我經常在從筆記型電腦和桌上型電腦連接 WiFi 時遇到問題。兩台機器都運行 Ubuntu 14.04。
有時我無法連接到 wifi，唯一的解決方案似乎是重新啟動路由器。重新啟動或重新啟動網路管理員都沒有幫助。我還遇到了一個建議執行的解決方案sudo pkill -f wpa_supplicant，我已經認為該解決方案可以解決問題，但沒有，它又發生了。
該問題總是在重新啟動後或從掛起狀態喚醒後發生。一旦我重新啟動路由器，它通常可以解決（儘管有時也可能需要重新啟動機器）並且連接保持穩定。在使用 Windows、Mac OS 或 Android 的其他裝置上不會出現此問題。
以下是一次連線嘗試的日誌/var/log/syslog：
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> Auto-activating connection 'Bastians WLAN'.
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> Activation (wlan0) starting connection 'Bastians WLAN'
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> (wlan0): device state change: disconnected -> prepare (reason 'none') [30 40 0]
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> NetworkManager state is now CONNECTING
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) scheduled...
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) started...
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) scheduled...
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) complete.
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) starting...
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> (wlan0): device state change: prepare -> config (reason 'none') [40 50 0]
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> Activation (wlan0/wireless): access point 'Bastians WLAN' has security, but secrets are required.
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> (wlan0): device state change: config -> need-auth (reason 'none') [50 60 0]
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) complete.
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) scheduled...
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) started...
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> (wlan0): device state change: need-auth -> prepare (reason 'none') [60 40 0]
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) scheduled...
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) complete.
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) starting...
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> (wlan0): device state change: prepare -> config (reason 'none') [40 50 0]
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> Activation (wlan0/wireless): connection 'Bastians WLAN' has security, and secrets exist. No new secrets needed.
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> Config: added 'ssid' value 'Bastians WLAN'
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> Config: added 'scan_ssid' value '1'
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> Config: added 'key_mgmt' value 'WPA-PSK'
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> Config: added 'auth_alg' value 'OPEN'
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> Config: added 'psk' value '<omitted>'
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) complete.
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> Config: set interface ap_scan to 1
Apr 16 21:30:42 Karl2 NetworkManager[811]: <info> (wlan0): supplicant interface state: disconnected -> scanning
Apr 16 21:31:07 Karl2 NetworkManager[811]: <warn> Activation (wlan0/wireless): association took too long, failing activation.
Apr 16 21:31:07 Karl2 NetworkManager[811]: <info> (wlan0): device state change: config -> failed (reason 'SSID not found') [50 120 53]
Apr 16 21:31:07 Karl2 NetworkManager[811]: <info> NetworkManager state is now DISCONNECTED
Apr 16 21:31:07 Karl2 NetworkManager[811]: <info> Marking connection 'Bastians WLAN' invalid.
Apr 16 21:31:07 Karl2 NetworkManager[811]: <warn> Activation (wlan0) failed for connection 'Bastians WLAN'
Apr 16 21:31:07 Karl2 NetworkManager[811]: <info> (wlan0): device state change: failed -> disconnected (reason 'none') [120 30 0]
Apr 16 21:31:07 Karl2 NetworkManager[811]: <info> (wlan0): deactivating device (reason 'none') [0]
Apr 16 21:31:07 Karl2 NetworkManager[811]: <info> (wlan0): supplicant interface state: scanning -> disconnected
Apr 16 21:31:07 Karl2 NetworkManager[811]: <warn> Couldn't disconnect supplicant interface: This interface is not connected.
答案1
我以前也遇到類似的問題，我建議安裝wicd網路管理器，可以找到安裝說明這裡