I have a Raspberry Pi 2 running Jessie.

root@raspberrypi:/etc# cat os-release
PRETTY_NAME="Raspbian GNU/Linux 8 (jessie)"
NAME="Raspbian GNU/Linux"
VERSION="8 (jessie)"

The 'Edimax EW-7811Un 802.11n Wireless Adapter [Realtek RTL8188CUS]' arrive today I ordered from Amazon.com:

I was expecting this to work out of the box, but I'm getting an error message and not sure what the fix is for it. I have been able to ssh into the Raspberry Pi 2, but the connection gets dropped. And it doesn't get activated again until I re-connect the ethernet cable, and then the Wifi IP address starts to work.

This is the error message from ifup wlan0:

root@raspberrypi:/etc/network# ifup wlan0
ioctl[SIOCSIWAP]: Operation not permitted
ioctl[SIOCSIWENCODEEXT]: Invalid argument
ioctl[SIOCSIWENCODEEXT]: Invalid argument


root@raspberrypi:/etc/network# lsusb | grep Edimax
Bus 001 Device 007: ID 7392:7811 Edimax Technology Co., Ltd EW-7811Un 802.11n Wireless Adapter [Realtek RTL8188CUS]


root@raspberrypi:/etc/wpa_supplicant# cat wpa_supplicant.conf
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev


root@raspberrypi:/etc/network# cat interfaces
# interfaces(5) file used by ifup(8) and ifdown(8)

# Please note that this file is written to be used with dhcpcd
# For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf'

# Include files from /etc/network/interfaces.d:
source-directory /etc/network/interfaces.d

auto lo
iface lo inet loopback

iface eth0 inet manual

allow-hotplug wlan0
iface wlan0 inet manual
    wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

allow-hotplug wlan1
iface wlan1 inet manual
    wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
  • "I'm getting an error message" don't keep it secret!
    – Milliways
    Apr 11, 2016 at 23:01
  • The error message is above: ioctl[SIOCSIWAP]: Operation not permitted ioctl[SIOCSIWENCODEEXT]: Invalid argument ioctl[SIOCSIWENCODEEXT]: Invalid argument Apr 12, 2016 at 2:46
  • That is only an error for the ifup command - which you don't need and AFAIK doesn't work on dhcpcd
    – Milliways
    Apr 12, 2016 at 2:56
  • @Milliways OK, thanks for clearing that up. I thought it might be a symptom of the problem. The main problem is, after two minutes through ssh without any activity it drops the connection. If I remove the WiFi doggle and put it back in, or the ethernet cable, the WiFi connection because active again. I did see a web page where someone's work around was to run a CRON job to do a ping to the router every minute or so, but that's seems like a strange thing to have to do. I've never had to do that with WiFi on any other system. Apr 12, 2016 at 11:37


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