Introduction
This tutorial will take you through some simple steps to increase the transmission power (txpower) of a wireless card.
This is not necessary for hacking wifi, but will usually increase your success rate, especially for targets that are far from you.
802.11 transmission powers are regulated in almost all countries. Following this tutorial may cause you to go over these regulations.
Requirements
- Linux
- A compatible wireless card with compatible drivers. Not all cards allow for higher transmission power.
- Basic command-line knowledge.
- Tools (installed by default on kali and many distros)
- iw
- iwconfig
- ifconfig
Steps
1. Make sure you card is plugged in and working. You may run the following in a terminal to check:
iwconfig
You should see something like this:
My interface happens to be wlan1. Yours could be wlan0 or something else.
Look at the third line, Tx-Power=18 dBm, this is what we want to increase.
2. Next, we need to set the regulatory domain to one that allows higher transmission powers. On my system, ‘US‘ allows me to go up to 30 dBm. If it doesn’t work for you, try ‘BO‘ instead:
iw reg set US
or
iw reg set BO
3. Now run: iw reg get
(2402 - 2472 @ 40), (N/A, 30), (N/A) This line indicates that we can now go up to 30 dBm on 2.4Ghz channels.
4. Now take the interface down with ifconfig:
ifconfig wlan1 down
You should get no output, unless errors occured.
5. Set the txpower:
iwconfig wlan1 txpower 30
You should get no output.
6. Bring the interface up:
ifconfig wlan1 up
Again, no output.
7. Run iwconfig again to make sure everything worked:
As you can see, Tx-Power=30 dBm