1.3 GB)  TX bytes:1231317787 (1.2 GB)

Interrupt:16 



lo        Link encap:Local Loopback  

inet addr:127.0.0.1  Mask:255.0.0.0

inet6 addr: ::1/128 Scope:Host

UP LOOPBACK RUNNING  MTU:16436  Metric:1

RX packets:10528 errors:0 dropped:0 overruns:0 frame:0

TX packets:10528 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:0 

RX bytes:768164 (768.1 KB)  TX bytes:768164 (768.1 KB)



karthick@karthick:~$ sudo iptables -nvL

[sudo] password for karthick: 

Chain INPUT (policy ACCEPT 0 packets, 0 bytes)

pkts bytes target     prot opt in     out     source           destination         



Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)

pkts bytes target     prot opt in     out     source           destination         



Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes)

pkts bytes target     prot opt in     out     source               destination