There are couple of things that we should consider in choosing an usb network card to partner with BackTrack. Aside for wifi injection capability, it is always good to have the one with higher power as legally ( and budget-wise) as possible.
This is the reason why we are using AWUS036NEH. Aside for the removable (which means upgradable) rp-sma antenna, this beast can have a transmit power up to 1000mW (30dBm). Unfortunately default installation shows 100mW!!
1. Boot your Kali.
2. Ensure that the usb network adapter is detected under your Kali installation.
The above example is running via VMWARE and I intentionally removed any other network card so that only network adapter I should see would be my alfa card (awus036neh) . In any case, you should probably see another card named eth0, or if you booted using a live cd (or usb), you might also see other wireless adapter being detected (ie. wlan1 or wlan0). In anyway, ensure that you are looking and configuring the correct adapter. The best bet is to compare the mac address (ie. HWaddr information) of the adapter you are configuring and the mac address on the sticker printer at the bottom of your alfa card.
As mentioned, only about 100mW of power is used unless you explicitly set it to max. The picture below shows the transmit power on a default install.
You can run airmon-ng to see wireless adapters detected on your Kali.
If you executed the airmon-ng, ensure to disable monitor mode for your alfa card.
Now let’s get started, first bring the interface down. Then execute the “iw reg set BO”. Then followed by starting airmon-ng. See the commands on the picture below:
You can run “iwconfig [interface]” again to see that the transmit power is now set to 30dBm (1000mW).
Since we have set the alfa card to monitor mode, just simply run “airmon-ng stop [interface]” to disable monitor mode.
You can run “iwconfig” if you still want to see the current tx power if the card.