CentOS 5 安装和配置无线网卡指南

1.下载无线网卡驱动程序；
2.安装无线网卡驱动程序；
3.配置无线拨号配置文件；
4.注意事项和备注。

1， 到http://snapshots.madwifi-project.org下载最新的madwifi- hal-0.10.5.6文件,如madwifi-hal-0.10.5.6-r4016-20090429.tar.gz；
2，解压后.gz文件后用make && make install编译安装，最好从新启动一下系统；
3，确保下列类似信息的存在：[simonsun@magic ~]$ /sbin/lspci | grep Ethernet
02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 02)
06:00.0 Ethernet controller: Atheros Communications Inc. AR242x 802.11abg Wireless PCI Express Adapter (rev 01)
[simonsun@magic ~]$ dmesg | grep "HAL"
[simonsun@magic ~]$ /sbin/lsmod | grep ath
dm_multipath           24013  0
scsi_dh                11713  1 dm_multipath
ath_rate_sample        16256  1
ath_pci               230844  0
wlan                  203760  5 wlan_tkip,wlan_scan_sta,ath_rate_sample,ath_pci
ath_hal               305632  3 ath_rate_sample,ath_pci
dm_mod                 62201  11 dm_multipath,dm_raid45,dm_snapshot,dm_zero,dm_mirror,dm_log
[simonsun@magic ~]$  /sbin/iwlist
Usage: iwlist [interface] scanning
              [interface] frequency
              [interface] channel
              [interface] bitrate
              [interface] rate
              [interface] encryption
              [interface] key
              [interface] power
              [interface] txpower
              [interface] retry
              [interface] ap
              [interface] accesspoints
              [interface] peers
              [interface] event
[simonsun@magic ~]$
即：网卡是否检测到、网卡驱动是否被系统识别、是否有错误信息等。
然后开始搜寻无线网络，如

[simonsun@magic ~]$ /sbin/iwlist ath0 scan
ath0      Scan completed :
          Cell 01 - Address: 08:10:74:2B:C3:90
                    ESSID:"NETCORE"
                    Mode:Master
                    Frequency:2.437 GHz (Channel 6)
                    Quality=46/70  Signal level=-49 dBm  Noise level=-95 dBm
                    Encryption key:on
                    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; 24 Mb/s; 36 Mb/s
                              48 Mb/s; 54 Mb/s
                    Extra:bcn_int=100
                    IE: WPA Version 1
                        Group Cipher : TKIP
                        Pairwise Ciphers (1) : TKIP
                        Authentication Suites (1) : PSK 
          Cell 02 - Address: 00:22:B0:91:5B:D1
                    ESSID:"dlink-starsing"
                    Mode:Master
                    Frequency:2.417 GHz (Channel 2)
                    Quality=23/70  Signal level=-72 dBm  Noise level=-95 dBm
                    Encryption key:on
                    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; 24 Mb/s; 36 Mb/s
                              48 Mb/s; 54 Mb/s
                    Extra:bcn_int=100
                    IE: IEEE 802.11i/WPA2 Version 1
                        Group Cipher : TKIP
                        Pairwise Ciphers (2) : CCMP TKIP
                        Authentication Suites (1) : PSK 
                    IE: WPA Version 1
                        Group Cipher : TKIP
                        Pairwise Ciphers (2) : CCMP TKIP
                        Authentication Suites (1) : PSK 
                    Extra:ath_ie=dd0900037f01010060ff7f
          Cell 03 - Address: 00:19:E0:AD:B1:5E
                    ESSID:"TP-LINK"
                    Mode:Master
                    Frequency:2.437 GHz (Channel 6)
                    Quality=17/70  Signal level=-78 dBm  Noise level=-95 dBm
                    Encryption key:on
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
                              12 Mb/s; 24 Mb/s; 36 Mb/s; 9 Mb/s; 18 Mb/s
                              48 Mb/s; 54 Mb/s
                    Extra:bcn_int=100
                    Extra:ath_ie=dd0900037f01010008ff7f
          Cell 04 - Address: 00:21:27:BA:63:A2
                    ESSID:"TP-LINK_BA63A0"
                    Mode:Master
                    Frequency:2.437 GHz (Channel 6)
                    Quality=12/70  Signal level=-83 dBm  Noise level=-95 dBm
                    Encryption key:off
                    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; 24 Mb/s; 36 Mb/s
                              48 Mb/s; 54 Mb/s
                    Extra:bcn_int=100
                    Extra:wme_ie=dd180050f2020101030003a4000027a4000042435e0062322f00
                    Extra:ath_ie=dd0900037f01010000ff7f
          Cell 05 - Address: 00:B0:0C:04:C4:D2
                    ESSID:"TENDA"
                    Mode:Master
                    Frequency:2.452 GHz (Channel 9)
                    Quality=15/70  Signal level=-80 dBm  Noise level=-95 dBm
                    Encryption key:on
                    Bit Rates:6 Mb/s; 9 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s
                              36 Mb/s; 48 Mb/s; 54 Mb/s
                    Extra:bcn_int=100
          Cell 06 - Address: 00:23:CD:36:D3:C4
                    ESSID:"TP-LINK_36D3C4"
                    Mode:Master
                    Frequency:2.437 GHz (Channel 6)
                    Quality=11/70  Signal level=-84 dBm  Noise level=-95 dBm
                    Encryption key:off
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
                              12 Mb/s; 24 Mb/s; 36 Mb/s; 9 Mb/s; 18 Mb/s
                              48 Mb/s; 54 Mb/s
                    Extra:bcn_int=100
                    Extra:ath_ie=dd0900037f01010008ff7f
          Cell 07 - Address: 00:B0:0C:03:B0:64
                    ESSID:"Tenda"
                    Mode:Master
                    Frequency:2.437 GHz (Channel 6)
                    Quality=17/70  Signal level=-78 dBm  Noise level=-95 dBm
                    Encryption key:on
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 9 Mb/s
                              18 Mb/s; 36 Mb/s; 54 Mb/s; 6 Mb/s; 12 Mb/s
                              24 Mb/s; 48 Mb/s
                    Extra:bcn_int=100
                    Extra:wme_ie=dd180050f2020101000003a4000027a4000042435e0062322f00
          Cell 08 - Address: 00:1B:11:8C:3B:8C
                    ESSID:"dlink"
                    Mode:Master
                    Frequency:2.462 GHz (Channel 11)
                    Quality=7/70  Signal level=-88 dBm  Noise level=-95 dBm
                    Encryption key:on
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
                              9 Mb/s; 12 Mb/s; 48 Mb/s; 18 Mb/s; 24 Mb/s
                              36 Mb/s; 54 Mb/s
                    Extra:bcn_int=100

