1. 安装 wireless_tools 和 madwifi
pacman -S wireless_tools madwifi
2. 查看网卡状态
lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 002: ID 093a:2510 Pixart Imaging, Inc. Optical Mouse
Bus 001 Device 003: ID 0cf3:7015 Atheros Communications, Inc.
在USB接口001/003上检测到网卡。
iwconfig
lo no wireless extensions.
eth0 no wireless extensions.
wlan0 IEEE 802.11bgn ESSID:off/any
Mode:Managed Access Point: Not-Associated Tx-Power=0 dBm
Retry long limit:7 RTS thr:off Fragment thr:off
Encryption key:off
Power Management:off
无线网卡为 wlan0
3. 激活网卡
ifconfig wlan0 up
因为我的网卡必需要先激活才能扫描，否则下一步scan会出现错误：wlan0 Interface doesn't support scanning.
4. 扫描网络
iwlist wlan0 scan
wlan0 Scan completed :
Cell 01 - Address: 54:E6:FC:22:E1:D2
Channel:1
Frequency:2.412 GHz (Channel 1)
Quality=53/70 Signal level=-57 dBm
Encryption key:on
ESSID:"TP-LINK_22E1D2"
Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
9 Mb/s; 12 Mb/s; 18 Mb/s
Bit Rates:24 Mb/s; 36 Mb/s; 48 Mb/s; 54 Mb/s
Mode:Master
Extra:tsf=000000292a41bd80
Extra: Last beacon: 960ms ago
IE: Unknown: 000E54502D4C494E4B5F323245314432
IE: Unknown: 010882848B960C121824
IE: Unknown: 030101
IE: IEEE 802.11i/WPA2 Version 1
Group Cipher : CCMP
Pairwise Ciphers (1) : CCMP
Authentication Suites (1) : PSK
IE: WPA Version 1
Group Cipher : CCMP
Pairwise Ciphers (1) : CCMP
Authentication Suites (1) : PSK
发现WPA2-PSK/WPA-PSK 加密网络 TP-LINK_22E1D2，因为加密方式为 WPA-PSK 所以得用 wpa_supplicant 而不能使用 iwconfig wlan0 key xxx 形式，iwconfig key方式适用于WEP。
5. 配置 wpa_supplicant
新建文件 /etc/my_wpa_supplicant.conf
ctrl_interface=/var/run/wpa_supplicant
network={
ssid="TP-LINK_22E1D2"
psk="密码"
}
因为全部使用默认配置，所以配置文件非常简单。
6. 连接wlan0到网络，并以daemon方式运行
wpa_supplicant -B -i wlan0 -c /etc/my_wpa_supplicant.conf
-B Background 在后台以daemon 运行
-i interface
-c 配置文件
7. 设置IP地址
ifconfig wlan0 192.168.1.131
ifconfig 查看状态
wlan0 Link encap:Ethernet HWaddr 54:E6:FC:03:0D:6B
inet addr:192.168.1.131 Bcast:192.168.1.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:95 errors:0 dropped:0 overruns:0 frame:0
TX packets:4 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:32434 (31.6 Kb) TX bytes:576 (576.0 b)
8. 加入网关到路由
我的网关的是192.168.1.1，添加通过wlan0访问的网关
route add default gw 192.168.1.1 dev wlan0
查看状态
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 * 255.255.255.0 U 0 0 0 wlan0
default 192.168.1.1 0.0.0.0 UG 0 0 0 wlan0
9. 设置完毕。
以后上线只需运行以下命令即可
wpa_supplicant -B -i wlan0 -c /etc/my_wpa_supplicant.conf
ifconfig wlan0 192.168.1.131
route add default gw 192.168.1.1 dev wlan0
10. 相关命令
关闭连接
wpa_cli terminate
连接状态
wpa_cli status