我的联想 T420 上有一块英特尔公司 Centrino Advanced-N 6205 [Taylor Peak] 无线网卡（在lspci03:00.0 网络控制器下找到：），它有 win7/Ubuntu 16.04 LTS 双启动。目前，WLAN 在我的 Ubuntu16.04 操作系统上无法工作，而 WLAN 在 Windows 下可以完美运行，因此我排除了卡损坏的问题。具体问题是，如果我单击 Internet 符号（右上角，显示蓝牙的标志的左侧以及我正在使用的国家/地区键盘布局），我找不到笔记本电脑周围的任何 WIFI，而在 win7 下我可以毫无问题地找到它们。我断定一定是出了什么问题，因为我记得几年前使用过一个 Ubuntu 系统，它也能自动找到 WIFI 连接。
我发现笔记本电脑显示器底部的小型 WLAN 灯经常不亮，因此我得出结论，卡未激活。
ifconfig已交付（未插入以太网）：
enp0s25 Link encap:Ethernet HWaddr 00:21:cc:6c:57:c4
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:14951 errors:0 dropped:0 overruns:0 frame:0
TX packets:13581 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:9938054 (9.9 MB) TX bytes:1650168 (1.6 MB)
Interrupt:20 Memory:f2600000-f2620000
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:9376 errors:0 dropped:0 overruns:0 frame:0
TX packets:9376 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:1040510 (1.0 MB) TX bytes:1040510 (1.0 MB)
我事先知道 wlp3s0 接口应该已启动。所以我检查了它是否已启动iwlconfig（未插入以太网）：
enp0s25 no wireless extensions.
lo no wireless extensions.
wlp3s0 IEEE 802.11abgn ESSID:off/any
Mode:Managed Access Point: Not-Associated Tx-Power=15 dBm
Retry short limit:7 RTS thr:off Fragment thr:off
Power Management:off
我使用以下方法激活它：
sudo ifconfig wlp3s0 up
ifconfig然后显示与之前相同的内容，但另外显示：
wlp3s0 Link encap:Ethernet HWaddr 08:11:96:25:81:e0
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)
我检查过nmcli-g：
STATE CONNECTIVITY WIFI-HW WIFI WWAN-HW WWAN
disconnected none enabled enabled enabled enabled
从我发现的所有内容来看，该卡应该受我当前内核的支持（通过以下方式找到uname -a：Linux isofruit-ThinkPad-T420 4.4.0-22-generic #40-Ubuntu SMP Thu May 12 22:03:46 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux），这意味着驱动程序应该在那里。
$ lsmod | grep iwlagn
什么都没返回。iwlagn 和 dmesg 上的 Modprobe 给出以下信息：
$ sudo modprobe iwlagn
modprobe: FATAL: Module iwlagn not found in directory /lib/modules/4.4.0-22-generic
$ dmesg | grep -i iwl
> [ 7.061277] iwlwifi 0000:03:00.0: can't disable ASPM; OS doesn't have ASPM control
[ 7.066591] iwlwifi 0000:03:00.0: loaded firmware version 18.168.6.1 op_mode iwldvm
[ 7.103547] iwlwifi 0000:03:00.0: CONFIG_IWLWIFI_DEBUG disabled
[ 7.103551] iwlwifi 0000:03:00.0: CONFIG_IWLWIFI_DEBUGFS enabled
[ 7.103553] iwlwifi 0000:03:00.0: CONFIG_IWLWIFI_DEVICE_TRACING enabled
[ 7.103556] iwlwifi 0000:03:00.0: Detected Intel(R) Centrino(R) Advanced-N 6205 AGN, REV=0xB0
[ 7.103655] iwlwifi 0000:03:00.0: L1 Enabled - LTR Disabled
[ 7.135783] ieee80211 phy0: Selected rate control algorithm 'iwl-agn-rs'
[ 7.446974] iwlwifi 0000:03:00.0 wlp3s0: renamed from wlan0
[ 1197.242686] iwlwifi 0000:03:00.0: L1 Enabled - LTR Disabled
[ 1197.242927] iwlwifi 0000:03:00.0: L1 Enabled - LTR Disabled
[ 1197.243020] iwlwifi 0000:03:00.0: Radio type=0x1-0x2-0x0
