Raspberry Pi 无法连接到隐藏的 SSID WIFI

Question

我的 Raspberry Pi 上的 edimax ew-7811un 有问题。我尝试连接到一个隐藏的 SSID，我们将其称为“hiddenssid”，并使用 WPA2 个人密码“hiddenpassword”。我可以在 iwconfig 中看到 wifi 加密狗。我创建了一个 PSK 版本的密码：

$ wpa_passphrase "<Your Wifi SSID>" "<Your Wifi PASSWORD>"

这是我的/etc/network/interfaces：

auto lo

iface lo inet loopback
iface eth0 inet dhcp

auto wlan0
allow-hotplug wlan0
iface wlan0 inet dhcp
   wpa-scan-ssid 1
   wpa-ap-scan 1
   wpa-key-mgmt WPA-PSK
   wpa-proto RSN WPA
   wpa-pairwise CCMP TKIP
   wpa-group CCMP TKIP
   wpa-ssid "hiddenssid"
   wpa-psk pskpassword

iface default inet dhcp

这是我输入时得到的结果sudo ifup --force wlan0：

ioctl[SIOCSIWAP]: Operation not permitted
ioctl[SIOCSIWENCODEEXT]: Invalid argument
ioctl[SIOCSIWENCODEEXT]: Invalid argument
Internet Systems Consortium DHCP Client 4.2.2
Copyright 2004-2011 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/

Listening on LPF/wlan0/74:da:somethingsomething
Sending on   LPF/wlan0/74:da:somethingsomething
Sending on   Socket/fallback
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 3
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 7
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 12
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 21
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 18
No DHCPOFFERS received.
No working leases in persistent database - sleeping.

这是iwconfig：

wlan0     unassociated  Nickname:"<WIFI@REALTEK>"
          Mode:Managed  Frequency=2.437 GHz  Access Point: Not-Associated
          Sensitivity:0/0
          Retry:off   RTS thr:off   Fragment thr:off
          Power Management:off
          Link Quality:0  Signal level:0  Noise level:0
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

lo        no wireless extensions.

eth0      no wireless extensions.

你能帮我么？