6.8 KiB
https://github.com/morrownr/8812au-20210629 https://github.com/morrownr/8821au-20210708 https://github.com/morrownr/8821cu-20210118 https://github.com/morrownr/88x2bu-20210702 https://github.com/morrownr/8814au
Note: This document and the start-mon.sh script will work with
adapters that use in-kernel drivers but it is not necessary as the use
of any of the many guides that are available should work fine as the
in-kernel drivers work in the textbook, standards compliant manner.
Please submit corrections or additions via Issues.
Monitor mode, or RFMON (Radio Frequency MONitor) mode, allows a computer
with a wireless network interface controller (WNIC) to monitor all
traffic received on a wireless channel. Monitor mode allows packets to
be captured without having to associate with an access point or ad hoc
network first. Monitor mode only applies to wireless networks, while
promiscuous mode can be used on both wired and wireless networks.
Monitor mode is one of the eight modes that 802.11 wireless cards and
adapters can operate in: Master (acting as an access point), Managed
(client, also known as station), Ad hoc, Repeater, Mesh, Wi-Fi Direct,
TDLS and Monitor mode.
Note: This document and the start-mon.sh script have been tested on the
following:
Kali Linux Raspberry Pi OS Linux Mint Ubuntu
Steps to start/test monitor mode
Install USB WiFi adapter and driver per instructions.
Update system
sudo apt update
sudo apt full-upgrade
Ensure WiFi radio is not blocked
sudo rfkill unblock wlan
Install aircrack-ng (optional)
sudo apt install -y aircrack-ng
Check wifi interface information
iw dev
Information
The wifi interface name wlan0 is used in this document but you will
need to substitute the name of your wifi interface while using this
document.
Enter and check monitor mode
A script called start-mon.sh is available in the driver directory.
It will automate much of the following.
Usage:
sudo ./start-mon.sh [interface:wlan0]
Note: If you want to do things manually, continue below.
Disable interfering processes (see note about start-mon.sh below)
sudo airmon-ng check kill
Note: start-mon.sh is capable of disabling interfering processes. It
uses a different method than airmon-ng. Airmon-ng kills the processes
whereas start-mon.sh simply stops the processes and restarts them
when the script terminates. Stopping the processes seems to have some
advantages over killing them.
Advantage 1: When killing the very clever interfering processes, you may find that interfering processes are able to spawn new processes that will continue to interfer. Stopping the interfering processes does not seem to trigger the spawning of new processes.
Advantage 2: If you use more than one wifi adapter/card in the system, and if you need one of the adapter/cards to stay connected to the internet, killing the processes may cause your internet connection to drop. Stopping the processes does not cause your internet connection to drop.
Advantage 3: Stopping the processes allows the processes to be restarted.
The start-mon.sh script can put your interface in monitor mode,
properly configured, and then return your system, including stopped
processes and interface to original settings. This can reduce reboots
that sometimes might have been needed to reset things to normal operation.
Change to monitor mode
Option 1 (the airmon-ng way)
Note: This option may not work with some driver/adapter combinations
(I'm looking at you Realtek). If this option does not work, you can
use Option 2 or the start-mon.sh script that was previously mentioned.
sudo airmon-ng start <wlan0>
Option 2 (the manual way)
Check the wifi interface name and mode
iw dev
Take the interface down
sudo ip link set <wlan0> down
Set monitor mode
sudo iw <wlan0> set monitor control
Bring the interface up
sudo ip link set <wlan0> up
Verify the mode has changed
iw dev
Test injection
Option for 5 GHz and 2.4 GHz
sudo airodump-ng <wlan0> --band ag
Option for 5 GHz only
sudo airodump-ng <wlan0> --band a
Option for 2.4 GHz only
sudo airodump-ng <wlan0> --band g
Set the channel of your choice
sudo iw dev <wlan0> set channel <channel> [NOHT|HT20]
sudo aireplay-ng --test <wlan0>
Test deauth
Option for 5 GHz and 2.4 GHz
sudo airodump-ng <wlan0> --band ag
Option for 5 GHz only
sudo airodump-ng <wlan0> --band a
Option for 2.4 GHz only
sudo airodump-ng <wlan0> --band g
sudo airodump-ng <wlan0> --bssid <routerMAC> --channel <channel of router>
Option for 5 GHz:
sudo aireplay-ng --deauth 0 -c <deviceMAC> -a <routerMAC> <wlan0> -D
Option for 2.4 GHz:
sudo aireplay-ng --deauth 0 -c <deviceMAC> -a <routerMAC> <wlan0>
Revert to Managed Mode
Check the wifi interface name and mode
iw dev
Take the wifi interface down
sudo ip link set <wlan0> down
Set managed mode
sudo iw <wlan0> set type managed
Bring the wifi interface up
sudo ip link set <wlan0> up
Verify the wifi interface name and mode has changed
iw dev
Change the MAC Address before entering Monitor Mode
Check the wifi interface name, MAC address and mode
iw dev
Take the wifi interface down
sudo ip link set dev <wlan0> down
Change the MAC address
sudo ip link set dev <wlan0> address <new mac address>
Set monitor mode
sudo iw <wlan0> set monitor control
Bring the wifi interface up
sudo ip link set dev <wlan0> up
Verify the wifi interface name, MAC address and mode has changed
iw dev
Change txpower
sudo iw dev <wlan0> set txpower fixed 1600
Note: 1600 = 16 dBm
Information
airodump-ng can receive and interpret key strokes while running.
The following list describes the currently assigned keys and supported
actions:
a
Select active areas by cycling through these display options:
AP+STA; AP+STA+ACK; AP only; STA only
d
Reset sorting to defaults (Power)
i
Invert sorting algorithm
m
Mark the selected AP or cycle through different colors if the selected AP is
already marked
o
Enable colored display of APs and their stations.
p
Disable colored display.
q
Quit program.
r
(De-)Activate realtime sorting -
applies sorting algorithm every time the display will be redrawn
s
Change column to sort by, which currently includes:
BSSID;
PWR level;
Beacons;
Data packets;
Packet rate;
Channel;
Max. data rate;
Encryption;
Strongest Ciphersuite;
Strongest Authentication;
ESSID