askubuntu 上有几十个 wifi 问题；我尝试了其中几个的答案，但都没有用。
症状是我的 Wifi 网络确实出现在网络菜单中，但是当我尝试连接时，它只是不断要求我输入密码。
这是在 HP Envy dv7 笔记本上安装的新 Ubuntu 14.04n，该笔记本也装有 Windows 8。wifi 设备是 Intel Centrino Wireless-N 2230。我已经安装了“iwlwifi”驱动程序。
请告诉我您需要什么信息以及如何获取这些信息。
谢谢！
这是我尝试连接 Wifi 时的系统日志输出。第一个看起来像问题的地方是第 33 行；wlan0 在尝试“关联”时超时：
Dec 20 23:36:31 sunwukong dbus[680]: [system] Activating service name='org.freedesktop.nm_dispatcher' (using servicehelper)
Dec 20 23:36:31 sunwukong dbus[680]: [system] Successfully activated service 'org.freedesktop.nm_dispatcher'
Dec 20 23:37:07 sunwukong NetworkManager[832]: <info> Activation (wlan0) starting connection 'MyNetwork'
Dec 20 23:37:07 sunwukong NetworkManager[832]: <info> (wlan0): device state change: disconnected -> prepare (reason 'none') [30 40 0]
Dec 20 23:37:07 sunwukong NetworkManager[832]: <info> NetworkManager state is now CONNECTING
Dec 20 23:37:07 sunwukong NetworkManager[832]: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) scheduled...
Dec 20 23:37:07 sunwukong NetworkManager[832]: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) started...
Dec 20 23:37:07 sunwukong NetworkManager[832]: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) scheduled...
Dec 20 23:37:07 sunwukong NetworkManager[832]: <info> Activation (wlan0) Stage 1 of 5 (Device Prepare) complete.
Dec 20 23:37:07 sunwukong NetworkManager[832]: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) starting...
Dec 20 23:37:07 sunwukong NetworkManager[832]: <info> (wlan0): device state change: prepare -> config (reason 'none') [40 50 0]
Dec 20 23:37:07 sunwukong NetworkManager[832]: <info> Activation (wlan0/wireless): connection 'MyNetwork' has security, and secrets exist. No new secrets needed.
Dec 20 23:37:07 sunwukong NetworkManager[832]: <info> Config: added 'ssid' value 'MyNetwork'
Dec 20 23:37:07 sunwukong NetworkManager[832]: <info> Config: added 'scan_ssid' value '1'
Dec 20 23:37:07 sunwukong NetworkManager[832]: <info> Config: added 'key_mgmt' value 'WPA-PSK'
Dec 20 23:37:07 sunwukong NetworkManager[832]: <info> Config: added 'auth_alg' value 'OPEN'
Dec 20 23:37:07 sunwukong NetworkManager[832]: <info> Config: added 'psk' value '<omitted>'
Dec 20 23:37:07 sunwukong NetworkManager[832]: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) complete.
Dec 20 23:37:07 sunwukong NetworkManager[832]: <info> Config: set interface ap_scan to 1
Dec 20 23:37:07 sunwukong wpa_supplicant[851]: message repeated 7 times: [ wlan0: CTRL-EVENT-SCAN-STARTED ]
Dec 20 23:37:07 sunwukong wpa_supplicant[851]: wlan0: SME: Trying to authenticate with XX:XX:XX:XX:XX (SSID='MyNetwork' freq=2462 MHz)
Dec 20 23:37:07 sunwukong kernel: [ 361.132118] wlan0: authenticate with XX:XX:XX:XX:XX
Dec 20 23:37:07 sunwukong NetworkManager[832]: <info> (wlan0): supplicant interface state: inactive -> authenticating
Dec 20 23:37:07 sunwukong kernel: [ 361.137921] wlan0: send auth to XX:XX:XX:XX:XX (try 1/3)
Dec 20 23:37:07 sunwukong kernel: [ 361.140378] wlan0: authenticated
Dec 20 23:37:07 sunwukong wpa_supplicant[851]: wlan0: Trying to associate with XX:XX:XX:XX:XX (SSID='MyNetwork' freq=2462 MHz)
Dec 20 23:37:07 sunwukong kernel: [ 361.140586] iwlwifi 0000:04:00.0 wlan0: disabling HT as WMM/QoS is not supported by the AP