[ 1197.525577] iwlwifi 0000:03:00.0: L1 Enabled - LTR Disabled
[ 1197.525810] iwlwifi 0000:03:00.0: L1 Enabled - LTR Disabled
[ 1197.525901] iwlwifi 0000:03:00.0: Radio type=0x1-0x2-0x0
[ 1456.897367] iwlwifi 0000:03:00.0: L1 Enabled - LTR Disabled
[ 1456.897637] iwlwifi 0000:03:00.0: L1 Enabled - LTR Disabled
[ 1456.897739] iwlwifi 0000:03:00.0: Radio type=0x1-0x2-0x0
[ 1457.179161] iwlwifi 0000:03:00.0: L1 Enabled - LTR Disabled
[ 1457.179419] iwlwifi 0000:03:00.0: L1 Enabled - LTR Disabled
[ 1457.179591] iwlwifi 0000:03:00.0: Radio type=0x1-0x2-0x0
[ 3024.765374] iwlwifi 0000:03:00.0: L1 Enabled - LTR Disabled
[ 3024.765672] iwlwifi 0000:03:00.0: L1 Enabled - LTR Disabled
[ 3024.765777] iwlwifi 0000:03:00.0: Radio type=0x1-0x2-0x0
[ 3025.037457] iwlwifi 0000:03:00.0: L1 Enabled - LTR Disabled
[ 3025.037730] iwlwifi 0000:03:00.0: L1 Enabled - LTR Disabled
[ 3025.037833] iwlwifi 0000:03:00.0: Radio type=0x1-0x2-0x0
[ 3162.486526] iwlwifi 0000:03:00.0: L1 Enabled - LTR Disabled
[ 3162.486837] iwlwifi 0000:03:00.0: L1 Enabled - LTR Disabled
[ 3162.486943] iwlwifi 0000:03:00.0: Radio type=0x1-0x2-0x0
[ 3162.768909] iwlwifi 0000:03:00.0: L1 Enabled - LTR Disabled
[ 3162.769163] iwlwifi 0000:03:00.0: L1 Enabled - LTR Disabled
[ 3162.769266] iwlwifi 0000:03:00.0: Radio type=0x1-0x2-0x0
进一步sudo lshw -C network回报：
*-network
description: Ethernet interface
product: 82579LM Gigabit Network Connection
vendor: Intel Corporation
physical id: 19
bus info: pci@0000:00:19.0
logical name: enp0s25
version: 04
serial: 00:21:cc:6c:57:c4
capacity: 1Gbit/s
width: 32 bits
clock: 33MHz
capabilities: pm msi bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=e1000e driverversion=3.2.6-k firmware=0.13-3 latency=0 link=no multicast=yes port=twisted pair
resources: irq:25 memory:f2600000-f261ffff memory:f262b000-f262bfff ioport:5080(size=32)
*-network
description: Wireless interface
product: Centrino Advanced-N 6205 [Taylor Peak]
vendor: Intel Corporation
physical id: 0
bus info: pci@0000:03:00.0
logical name: wlp3s0
version: 34
serial: 08:11:96:25:81:e0
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
configuration: broadcast=yes driver=iwlwifi driverversion=4.4.0-22-generic firmware=18.168.6.1 latency=0 link=no multicast=yes wireless=IEEE 802.11abgn
resources: irq:28 memory:f2500000-f2501fff
扫描网络返回：
$ iwlist scan
enp0s25 Interface doesn't support scanning.
lo Interface doesn't support scanning.
wlp3s0 No scan results
sudo rfkill 交付：
$sudo rfkill list
0: tpacpi_bluetooth_sw: Bluetooth
Soft blocked: no
Hard blocked: no
2: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no
3: hci0: Bluetooth
Soft blocked: yes
Hard blocked: no
遗憾的是，我找不到任何解决方案，因为其他人要么遇到了硬件问题，要么根本找不到解决方案。以上所有数据都是在未插入以太网电缆时获取的。
提前感谢大家的评论/回复！谢谢，Isofruit