1. 需安装wpa_supplicant
https://wiki.archlinux.org/index.php/WPA_Supplicant_%28%E7%AE%80%E4%BD%93%E4%B8%AD%E6%96%87%29
2. 安装dhcpcd
要求关闭NetManager服务，常常出现如下错误：
ioctl[SIOCSIWSCAN]: Device or resource busy
dhclient eth1
wpa_passphrase iscas_internal jiubugaosuni | wpa_supplicant -B -i eth1 -c /dev/stdin