Dec 20 23:37:07 sunwukong kernel: [ 361.140590] iwlwifi 0000:04:00.0 wlan0: disabling VHT as WMM/QoS is not supported by the AP
Dec 20 23:37:07 sunwukong kernel: [ 361.144383] wlan0: associate with XX:XX:XX:XX:XX (try 1/3)
Dec 20 23:37:07 sunwukong NetworkManager[832]: <info> (wlan0): supplicant interface state: authenticating -> associating
Dec 20 23:37:08 sunwukong kernel: [ 361.248520] wlan0: associate with XX:XX:XX:XX:XX (try 2/3)
Dec 20 23:37:08 sunwukong kernel: [ 361.356557] wlan0: associate with XX:XX:XX:XX:XX (try 3/3)
Dec 20 23:37:08 sunwukong kernel: [ 361.460627] wlan0: association with XX:XX:XX:XX:XX timed out
Dec 20 23:37:08 sunwukong NetworkManager[832]: <info> (wlan0): supplicant interface state: associating -> disconnected
Dec 20 23:37:08 sunwukong wpa_supplicant[851]: wlan0: CTRL-EVENT-SCAN-STARTED
Dec 20 23:37:08 sunwukong NetworkManager[832]: <info> (wlan0): supplicant interface state: disconnected -> scanning
Dec 20 23:37:08 sunwukong wpa_supplicant[851]: wlan0: SME: Trying to authenticate with XX:XX:XX:XX:XX (SSID='MyNetwork' freq=2462 MHz)
Dec 20 23:37:08 sunwukong kernel: [ 362.019731] wlan0: authenticate with XX:XX:XX:XX:XX
Dec 20 23:37:08 sunwukong kernel: [ 362.023050] wlan0: send auth to XX:XX:XX:XX:XX (try 1/3)
Dec 20 23:37:08 sunwukong NetworkManager[832]: <info> (wlan0): supplicant interface state: scanning -> authenticating
Dec 20 23:37:08 sunwukong wpa_supplicant[851]: wlan0: Trying to associate with XX:XX:XX:XX:XX (SSID='MyNetwork' freq=2462 MHz)
Dec 20 23:37:08 sunwukong kernel: [ 362.025665] wlan0: authenticated
Dec 20 23:37:08 sunwukong kernel: [ 362.025906] iwlwifi 0000:04:00.0 wlan0: disabling HT as WMM/QoS is not supported by the AP
Dec 20 23:37:08 sunwukong kernel: [ 362.025914] iwlwifi 0000:04:00.0 wlan0: disabling VHT as WMM/QoS is not supported by the AP
Dec 20 23:37:08 sunwukong kernel: [ 362.028987] wlan0: associate with XX:XX:XX:XX:XX (try 1/3)
Dec 20 23:37:08 sunwukong NetworkManager[832]: <info> (wlan0): supplicant interface state: authenticating -> associating
Dec 20 23:37:08 sunwukong kernel: [ 362.133043] wlan0: associate with XX:XX:XX:XX:XX (try 2/3)
Dec 20 23:37:09 sunwukong kernel: [ 362.237101] wlan0: associate with XX:XX:XX:XX:XX (try 3/3)
Dec 20 23:37:09 sunwukong kernel: [ 362.341202] wlan0: association with XX:XX:XX:XX:XX timed out
Dec 20 23:37:09 sunwukong NetworkManager[832]: <info> (wlan0): supplicant interface state: associating -> disconnected
Dec 20 23:37:09 sunwukong wpa_supplicant[851]: wlan0: CTRL-EVENT-SCAN-STARTED
Dec 20 23:37:09 sunwukong NetworkManager[832]: <info> (wlan0): supplicant interface state: disconnected -> scanning
Dec 20 23:37:10 sunwukong wpa_supplicant[851]: wlan0: SME: Trying to authenticate with XX:XX:XX:XX:XX (SSID='MyNetwork' freq=2462 MHz)
Dec 20 23:37:10 sunwukong kernel: [ 363.300500] wlan0: authenticate with XX:XX:XX:XX:XX
Dec 20 23:37:10 sunwukong kernel: [ 363.303777] wlan0: send auth to XX:XX:XX:XX:XX (try 1/3)
Dec 20 23:37:10 sunwukong NetworkManager[832]: <info> (wlan0): supplicant interface state: scanning -> authenticating
Dec 20 23:37:10 sunwukong wpa_supplicant[851]: wlan0: Trying to associate with XX:XX:XX:XX:XX (SSID='MyNetwork' freq=2462 MHz)
Dec 20 23:37:10 sunwukong kernel: [ 363.306135] wlan0: authenticated
