At the time of the first wired LANs, it was difficult for an intruder to interfere with other machines, since it was necessary to physically access a network outlet.
Since Wi-Fi has become the norm in many homes, it is essential to protect access with a password (WPA2 key in general) so that no one can access your data or enjoy your Internet connection.
But there is always a risk that a user can hack the Wi-Fi password. Netcut allows you to check which devices are connected to your network, and control access to the Internet.
Netcut is a free utility for analyzing and controlling devices on the local network, available for Windows and Android. As part of this tutorial, we present the PC version, but the features are similar in the download version on the Google Play Store.
Analyze and Control Wi-Fi Network
The Netcut installation is fully automated. A window will only open asking you to agree to install WinPcap if it is not already installed on your computer. This component allows Netcut to perform the capture and transmission of network packets, it is necessary for the operation of this software.
You do not have to restart the computer at the end of the installation to take advantage of Netcut features. This utility immediately opens a tab in your default browser and scans your local network. The connected devices are displayed, you can identify them by the IP address, the MAC address, and their mark.
Netcut detects all machines that connect to the network: computers, tablets, smartphones, consoles, televisions, multimedia boxes, and home automation or security accessories.
By default, unknown devices are displayed in the center column. You can drag them using the mouse in the right column to indicate that they are trusted or in the left column to add them to the list of devices to block.
In our case, we observe that by default, Netcut has placed the computer running this software in the list of secure devices, just like the Wi-Fi router that acts as a network gateway, identified by the local IP address 192.168.1.254.
The first thing to do to ensure that no stranger is connected to the local network is to check the devices displayed in the center column. In our case, we see a “Google” brand accessory. This is a Chromecast, so we move it to the right column to confirm that it is a trusted customer.
This is just one way to better organize Netcut, because access to the network and the Internet is fully allowed for all devices displayed in the center and right columns. The advantage is that during the next run of the software, only new unknown clients will be displayed in the central column.
To quickly recognize each of the clients connected to the LAN from Netcut, you can customize the device names. Just enter your description in the “name” field to explicitly rename connected devices.
In the “Records” page of the application, Netcut displays events related to connecting or disconnecting clients on your local network. This provides a history of device access to the network, to precisely check when a device has connected.
Functionality control buttons
In the horizontal bar at the top of the “Users” page (the one that appears by default), there is a cursor and four buttons corresponding to actions.
- The cursor manages the activation of Netcut Defender, a tool to guard against other devices that would also run this application on the same network. Be sure to keep the Netcut Defender cursor on “On” to avoid being vulnerable to attack by other users.
- The padlock button is used to block access to your Wi-Fi network by new users. This feature can only be used in the paid version of Netcut.
- The following symbol is an option to disconnect Internet access for all devices connected to the network at the same time and in one click. This feature can only be used in the paid version of Netcut.
- A refresh icon is used to launch a new scan of the network, the software then displays in seconds if new devices have connected or disconnected.
- The last feature is to search for a device by name, IP address, MAC address, or brand. It is especially useful in the case of a network where a large number of devices is present simultaneously.
Blocking a user’s Internet access
One of the main features of Netcut is that you can completely block access to the Internet from a machine connected to your local network. The software can also prevent an intruder from enjoying your connection for free, blocking Internet access on your child’s phone or tablet when they have reached their daily quota, or limiting the bandwidth allowed for a particular device.
There are several ways to cut access to the Internet connection for a LAN device through Netcut:
- The simplest way is to drag the target device in the left-hand column with the mouse, which immediately removes the connection from the Internet, although it remains connected to the Wi-Fi network. The same result can be obtained by clicking on the blue Wi-Fi icon in the box indicating the device;
- In order not to remove all the Internet access to the machine, but to regulate the bandwidth, it is necessary to manage the position of the cursor present in the box representing the device. The further it is to the left, the lower the bandwidth. In our tests, the bandwidth was already very low with the cursor positioned at half;
- The software also allows you to define a blocking time slot, by selecting the button in the form of alarm clock. You will then need to fill in one hour of start and end of daily blocking. In the same window, it is possible to set a disconnection countdown: the connection of the device to the Internet will be blocked for the specified duration. To cancel the time zone or the countdown, simply open this window again with the alarm button and select the “Reset” button.