为什么不能联网？

[root@mylove LINUX_1]# ifconfig
eth0      Link encap:Ethernet  HWaddr 00:13:77:BA:35:49 
          inet addr:192.168.0.170  Bcast:192.168.0.255  Mask:255.255.255.0
          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:185

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:1400 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1400 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:2175240 (2.0 MiB)  TX bytes:2175240 (2.0 MiB)

wlan0     Link encap:Ethernet  HWaddr 00:25:56:AE:A0:B3 
          inet addr:192.168.0.170  Bcast:192.168.0.255  Mask:255.255.255.0
          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)

网卡都能被识别出来，但还是不能上网？？？