我有一台运行 Ubuntu 12.04.1 LTS 的 Beaglebone，带有 Realtek Wifi USB 加密狗：
ubuntu@arm:~$ lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 002: ID 0bda:8176 Realtek Semiconductor Corp. RTL8188CUS 802.11n WLAN
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
我可以使用以下 /etc/network/interfaces 文件成功连接到我的 Netgear R6300：
auto lo
iface lo inet loopback
# WiFi Example
auto wlan1
iface wlan1 inet dhcp
wpa-ssid "FalkorSystems"
wpa-psk "<omitted>"
但是我尝试连接到我的 Verizon MiFi 设备“Jetpack 4260L”，但没有任何成功。我可以从我的 Mac 顺利连接到 MiFi。MiFi 设置了 WPA2，就像 Netgear R6300 一样
auto lo
iface lo inet loopback
# WiFi Example
auto wlan1
iface wlan1 inet dhcp
wpa-ssid "FalkorMifi"
wpa-psk "<omitted>"
我也尝试过使用开放网络配置 MiFi，并且使用了：
auto lo
iface lo inet loopback
# WiFi Example
auto wlan1
iface wlan1 inet dhcp
wireless-ssid "FalkorMifi"
我还按照此处的说明在 Mac 上创建了一个接入点：
http://www.dummies.com/how-to/content/how-to-make-your-mac-a-wifi-access-point.html
而且我创建它时没有使用任何加密，所以我无法连接。
我会做：
> ifdown wlan1
> ifup wlan1
并且 ifup 命令将会挂起。
我也尝试过重新启动而不是执行 ifdown/ifup。
当它成功连接到我的 Netgear 时，dmesg 会告诉我：
[ 22.805207] cfg80211: Calling CRDA to update world regulatory domain
[ 25.983702] rtl8192cu: MAC address: 00:e0:4c:09:25:15
[ 25.983752] rtl8192cu: Board Type 0
[ 26.241514] rtlwifi: rx_max_size 15360, rx_urb_num 8, in_ep 1
[ 26.241561] cfg80211: Updating information on frequency 2412 MHz for a 20 MHz width channel with regulatory rule:
[ 26.241589] cfg80211: 2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A mBi, 2000 mBm)
[ 26.241608] cfg80211: Updating information on frequency 2417 MHz for a 20 MHz width channel with regulatory rule:
[ 26.241630] cfg80211: 2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A mBi, 2000 mBm)
[ 26.241647] cfg80211: Updating information on frequency 2422 MHz for a 20 MHz width channel with regulatory rule:
[ 26.241669] cfg80211: 2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A mBi, 2000 mBm)
[ 26.241686] cfg80211: Updating information on frequency 2427 MHz for a 20 MHz width channel with regulatory rule:
[ 26.241707] cfg80211: 2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A mBi, 2000 mBm)
[ 26.241725] cfg80211: Updating information on frequency 2432 MHz for a 20 MHz width channel with regulatory rule:
[ 26.241746] cfg80211: 2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A mBi, 2000 mBm)
[ 26.241764] cfg80211: Updating information on frequency 2437 MHz for a 20 MHz width channel with regulatory rule:
[ 26.241785] cfg80211: 2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A mBi, 2000 mBm)
[ 26.241802] cfg80211: Updating information on frequency 2442 MHz for a 20 MHz width channel with regulatory rule:
[ 26.241824] cfg80211: 2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A mBi, 2000 mBm)
[ 26.241841] cfg80211: Updating information on frequency 2447 MHz for a 20 MHz width channel with regulatory rule:
[ 26.241863] cfg80211: 2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A mBi, 2000 mBm)
[ 26.241880] cfg80211: Updating information on frequency 2452 MHz for a 20 MHz width channel with regulatory rule:
[ 26.241901] cfg80211: 2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A mBi, 2000 mBm)
[ 26.241919] cfg80211: Updating information on frequency 2457 MHz for a 20 MHz width channel with regulatory rule:
[ 26.241940] cfg80211: 2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A mBi, 2000 mBm)
[ 26.241957] cfg80211: Updating information on frequency 2462 MHz for a 20 MHz width channel with regulatory rule:
[ 26.241979] cfg80211: 2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A mBi, 2000 mBm)
[ 26.241996] cfg80211: Disabling freq 2467 MHz as custom regd has no rule that fits a 20 MHz wide channel
[ 26.242015] cfg80211: Disabling freq 2472 MHz as custom regd has no rule that fits a 20 MHz wide channel
[ 26.242034] cfg80211: Disabling freq 2484 MHz as custom regd has no rule that fits a 20 MHz wide channel
[ 26.242365] cfg80211: Ignoring regulatory request Set by core since the driver uses its own custom regulatory domain
[ 26.242916] cfg80211: Pending regulatory request, waiting for it to be processed...
