wifi--wpa_supplicant

Linux命令行连接wifi--wpa_supplicant

https://wiki.gentoo.org/wiki/Handbook:AMD64/Networking/Wireless

以CentOS7为例:
先启用无线网卡再扫描wifi信号
root@jlive:~#ip link set wlp3s0 up
root@jlive:~#iw dev wlp3s0 scan|grep wifi

A.WPA/WPA2加密
root@jlive:~#vim /etc/sysconfig/wpa_supplicant
network={
        ssid="wifi"
        psk="foo.123"
        priority=1
}
root@jlive:~#wpa_supplicant -i wlp3s0 -c /etc/sysconfig/wpa_supplicant
Successfully initialized wpa_supplicant
wlp3s0: Trying to associate with ec:26:ca:67:0b:fe (SSID='rukawa' freq=2437 MHz)
ioctl[SIOCSIWFREQ]: Device or resource busy
wlp3s0: Association request to the driver failed
wlp3s0: Associated with ec:26:ca:67:0b:fe
wlp3s0: WPA: Key negotiation completed with ec:26:ca:67:0b:fe [PTK=CCMP GTK=CCMP]
wlp3s0: CTRL-EVENT-CONNECTED - Connection to ec:26:ca:67:0b:fe completed [id=0 id_str=]
看到这个提示，应该感到非常兴奋，成功连接
root@jlive:~#ifconfig wlp3s0
wlp3s0: flags=4163  mtu 1500
        inet6 fe80::466d:57ff:feb3:a7e5  prefixlen 64  scopeid 0x20
        ether 44:6d:57:b3:a7:e5  txqueuelen 1000  (Ethernet)
        RX packets 2  bytes 282 (282.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 10  bytes 1096 (1.0 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
再看下是否拿到IP，发现没有，所以还差一步，主动发起DHCP请求地址
root@jlive:~#dhclient wlp3s0
root@jlive:~#ifconfig wlp3s0
wlp3s0: flags=4163  mtu 1500
        inet 192.168.100.108  netmask 255.255.255.0  broadcast 192.168.100.255
        inet6 fe80::466d:57ff:feb3:a7e5  prefixlen 64  scopeid 0x20
        ether 44:6d:57:b3:a7:e5  txqueuelen 1000  (Ethernet)
        RX packets 2885  bytes 2092956 (1.9 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 2708  bytes 488745 (477.2 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

B.wep加密

https://wiki.gentoo.org/wiki/Handbook:AMD64/Installation/Networking

For most users, there are only two settings that might be important to change, the ESSID (aka wireless network name) or the WEP key. If the ESSID and Access Point address listed are already those of the environment's access point and the environment is not not using WEP, then the wireless configuration is already working.

To change the ESSID, or add a WEP key, issue the following commands.

• To set the network name to GentooNode:

root #iwconfig eth0 essid GentooNode

• To set a hex WEP key:

root #iwconfig eth0 key 1234123412341234abcd

To set an ASCII WEP key, prefix the key with s::

root #iwconfig eth0 key s:some-password

或者 

root #iwconfig eth0 key s:some-password

root@jlive:~#iw dev wlp3s0 connect "wifi名" key 0:密码
root@jlive:~#dhclient wlp3s0