increase Wifi power (TX Power) Kali Linux
Different countries have different laws and technical regulations, including on Wi-Fi. In some countries, it is not allowed to use the frequencies of some Wi-Fi channels (for example, in the USA, channels 12, 13 and 14 cannot be used). In most countries, the limit on the power of WiFi signal is 20.0 dBm. But there are countries in which there is a limit of 30.0 dBm. You can use this loophole (make WiFi card think that it is in a country where 30.0 dBm is allowed) and increase its power (TX Power) to 30.0dBm.
For WiFi devices, there is such a thing as a controlling domain (regulatory domain or “regdomain”) – it is in this parameter that the country in which this device is supposed to work is indicated. There is also a companion database in which the permitted frequencies and the power allowed for them are recorded for each country.
The algorithm is as follows:
- we set the system-wide setting of the control domain to the value of the country where the power is allowed at 30.0dBm;
- We set the increased power for the wireless adapter.
In theory, the described method should work for many wireless cards, but in practice there are the following limitations:
- physical inability of the cards to operate at capacities of more than 20.0 dBm (for example, the wireless interface initially shows 15.0 dBm power with 20.0 dBm enabled – in this case it will not be possible to increase the power above 15.0 dBm in any way)
- driver features, for example, some drivers ignore system settings. This is not an intractable problem – but each model needs its own approach (usually a small patch for the driver is required) or (which is much simpler), a patch of the control domain database.
See what you are allowed right now and what your wireless adapter is capable of using the command:
sudo iw list
The countries in which channels 1 to 13 are allowed at a power of 30.0 dBm are (for example):
- Bz
- Gy
- Nz
- VE
Please note that for 5GHz channels they have different values (different list of allowed frequencies and powers).
So lets start >
first We stop the services that maybe using the wifi adapter (this is optional, should work with them):
sudo systemctl stop NetworkManager
sudo airmon-ng check kill
To find out which region settings are currently in effect, run the command:
sudo iw reg get
The string country 00 says that I have not set any value and apply the default settings.
Now set the control domain to the value of BZ:
sudo iw reg set BZ
You can immediately check whether the settings were taken:
sudo iw reg get
At the same time you can see the new features with the command:
sudo iw list
If, at this stage, the settings of the replacement manager were not applied (not established) at the system level, then it will not be possible to increase the power of the WiFi adapter until you understand the reason for this.
You can view the name of the wireless interface and its current status with the command:
sudo iw dev
Next, increase the power (replace wlan0 with the name of your wireless interface):
sudo ip link set wlan0mon down
sudo iw dev wlan0mon set txpower fixed 30mBm
sudo ip link set wlan0mon up
Checking:
sudo iw dev
The txpower has been increase to 30.00 dBm .
Conclusion
Increasing the power of a Wi-Fi adapter is undoubtedly useful only when jamming Wi-Fi, as well as in deauthentication attacks. In all other attacks, the increase in power does not necessarily change anything, because power affects how your Wi-Fi adapter “shouts” loudly, but does not increase its sensitivity (how well it “hears” others).
Also, be aware of the possibility of unlocking some channels that may not be available in your country.
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