The shield in the main window is an button for starting/stopping of protection. Also it is indicator activity of service in real time.

After changing any options in the settings, you need to restart the protection service, for changes to take effect.

For correctly work of modes invulnerability and recovery, you need to have the root and busybox, which must contain the arp utility. The default mode (arp check) does not require the root or busybox.

If you are using a mode that requires root access, it is recommended to configure root manager so that the permissions is granted automatically, for guarantee correct work if protection service will be restarted (eg, system will relaunch it or when updating the app).

For the test you need to have any program, which contains arp spoofer. Wifikill or interceptor traffic, it does not matter, because they all work on the same principle.

Check of ARP spoofer: Before moving on to the ARP Guard testing, it is recommended to check the work of the arp spoofer to make sure that everything is configured correctly. In this test is not necessary to include the protection, needs only to open the ARP Guard main window. Under the start button displays the current MAC address of the gateway and BSSID. What is needed:
1) Look at the MAC address of the gateway before the ARP Spoofing launch.
2) Run the arp spoofing. MAC address of the gateway will immediately change. If it does not, then something is wrong, check the settings in the arp spoofer.
Thus, MAC address of the gateway has changed, the attack was successful. Now you need to turn off the ARP Spoofer, disconnect the device (on which installed the ARP Guard) of a WiFi network and connect again, for clearing arp table.

Things to remember when testing the program in any mode: before moving on to testing, make sure the arp spoofer is not active, and the mac address of the gateway is correctly. If you have already passed arp spoofing, please disable arp spoofer and reconnect the device to the network again. If you want the application to respond to the attack, which began before to the activation of protection, you need to use 'bssid analysis' function, however, you first need to familiarize with possible problems when using this function.

Testing in the standard mode: Start the protection. After this you may run arp spoofer. The application will react to the attack, showing a notification. Wi-fi will turn off automatically if this feature is enabled in the settings.

Testing in the invulnerability mode: Start the protection. After this you may run arp spoofer. In the main window you can see that the MAC address of the gateway has not changed during the attack, the attack has failed.

Testing in the recovery mode: Start the protection. After this you may run arp spoofer. The application will react to the attack, showing a notification. Also in the program's main window can be seen as the MAC address of the gateway has been restored to the original. Program registers gateway address as permanent, so further attacks will be impossible. That is why, up to reconnect to the network, the program will not show warnings notifications in case of further attacks.

App shows warning with gateway as attacker: likely the 'BSSID analysis' function is active. In this case, you must go to settings, turn off this function and restart protection. Keep in mind that if you use the invulnerability mode, the Internet will not be available until the reconnection to the network. That is why the use of 'BSSID analysis' requires caution and understanding.

Nothing happens when testing of program:
1) Check, what mode the ARP Guard works. The warning will not be issued in the case of invulnerability mode. When using recovery mode, a warning will be shown only once, up to reconnect to the network.
2) ARP spoofer must not work before protection will launch. Also check the mac address of gateway at the moment of test. If you do not use bssid analysis, the attack must begin after the activation of the protection (or connection of device to network).
3) Read carefully the section "Method of testing", to make sure that everything is done correctly.

If you can not solve your problem, or you have any questions about this app, you may contact to my email