我在我的新笔记本电脑 Lenovo Thinkpad E540 上安装了 ubuntu 14.04，
我连接到了 wifi 网络，但过了一会儿，我丢失了连接，我尝试重新连接，但无法再次连接到任何 wifi 网络。为了再次连接，我必须重新启动计算机。
这是我的 dmesg 代码的一部分：
[ 618.444235] wlan0: authenticate with f8:1a:67:b5:da:63
[ 618.464150] wlan0: send auth to f8:1a:67:b5:da:63 (try 1/3)
[ 618.465700] wlan0: authenticated
[ 618.467617] wlan0: associate with f8:1a:67:b5:da:63 (try 1/3)
[ 618.471473] wlan0: RX AssocResp from f8:1a:67:b5:da:63 (capab=0x411 status=0 aid=2)
[ 618.471683] wlan0: associated
[ 618.471735] cfg80211: Calling CRDA for country: US
[ 618.473575] cfg80211: Regulatory domain changed to country: US
[ 618.473578] cfg80211: DFS Master region: unset
[ 618.473579] cfg80211: (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp), (dfs_cac_time)
[ 618.473581] cfg80211: (2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2700 mBm), (N/A)
[ 618.473583] cfg80211: (5170000 KHz - 5250000 KHz @ 40000 KHz), (300 mBi, 1700 mBm), (N/A)
[ 618.473584] cfg80211: (5250000 KHz - 5330000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (0 s)
[ 618.473585] cfg80211: (5490000 KHz - 5600000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (0 s)
[ 618.473587] cfg80211: (5650000 KHz - 5710000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (0 s)
[ 618.473588] cfg80211: (5735000 KHz - 5835000 KHz @ 40000 KHz), (300 mBi, 3000 mBm), (N/A)
[ 618.473589] cfg80211: (57240000 KHz - 63720000 KHz @ 2160000 KHz), (N/A, 4000 mBm), (N/A)
[ 643.634049] wlan0: Connection to AP f8:1a:67:b5:da:63 lost
[ 643.666952] cfg80211: Calling CRDA to update world regulatory domain
[ 643.669050] cfg80211: World regulatory domain updated:
[ 643.669053] cfg80211: DFS Master region: unset
[ 643.669054] cfg80211: (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp), (dfs_cac_time)
[ 643.669056] cfg80211: (2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (N/A)
[ 643.669058] cfg80211: (2457000 KHz - 2482000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (N/A)
[ 643.669060] cfg80211: (2474000 KHz - 2494000 KHz @ 20000 KHz), (300 mBi, 2000 mBm), (N/A)
[ 643.669061] cfg80211: (5170000 KHz - 5250000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (N/A)
[ 643.669062] cfg80211: (5735000 KHz - 5835000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (N/A)
[ 645.069564] wlan0: authenticate with f8:1a:67:b5:da:63
[ 645.089661] wlan0: send auth to f8:1a:67:b5:da:63 (try 1/3)
[ 645.091299] wlan0: authenticated
[ 645.093193] wlan0: associate with f8:1a:67:b5:da:63 (try 1/3)
[ 645.098035] wlan0: RX AssocResp from f8:1a:67:b5:da:63 (capab=0x411 status=0 aid=2)
[ 645.098228] wlan0: associated
[ 645.098291] cfg80211: Calling CRDA for country: US
[ 645.100131] cfg80211: Regulatory domain changed to country: US
[ 645.100133] cfg80211: DFS Master region: unset
[ 645.100134] cfg80211: (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp), (dfs_cac_time)
[ 645.100137] cfg80211: (2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2700 mBm), (N/A)
[ 645.100138] cfg80211: (5170000 KHz - 5250000 KHz @ 40000 KHz), (300 mBi, 1700 mBm), (N/A)
[ 645.100140] cfg80211: (5250000 KHz - 5330000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (0 s)
[ 645.100141] cfg80211: (5490000 KHz - 5600000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (0 s)
[ 645.100142] cfg80211: (5650000 KHz - 5710000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (0 s)
[ 645.100144] cfg80211: (5735000 KHz - 5835000 KHz @ 40000 KHz), (300 mBi, 3000 mBm), (N/A)
[ 645.100145] cfg80211: (57240000 KHz - 63720000 KHz @ 2160000 KHz), (N/A, 4000 mBm), (N/A)
[ 726.303619] wlan0: Connection to AP f8:1a:67:b5:da:63 lost
[ 726.352482] cfg80211: Calling CRDA to update world regulatory domain
[ 726.354514] cfg80211: World regulatory domain updated:
[ 726.354517] cfg80211: DFS Master region: unset
[ 726.354518] cfg80211: (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp), (dfs_cac_time)