根据实际情况编辑如下文件，或者通过system-config-network的图形化界面配置，
[simonsun@magic ~]$ sudo vim /etc/sysconfig/network-scripts/ifcfg-ath0
# Atheros Communications Inc. AR242x 802.11abg Wireless PCI Express Adapter
DEVICE=ath0
BOOTPROTO=none
ONBOOT=no
HWADDR=00:22:43:2d:ae:2b
NETMASK=255.255.255.0
DHCP_HOSTNAME=
IPADDR=192.168.0.152
DOMAIN=
TYPE=Wireless
ESSID=NETCORE
CHANNEL=
MODE=Managed
SECURITYMODE=off
RATE=auto
USERCTL=no
IPV6INIT=no
PEERDNS=yes
GATEWAY=192.168.0.1


配好会有：
[simonsun@magic ~]$ /sbin/iwconfig ath0
ath0      IEEE 802.11g  ESSID:"NETCORE"  Nickname:"magic.linux"
          Mode:Managed  Frequency:2.437 GHz  Access Point: 08:10:74:2B:C3:90  
          Bit Rate:48 Mb/s   Tx-Power:17 dBm   Sensitivity=1/1 
          Retry:off   RTS thr:off   Fragment thr:off
          Power Management:off
          Link Quality=48/70  Signal level=-48 dBm  Noise level=-96 dBm
          Rx invalid nwid:38122  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0


最后，激活配置好的无线网卡，
[simonsun@magic ~]$ sudo /sbin/ifconfig ath0 up
[simonsun@magic ~]$ sudo /sbin/ifup ath0
[simonsun@magic ~]$  /sbin/ifconfig ath0
ath0      Link encap:Ethernet  HWaddr 00:22:43:2D:AE:2B 
          inet addr:192.168.0.152  Bcast:192.168.0.255  Mask:255.255.255.0
          inet6 addr: fe80::222:43ff:fe2d:ae2b/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:106106 errors:0 dropped:0 overruns:0 frame.:0
          TX packets:30806 errors:1 dropped:1 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:140732082 (134.2 MiB)  TX bytes:1976717 (1.8 MiB)

