I have a Ubuntu desktop. I am running a virtual windows machine using virtual box. Few days before Internet is not working in Ubuntu but it is working in the virtual machine. Even the samba shares are also accessible. I don't know why internet is not working in the base machine. I have tried to ping google.com, but it returns

Ubuntu@desktop:~$ ping google.com
ping: unknown host google.com

ifconfig command's output

Ubuntu@desktop:~$ ifconfig
eth0      Link encap:Ethernet  HWaddr 00:27:0e:1b:86:2a  
          inet addr:192.168.1.7  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::227:eff:fe1b:862a/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:38221 errors:0 dropped:0 overruns:0 frame:0
          TX packets:28161 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:39144616 (39.1 MB)  TX bytes:6143919 (6.1 MB)
          Interrupt:27 Base address:0x2000 

eth0:0    Link encap:Ethernet  HWaddr 00:27:0e:1b:86:2a  
          inet addr:192.168.2.7  Bcast:192.168.2.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          Interrupt:27 Base address:0x2000 

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:14944 errors:0 dropped:0 overruns:0 frame:0
          TX packets:14944 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:1735451 (1.7 MB)  TX bytes:1735451 (1.7 MB)

vmnet1    Link encap:Ethernet  HWaddr 00:50:56:c0:00:01  
          inet addr:192.168.243.1  Bcast:192.168.243.255  Mask:255.255.255.0
          inet6 addr: fe80::250:56ff:fec0:1/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:77 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

vmnet8    Link encap:Ethernet  HWaddr 00:50:56:c0:00:08  
          inet addr:172.16.162.1  Bcast:172.16.162.255  Mask:255.255.255.0
          inet6 addr: fe80::250:56ff:fec0:8/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:78 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)