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
/etc/nsswitch.conf
, especially on the line that starts withhosts:
? You should havedns
somewhere on that line.dig
,host
andnslookup
do not use the name service switch (as they don't need to consider other name service mechanisms than DNS). Most other software uses it. It is part of libc, andman nsswitch.conf
on the command line will give you rationale and overview.