[simonsun@magic ~]$ ping www.google.com
PING www-china.l.google.com (66.249.89.99) 56(84) bytes of data.
64 bytes from jp-in-f99.google.com (66.249.89.99): icmp_seq=1 ttl=246 time=67.1 ms
64 bytes from jp-in-f99.google.com (66.249.89.99): icmp_seq=2 ttl=246 time=65.3 ms
64 bytes from jp-in-f99.google.com (66.249.89.99): icmp_seq=3 ttl=246 time=66.4 ms
64 bytes from jp-in-f99.google.com (66.249.89.99): icmp_seq=4 ttl=246 time=65.8 ms

--- www-china.l.google.com ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3001ms
rtt min/avg/max/mdev = 65.352/66.205/67.137/0.714 ms
[simonsun@magic ~]$


4.注意事项，一般需要设置DNS，不要忘了；如果是根据mac地址限制网络使用的话，一定要将无线网卡的mac地址正确的添加到路由器；如果连接模式通过WPA-PSK进行加密登录的话，就需要用到wpa_supplicant:
[simonsun@magic ~]$ sudo yum install \*wpa\*

[simonsun@magic ~]$ /usr/sbin/wpa_passphrase NETCORE 123456781
network={
        ssid="NETCORE"
        #psk="123456781"
        psk=21135846dce955a6319561d7216a1407d1cb97b8fb339c05f8773a3f780d6663
}

[simonsun@magic ~]$ sudo vim /etc/wpa_supplicant/wpa_supplicant.conf
修改如下：
ctrl_interface=/var/run/wpa_supplicant
ctrl_interface_group=wheel

#network={
#       ssid="any"
#       key_mgmt=NONE
#}
network={
        ssid="NETCORE"
        #psk="123456781"
        psk=21135846dce955a6319561d7216a1407d1cb97b8fb339c05f8773a3f780d6663
}
[simonsun@magic ~]$ sudo vim /etc/sysconfig/wpa_supplicant
修改INTERFACES为前面装好驱动后识别的网卡，如ath0，我这里是：
# Use the flag "-i" before each of your interfaces, like so:
#  INTERFACES="-i eth1 -i wlan0"
INTERFACES="-i ath0"

# Use the flag "-D" before each driver, like so:
#  DRIVERS="-D wext"
DRIVERS="-D wext"

# Other arguments
#   -u   Enable the D-Bus interface (required for use with NetworkManager)
#   -f   Log to /var/log/wpa_supplicant.log
OTHER_ARGS="-u -f /var/log/wpa_supplicant.log"

，然后启动wpa服务，
[simonsun@magic ~]$ sudo /etc/rc.d/init.d/wpa_supplicant start
Starting wpa_supplicant: /etc/wpa_supplicant/wpa_supplicant[确定]-i ath0 -D wext -u -f /var/log/wpa_supplicant.log

，然后拨号，平时上网，只执行如下脚本即可
sudo /sbin/ifconfig ath0 up
sudo /sbin/ifdown ath0
sudo /sbin/ifup ath0
sudo /etc/rc.d/init.d/wpa_supplicant restart
sudo /etc/rc.d/init.d/iptables restart

参考连接：
http://wiki.centos.org/HowTos/Laptops/WirelessAR5007EG
http://hi.baidu.com/netred/blog/item/6d7f061f708b8ccfa786691e.html

BTW，特别鸣谢秦公子网络环境方面的帮助。

2009-06-22，如果系统内核升级了，必须重新编译一下驱动，再次配置。

2011-07-11，现在CentOS 6 系列能自动识别大部分无线网卡了，一般不用像上面那么费劲的配置了 :) .
备注：
如果SSID名字改了，须要重新修改无线网络配置里的无线设置的网络名称的指定的，同时必须 (千万别忘了）重新生成一下密码钥匙，即：用/usr/sbin/wpa_passphrase 新名字 新密码，然后再次拨号即可。
其实最合理的是，从新建一个无线拨号连接，当然也得重新生成一下密码钥匙，添加到/etc/wpa_supplicant/wpa_supplicant.conf里。

附最新的Windows的无线网卡驱动，关于Atheros Communications Inc. AR5XXX Wireless Windows下的驱动。