[ 26.351209] ieee80211 phy0: Selected rate control algorithm 'rtl_rc'
[ 26.354357] usbcore: registered new interface driver rtl8192cu
[ 26.890970] udevd[271]: renamed network interface wlan0 to wlan1
[ 27.428810] init: udev-fallback-graphics main process (499) terminated with status 1
[ 27.502462] rtl8192cu: MAC auto ON okay!
[ 27.557706] rtl8192cu: Tx queue select: 0x05
[ 27.560618] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cufw.bin
[ 28.301232] ADDRCONF(NETDEV_UP): wlan1: link is not ready
[ 28.739235] init: isc-dhcp-server pre-start process (536) terminated with status 127
[ 43.829532] wlan1: authenticate with 84:1b:5e:ee:cd:8c (try 1)
[ 43.832231] wlan1: authenticated
[ 43.834082] wlan1: associate with 84:1b:5e:ee:cd:8c (try 1)
[ 43.839932] wlan1: RX AssocResp from 84:1b:5e:ee:cd:8c (capab=0x411 status=0 aid=3)
[ 43.839980] wlan1: associated
[ 43.858354] ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready
[ 54.338125] wlan1: no IPv6 routers present
当它无法连接到我的MiFi（配置为开放网络）时：
[ 20.060175] cfg80211: Calling CRDA to update world regulatory domain
[ 20.905690] rtl8192cu: MAC address: 00:e0:4c:09:25:15
[ 20.905740] rtl8192cu: Board Type 0
[ 21.561046] rtlwifi: rx_max_size 15360, rx_urb_num 8, in_ep 1
[ 21.561093] cfg80211: Updating information on frequency 2412 MHz for a 20 MHz width channel with regulatory rule:
[ 21.561119] cfg80211: 2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A mBi, 2000 mBm)
[ 21.561137] cfg80211: Updating information on frequency 2417 MHz for a 20 MHz width channel with regulatory rule:
[ 21.561159] cfg80211: 2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A mBi, 2000 mBm)
[ 21.561176] cfg80211: Updating information on frequency 2422 MHz for a 20 MHz width channel with regulatory rule:
[ 21.561198] cfg80211: 2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A mBi, 2000 mBm)
[ 21.561215] cfg80211: Updating information on frequency 2427 MHz for a 20 MHz width channel with regulatory rule:
[ 21.561237] cfg80211: 2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A mBi, 2000 mBm)
[ 21.561254] cfg80211: Updating information on frequency 2432 MHz for a 20 MHz width channel with regulatory rule:
[ 21.561276] cfg80211: 2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A mBi, 2000 mBm)
[ 21.561293] cfg80211: Updating information on frequency 2437 MHz for a 20 MHz width channel with regulatory rule:
[ 21.561314] cfg80211: 2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A mBi, 2000 mBm)
[ 21.561331] cfg80211: Updating information on frequency 2442 MHz for a 20 MHz width channel with regulatory rule:
[ 21.561352] cfg80211: 2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A mBi, 2000 mBm)
[ 21.561370] cfg80211: Updating information on frequency 2447 MHz for a 20 MHz width channel with regulatory rule:
[ 21.561391] cfg80211: 2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A mBi, 2000 mBm)
[ 21.561408] cfg80211: Updating information on frequency 2452 MHz for a 20 MHz width channel with regulatory rule:
[ 21.561430] cfg80211: 2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A mBi, 2000 mBm)
[ 21.561447] cfg80211: Updating information on frequency 2457 MHz for a 20 MHz width channel with regulatory rule:
[ 21.561469] cfg80211: 2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A mBi, 2000 mBm)
[ 21.561485] cfg80211: Updating information on frequency 2462 MHz for a 20 MHz width channel with regulatory rule:
[ 21.561507] cfg80211: 2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A mBi, 2000 mBm)
[ 21.561525] cfg80211: Disabling freq 2467 MHz as custom regd has no rule that fits a 20 MHz wide channel
[ 21.561544] cfg80211: Disabling freq 2472 MHz as custom regd has no rule that fits a 20 MHz wide channel
[ 21.561563] cfg80211: Disabling freq 2484 MHz as custom regd has no rule that fits a 20 MHz wide channel
[ 21.561894] cfg80211: Ignoring regulatory request Set by core since the driver uses its own custom regulatory domain
[ 21.562460] cfg80211: Pending regulatory request, waiting for it to be processed...
[ 22.324375] ieee80211 phy0: Selected rate control algorithm 'rtl_rc'
[ 22.327427] usbcore: registered new interface driver rtl8192cu
[ 22.782272] udevd[264]: renamed network interface wlan0 to wlan1
[ 23.326273] init: udev-fallback-graphics main process (497) terminated with status 1
[ 34.190986] rtl8192cu: MAC auto ON okay!
[ 34.224398] rtl8192cu: Tx queue select: 0x05
[ 34.225925] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cufw.bin
[ 34.741921] ADDRCONF(NETDEV_UP): wlan1: link is not ready
这里有人有什么想法吗？
谢谢！