Dec 20 23:37:10 sunwukong kernel: [ 363.306387] iwlwifi 0000:04:00.0 wlan0: disabling HT as WMM/QoS is not supported by the AP
Dec 20 23:37:10 sunwukong kernel: [ 363.306394] iwlwifi 0000:04:00.0 wlan0: disabling VHT as WMM/QoS is not supported by the AP
Dec 20 23:37:10 sunwukong kernel: [ 363.309820] wlan0: associate with XX:XX:XX:XX:XX (try 1/3)
Dec 20 23:37:10 sunwukong NetworkManager[832]: <info> (wlan0): supplicant interface state: authenticating -> associating
Dec 20 23:37:10 sunwukong kernel: [ 363.413907] wlan0: associate with XX:XX:XX:XX:XX (try 2/3)
Dec 20 23:37:10 sunwukong kernel: [ 363.441652] wlan0: associate with XX:XX:XX:XX:XX (try 3/3)
Dec 20 23:37:10 sunwukong kernel: [ 363.553979] wlan0: association with XX:XX:XX:XX:XX timed out
Dec 20 23:37:10 sunwukong NetworkManager[832]: <info> (wlan0): supplicant interface state: associating -> disconnected
Dec 20 23:37:11 sunwukong wpa_supplicant[851]: wlan0: CTRL-EVENT-SCAN-STARTED
Dec 20 23:37:11 sunwukong NetworkManager[832]: <info> (wlan0): supplicant interface state: disconnected -> scanning
Dec 20 23:37:11 sunwukong wpa_supplicant[851]: wlan0: SME: Trying to authenticate with XX:XX:XX:XX:XX (SSID='MyNetwork' freq=2462 MHz)
Dec 20 23:37:11 sunwukong kernel: [ 365.016121] wlan0: authenticate with XX:XX:XX:XX:XX
Dec 20 23:37:11 sunwukong NetworkManager[832]: <info> (wlan0): supplicant interface state: scanning -> authenticating
Dec 20 23:37:11 sunwukong wpa_supplicant[851]: wlan0: Trying to associate with XX:XX:XX:XX:XX (SSID='MyNetwork' freq=2462 MHz)
Dec 20 23:37:11 sunwukong kernel: [ 365.019323] wlan0: send auth to XX:XX:XX:XX:XX (try 1/3)
Dec 20 23:37:11 sunwukong kernel: [ 365.021951] wlan0: authenticated
Dec 20 23:37:11 sunwukong kernel: [ 365.022200] iwlwifi 0000:04:00.0 wlan0: disabling HT as WMM/QoS is not supported by the AP
Dec 20 23:37:11 sunwukong kernel: [ 365.022209] iwlwifi 0000:04:00.0 wlan0: disabling VHT as WMM/QoS is not supported by the AP
Dec 20 23:37:11 sunwukong kernel: [ 365.022934] wlan0: associate with XX:XX:XX:XX:XX (try 1/3)
Dec 20 23:37:11 sunwukong NetworkManager[832]: <info> (wlan0): supplicant interface state: authenticating -> associating
Dec 20 23:37:11 sunwukong kernel: [ 365.127032] wlan0: associate with XX:XX:XX:XX:XX (try 2/3)
Dec 20 23:37:12 sunwukong kernel: [ 365.231099] wlan0: associate with XX:XX:XX:XX:XX (try 3/3)
Dec 20 23:37:12 sunwukong kernel: [ 365.335165] wlan0: association with XX:XX:XX:XX:XX timed out
Dec 20 23:37:12 sunwukong wpa_supplicant[851]: wlan0: CTRL-EVENT-SSID-TEMP-DISABLED id=0 ssid="MyNetwork" auth_failures=1 duration=10
Dec 20 23:37:12 sunwukong NetworkManager[832]: <info> (wlan0): supplicant interface state: associating -> disconnected
Dec 20 23:37:17 sunwukong wpa_supplicant[851]: wlan0: CTRL-EVENT-SCAN-STARTED
Dec 20 23:37:17 sunwukong NetworkManager[832]: <info> (wlan0): supplicant interface state: disconnected -> scanning
Dec 20 23:37:22 sunwukong wpa_supplicant[851]: wlan0: CTRL-EVENT-SCAN-STARTED
Dec 20 23:37:23 sunwukong wpa_supplicant[851]: wlan0: CTRL-EVENT-SSID-REENABLED id=0 ssid="MyNetwork"
Dec 20 23:37:23 sunwukong wpa_supplicant[851]: wlan0: SME: Trying to authenticate with XX:XX:XX:XX:XX (SSID='MyNetwork' freq=2462 MHz)
