配置环境：

• 操作环境：ubuntu
• 网络连接：USB无线网卡链接WIFI
• 连接方式：wpa_supplicant
• 监测方式：iwconfig

出现情况：

• wpa_supplicant连接成功
• 能ping通网关、路由中也能查看到主机连接上
• 但不能ping通外网

场合：家、公司

ubuntu设置情况如下：

wpa_supplicant连接wifi：

wpa_supplicant.conf设置如下

 # cat /etc/wpa_supplicant.conf
ctrl_interface=/var/run/wpa_supplicant GROUP=wheel

network={
    ssid="TP-LINK_413"
    #psk=""
    psk=e69abb9b46dcbf8df67738a2eda466c54b3f12043e54157d58e097c3e19fa2e3

    proto=RSN
    key_mgmt=WPA-PSK
    pairwise=CCMP TKIP
    group=CCMP TKIP
}

连接wifi：

 # wpa_supplicant -Dwext -iwlan0 -c/etc/wpa_supplicant.conf -dd -B

结果如下：

查看wifi信息

 # iwconfig

结果如下：

至此wifi连接完毕，附上一张路由上的主机列表，划线的就是ubuntu，不过收包、发包太少了

设置网卡IP：

 # cat /etc/network/interfaces
# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback

# auto eth0
# iface eth0 inet static

auto wlan0
iface wlan0 inet static

address 192.168.1.192
netmask 255.255.255.0

# home
gateway 192.168.1.253

# work
# gateway 192.168.1.1

network 192.168.1.253

设置DNS

 # cat /etc/resolv.conf
nameserver 192.168.1.253
nameserver 8.8.8.8

重新启动网络服务

 # service networking restart

结果如下：

启动wlan0：

 # ifconfig wlan0 up
# ifconfig

结果如下：

ping网关

 # vi /etc/resolv.conf
root@cubieboard-server:~# ping -c 4 192.168.1.253
PING 192.168.1.253 (192.168.1.253) 56(84) bytes of data.
64 bytes from 192.168.1.253: icmp_req=1 ttl=64 time=1.90 ms
64 bytes from 192.168.1.253: icmp_req=2 ttl=64 time=1.59 ms
64 bytes from 192.168.1.253: icmp_req=3 ttl=64 time=1.99 ms
64 bytes from 192.168.1.253: icmp_req=4 ttl=64 time=1.60 ms

--- 192.168.1.253 ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3004ms
rtt min/avg/max/mdev = 1.597/1.776/1.999/0.178 ms

ping 外网，失败了

 # ping -c 4 baidu.com
PING baidu.com (123.125.114.144) 56(84) bytes of data.
rtw_set_ps_mode: Leave 802.11 power save
rtl8188e_set_FwPwrMode_cmd: Mode=0 SmartPS=2 UAPSD=0
rtw_set_ps_mode: Enter 802.11 power save
rtl8188e_set_FwPwrMode_cmd: Mode=1 SmartPS=2 UAPSD=0

--- baidu.com ping statistics ---
4 packets transmitted, 0 received, 100% packet loss, time 3008ms

查看route

请问如何解决？怎样能ping通外网