Wireless Network Adapter monitor mode
Image by Kevin Phillips from Pixabay

Wireless Network Adapter monitor mode

Just a thought, but there is a capitalization error. It should be:

sudo iwconfig wlan1 mode Monitor

not:

sudo iwconfig wlan1 mode monitor

add non-free firmware to repository list ( /etc/apt/sources.list ) Replacing squeeze with whichever version you are using (wheezy, jessy, sid…):

echo “deb squeeze main non-free” > /etc/apt/sources.list echo “deb squeeze/updates main non-free” > /etc/apt/sources.list echo “deb squeeze-updates main non-free” > /etc/apt/sources.list echo “deb squeeze-backports main non-free” > /etc/apt/sources.list

update and install and reboot (make sure dongle is plugged in):

sudo apt-get update sudo apt-get update && sudo apt-get install firmware-realtek sudo reboot

Then:

sudo ifconfig wlan1 down sudo iwconfig wlan1 mode Monitor sudo ifconfig wlan1 up

Output:

jmunsch@NE-522:~$ sudo ifconfig wlan1 up && dmesg | tail -n 4 [891] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cufw.bin [884] rtl8192cu: MAC auto ON okay! [850] rtl8192cu: Tx queue select: 0x05 [867] rtl8192c_common: Loading firmware file rtlwifi/rtl8192cufw.bin jmunsch@NE-522:~$ lsusb | tail -n 1 && iwconfig wlan1 Bus 002 Device 010: ID 7392:7811 Edimax Technology Co., Ltd EW-7811Un 802.11n Wireless Adapter [Realtek RTL8188CUS] wlan1 IEEE 802.11bgn Mode:Monitor Tx-Power=20 dBm Retry long limit:7 RTS thr=2347 B Fragment thr:off Power Management:off

Source: raspberrypi.stackexchange.com