突然之间，我的笔记本电脑（HP Pavilion dv7，运行 Ubuntu 12.04，内核 3.2.0-64-generic）上的内置 Wifi 接口无法出现。
# ifconfig wlan0
wlan0 Link encap:Ethernet HWaddr 40:25:c2:d9:fb:8c
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
# iwconfig wlan0
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
“dmesg”命令显示
ADDRCONF(NETDEV_UP): wlan0: link is not ready
以下是一些内核模块
# lsmod | grep iw
iwlwifi 381794 0
mac80211 543880 1 iwlwifi
cfg80211 210370 2 iwlwifi,mac80211
compat 13447 7 iwlwifi,mac80211,cfg80211,bnep,rfcomm,bluetooth,usbnet
我正在运行“网络管理器”，图标在系统托盘中，但它没有显示任何无线网络，即使它距离 WiFi 路由器只有几英尺（我的手机可以正常与 WiFi 路由器通信）。
命令“iwlist wlan0 scan”显示 ESSID 列表（包括我的 WiFi 路由器）。
我尝试了以下操作，但没有帮助。 sudo ifdown wlan0 sudo ifup wlan0
重新启动笔记本电脑也无济于事。
任何帮助将不胜感激！
dmesg 的一部分
[ 5534.540251] iwlwifi 0000:07:00.0: PCI INT A disabled
[ 5544.897099] cfg80211: Calling CRDA to update world regulatory domain
[ 5544.907411] cfg80211: World regulatory domain updated:
[ 5544.907414] cfg80211: (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp)
[ 5544.907416] cfg80211: (2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
[ 5544.907418] cfg80211: (2457000 KHz - 2482000 KHz @ 20000 KHz), (300 mBi, 2000 mBm)
[ 5544.907419] cfg80211: (2474000 KHz - 2494000 KHz @ 20000 KHz), (300 mBi, 2000 mBm)
[ 5544.907421] cfg80211: (5170000 KHz - 5250000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
[ 5544.907423] cfg80211: (5735000 KHz - 5835000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
[ 5544.910517] iwlwifi: Intel(R) Wireless WiFi Link AGN driver for Linux, in-tree:
[ 5544.910519] iwlwifi: Copyright(c) 2003-2012 Intel Corporation
[ 5544.910605] iwlwifi 0000:07:00.0: PCI INT A -> GSI 17 (level, low) -> IRQ 17
[ 5544.910651] iwlwifi 0000:07:00.0: setting latency timer to 64
[ 5544.910692] iwlwifi 0000:07:00.0: pci_resource_len = 0x00002000
[ 5544.910694] iwlwifi 0000:07:00.0: pci_resource_base = ffffc90012614000
[ 5544.910695] iwlwifi 0000:07:00.0: HW Revision ID = 0x67
[ 5544.910856] iwlwifi 0000:07:00.0: irq 53 for MSI/MSI-X
[ 5544.915028] iwlwifi 0000:07:00.0: loaded firmware version 41.28.5.1 build 33926
[ 5544.915490] iwlwifi 0000:07:00.0: CONFIG_IWLWIFI_DEBUG disabled
[ 5544.915500] iwlwifi 0000:07:00.0: CONFIG_IWLWIFI_DEBUGFS enabled
[ 5544.915508] iwlwifi 0000:07:00.0: CONFIG_IWLWIFI_DEVICE_TRACING enabled
[ 5544.915515] iwlwifi 0000:07:00.0: CONFIG_IWLWIFI_DEVICE_TESTMODE disabled
[ 5544.915523] iwlwifi 0000:07:00.0: CONFIG_IWLWIFI_P2P enabled
[ 5544.915531] iwlwifi 0000:07:00.0: Detected Intel(R) Centrino(R) Wireless-N + WiMAX 6150 BGN, REV=0x84
[ 5544.915733] iwlwifi 0000:07:00.0: L1 Enabled; Disabling L0S
[ 5544.926407] iwlwifi 0000:07:00.0: device EEPROM VER=0x557, CALIB=0x6
[ 5544.926411] iwlwifi 0000:07:00.0: Device SKU: 0x150
[ 5544.926414] iwlwifi 0000:07:00.0: Valid Tx ant: 0x1, Valid Rx ant: 0x3
[ 5544.926433] iwlwifi 0000:07:00.0: Tunable channels: 13 802.11bg, 0 802.11a channels
[ 5544.926586] Registered led device: phy0-led
[ 5544.926621] cfg80211: Ignoring regulatory request Set by core since the driver uses its own custom regulatory domain
[ 5544.926785] ieee80211 phy0: Selected rate control algorithm 'iwl-agn-rs'
答案1
尝试编辑/etc/network/interfaces：
auto wlan0 iface wlan0 inet dhcp wireless-essid [ESSID] wpa-psk password`
如果这是您的网络管理员的问题，这应该会有所帮助。