Dec 20 23:37:23 sunwukong kernel: [ 376.204910] wlan0: authenticate with XX:XX:XX:XX:XX
Dec 20 23:37:23 sunwukong NetworkManager[832]: <info> (wlan0): supplicant interface state: scanning -> authenticating
Dec 20 23:37:23 sunwukong kernel: [ 376.208187] wlan0: send auth to XX:XX:XX:XX:XX (try 1/3)
Dec 20 23:37:23 sunwukong wpa_supplicant[851]: wlan0: Trying to associate with XX:XX:XX:XX:XX (SSID='MyNetwork' freq=2462 MHz)
Dec 20 23:37:23 sunwukong kernel: [ 376.210772] wlan0: authenticated
Dec 20 23:37:23 sunwukong kernel: [ 376.211026] iwlwifi 0000:04:00.0 wlan0: disabling HT as WMM/QoS is not supported by the AP
Dec 20 23:37:23 sunwukong kernel: [ 376.211032] iwlwifi 0000:04:00.0 wlan0: disabling VHT as WMM/QoS is not supported by the AP
Dec 20 23:37:23 sunwukong kernel: [ 376.214269] wlan0: associate with XX:XX:XX:XX:XX (try 1/3)
Dec 20 23:37:23 sunwukong NetworkManager[832]: <info> (wlan0): supplicant interface state: authenticating -> associating
Dec 20 23:37:23 sunwukong kernel: [ 376.318367] wlan0: associate with XX:XX:XX:XX:XX (try 2/3)
Dec 20 23:37:23 sunwukong kernel: [ 376.422434] wlan0: associate with XX:XX:XX:XX:XX (try 3/3)
Dec 20 23:37:23 sunwukong kernel: [ 376.526499] wlan0: association with XX:XX:XX:XX:XX timed out
Dec 20 23:37:23 sunwukong wpa_supplicant[851]: wlan0: CTRL-EVENT-SSID-TEMP-DISABLED id=0 ssid="MyNetwork" auth_failures=2 duration=20
Dec 20 23:37:23 sunwukong NetworkManager[832]: <info> (wlan0): supplicant interface state: associating -> disconnected
Dec 20 23:37:33 sunwukong NetworkManager[832]: <warn> Activation (wlan0/wireless): association took too long.
Dec 20 23:37:33 sunwukong NetworkManager[832]: <info> (wlan0): device state change: config -> need-auth (reason 'none') [50 60 0]
Dec 20 23:37:33 sunwukong NetworkManager[832]: <warn> Activation (wlan0/wireless): asking for new secrets
Dec 20 23:37:33 sunwukong NetworkManager[832]: <info> (wlan0): supplicant interface state: disconnected -> inactive
Dec 20 23:37:33 sunwukong dbus[680]: [system] Activating service name='org.freedesktop.hostname1' (using servicehelper)
Dec 20 23:37:33 sunwukong dbus[680]: [system] Successfully activated service 'org.freedesktop.hostname1'
Dec 20 23:37:33 sunwukong kernel: [ 386.849446] systemd-hostnamed[2602]: Warning: nss-myhostname is not installed. Changing the local hostname might make it unresolveable. Please install nss-myhostname!
Dec 20 23:39:33 sunwukong NetworkManager[832]: <warn> No agents were available for this request.
Dec 20 23:39:33 sunwukong NetworkManager[832]: <info> (wlan0): device state change: need-auth -> failed (reason 'no-secrets') [60 120 7]
Dec 20 23:39:33 sunwukong NetworkManager[832]: <info> NetworkManager state is now DISCONNECTED
Dec 20 23:39:33 sunwukong NetworkManager[832]: <info> Marking connection 'MyNetwork' invalid.
Dec 20 23:39:33 sunwukong NetworkManager[832]: <warn> Activation (wlan0) failed for connection 'MyNetwork'
Dec 20 23:39:33 sunwukong NetworkManager[832]: <info> (wlan0): device state change: failed -> disconnected (reason 'none') [120 30 0]
Dec 20 23:39:33 sunwukong NetworkManager[832]: <info> (wlan0): deactivating device (reason 'none') [0]
Dec 20 23:39:33 sunwukong wpa_supplicant[851]: wlan0: CTRL-EVENT-SCAN-STARTED