[ 726.354520] cfg80211: (2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (N/A)
[ 726.354522] cfg80211: (2457000 KHz - 2482000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (N/A)
[ 726.354523] cfg80211: (2474000 KHz - 2494000 KHz @ 20000 KHz), (300 mBi, 2000 mBm), (N/A)
[ 726.354524] cfg80211: (5170000 KHz - 5250000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (N/A)
[ 726.354526] cfg80211: (5735000 KHz - 5835000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (N/A)
[ 727.755050] wlan0: authenticate with f8:1a:67:b5:da:63
[ 727.775175] wlan0: send auth to f8:1a:67:b5:da:63 (try 1/3)
[ 727.776824] wlan0: authenticated
[ 727.778713] wlan0: associate with f8:1a:67:b5:da:63 (try 1/3)
[ 727.782440] wlan0: RX AssocResp from f8:1a:67:b5:da:63 (capab=0x411 status=0 aid=2)
[ 727.782642] wlan0: associated
[ 727.782693] cfg80211: Calling CRDA for country: US
[ 727.784431] cfg80211: Regulatory domain changed to country: US
[ 727.784433] cfg80211: DFS Master region: unset
[ 727.784434] cfg80211: (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp), (dfs_cac_time)
[ 727.784435] cfg80211: (2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2700 mBm), (N/A)
[ 727.784437] cfg80211: (5170000 KHz - 5250000 KHz @ 40000 KHz), (300 mBi, 1700 mBm), (N/A)
[ 727.784438] cfg80211: (5250000 KHz - 5330000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (0 s)
[ 727.784439] cfg80211: (5490000 KHz - 5600000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (0 s)
[ 727.784439] cfg80211: (5650000 KHz - 5710000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (0 s)
[ 727.784440] cfg80211: (5735000 KHz - 5835000 KHz @ 40000 KHz), (300 mBi, 3000 mBm), (N/A)
[ 727.784441] cfg80211: (57240000 KHz - 63720000 KHz @ 2160000 KHz), (N/A, 4000 mBm), (N/A)
[12208.927155] wlan0: deauthenticating from f8:1a:67:b5:da:63 by local choice (Reason: 3=DEAUTH_LEAVING)
[12218.549245] cfg80211: Calling CRDA to update world regulatory domain
[12218.551729] cfg80211: World regulatory domain updated:
[12218.551734] cfg80211: DFS Master region: unset
[12218.551735] cfg80211: (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp), (dfs_cac_time)
[12218.551738] cfg80211: (2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (N/A)
[12218.551741] cfg80211: (2457000 KHz - 2482000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (N/A)
[12218.551743] cfg80211: (2474000 KHz - 2494000 KHz @ 20000 KHz), (300 mBi, 2000 mBm), (N/A)
[12218.551745] cfg80211: (5170000 KHz - 5250000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (N/A)
[12218.551746] cfg80211: (5735000 KHz - 5835000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (N/A)
以下是我的 iwconfig 输出：
eth0 no wireless extensions.
wlan0 IEEE 802.11bgn ESSID:off/any
Mode:Managed Access Point: Not-Associated Tx-Power=20 dBm
Retry short limit:7 RTS thr=2347 B Fragment thr:off
Power Management:off
lo no wireless extensions.
我该如何修复它？我现在只能通过有线连接连接到网络 :(
你能帮我修复它吗？
答案1
此问题已被多次报告。下面列出了一些解决方案。
禁用 802.11N
在路由器中：更改802.11bgn为802.11bg。
在驱动程序中：取决于您的 WiFi 卡（但以上可能就足够了）。
加密
如果有该选项，请将路由器 WEP 加密更改为 WPA2 (CCMP)(AES) 而不是 (TKIP)。
路由器通道
将路由器中的无线频道设置为1或11，然后保存路由器配置并重新启动。
禁用 IPV6
在屏幕右上角的网络管理器中，单击编辑连接->无线选项卡，并将 IPV6 设置为忽略。
答案2
您的日志显示
根据本地选择从 f8:1a:67:b5:da:63 取消身份验证（原因：3=DEAUTH_LEAVING）
这意味着您的无线软件故意选择断开与接入点的连接。这很可能是您的客户端上的配置问题或软件冲突。
建议包括错误配置的请求者软件，或让多个应用程序同时尝试管理无线：
https://bbs.archlinux.org/viewtopic.php?id=163575
CRDA 数据设置不正确：
http://ubuntuforums.org/showthread.php?t=2259037
或者 Ubuntu 14.04 上有问题的驱动程序：
http://ubuntuforums.org/showthread.php?t=2198221&page=3
但是，由于您没有运行建议的无线信息脚本，因此很难知道。特别是，您没有指定正在使用的无线卡或驱动程序，但最后一个链接指的是联想 T440s，它可能有类似的硬件。
答案3
我看到过类似的问题，结果发现是几年前安装的旧 modprobe 配置文件（位于 /etc/modprobe.d 中）导致的。具体来说，它为cfg80211（WiFi 堆栈模块）指定了一个选项options cfg80211 ieee80211_regdom="EU"
注释/删除该选项并重新启动后，问题已修复。因此，请检查您的 modprobe.d 文件是否包含 cfg80211 的配置选项，然后尝试注释/删除它们。
另外，检查是否REGDOMAIN已设置也可能会有所帮助/etc/default/crda。有关更多详细信息，请参阅Linux 无线监管信息。