Monitor mode is a feature in Linux that allows the computer’s wireless network interface card (NIC) to capture and monitor all network traffic on a specific channel. This can be a useful tool for analyzing network traffic, detecting network intrusions, and troubleshooting network connectivity issues. In this article, we will discuss how to start and stop monitor mode in Linux.

Starting Monitor Mode

To start monitor mode in Linux, you will need to have a wireless NIC that supports monitor mode. Most modern wireless NICs have this capability, but it is always a good idea to check the specifications of your wireless card to ensure that it supports monitor mode.

Once you have confirmed that your wireless card supports monitor mode, you can start monitor mode by using the following commands in the terminal:

1. Open a terminal window by pressing Ctrl+Alt+T.
2. Type the following command to list the available wireless interfaces on your system:

iw dev

1. Identify the wireless interface that you want to put into monitor mode. It will be listed as phy0, wlan0, wlp2s0, or something similar.
2. Put the wireless interface into monitor mode by using the following command, replacing wlan0 with the name of your wireless interface:

sudo iw dev wlan0 set monitor control

1. You can verify that the wireless interface is now in monitor mode by using the following command:

iw wlan0 interface dump | grep type

If the output shows type monitor, then your wireless interface is in monitor mode and is ready to capture network traffic.

Stopping Monitor Mode

To stop monitor mode in Linux, you can use the following commands in the terminal:

1. Open a terminal window by pressing Ctrl+Alt+T.
2. Type the following command to list the available wireless interfaces on your system:

iw dev

1. Identify the wireless interface that is currently in monitor mode.
2. Put the wireless interface back into managed mode by using the following command, replacing wlan0 with the name of your wireless interface:

sudo iw dev wlan0 set type managed

1. You can verify that the wireless interface is now in managed mode by using the following command:

iw wlan0 interface dump | grep type

If the output shows type managed, then your wireless interface is no longer in monitor mode.

In conclusion, monitor mode can be a powerful tool for network analysis and troubleshooting in Linux. By following the steps outlined in this article, you can easily start and stop monitor mode on your wireless interface. Just remember to use this feature responsibly and in accordance with your local laws and regulations.