By default, your wireless interfaces are set to "Managed" mode. A wireless interface set to "Managed" mode can only capture packets with a "Destination MAC" set to its own MAC address.
If you want to be able to capture all packets within the range of your wireless device, you need to set the mode of your wireless interface to "Monitor".
However, not all wireless devices support monitor mode, so you will need to check that your device is compatible.
If you have Aircrack-ng installed, you can run the following commands in your terminal:
airmon-ngto list all your network interfaces.
arimon-ng check killto stop interfering network processes.
airmon-ng start wlan0to start your network interface in monitor mode, in this case we are using
If you are not using Aircrack-ng, you can run the following commands in your terminal:
iwconfigto view your wireless interfaces and check their current mode.
ifconfig wlan0 downto disable the network interface you wish to change, in this case it is
iwconfig wlan0 mode monitorto change the mode of
ifconfig wlan0 upto re-enable your network interface.
You may need to run these commands as
root or a user with privileges.
Once you have re-enabled your network interface, you can run
iwconfig to confirm your wireless interface is running with "Monitor" mode:
wlan0 IEEE 802.11b ESSID:"" Nickname:"<WIFI@REALTEK>" Mode:Monitor Frequency:2.412 GHz Access Point: Not-Associated