PING 
root@server1:/home/server1# ifconfig
eth0      Link encap:Ethernet  HWaddr 00:23:ae:27:b9:ec  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
          Interrupt:16 

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:41 errors:0 dropped:0 overruns:0 frame:0
          TX packets:41 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:3589 (3.5 KiB)  TX bytes:3589 (3.5 KiB)

wlan0     Link encap:Ethernet  HWaddr 00:24:2c:49:d1:d8  
          inet addr:192.168.1.6  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::224:2cff:fe49:d1d8/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:54 errors:0 dropped:0 overruns:0 frame:6492
          TX packets:100 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:5617 (5.4 KiB)  TX bytes:12808 (12.5 KiB)
          Interrupt:17 Base address:0xc000 

root@server1:/home/server1# ping6 localhost
PING localhost(localhost.wmcomputersystems) 56 data bytes
ping: sendmsg: Network is unreachable