How to detect Wi-Fi intruders, block them and secure your home network

If Wi-Fi slows down for no apparent reason or unknown devices appear while sharing content, for example on Smart TV, there may be an intruder connected to our Wi-Fi network without authorization. Understanding this is important not only to prevent some neighbor from “stealing” our Internet connection by increasing the bandwidth – i.e. the maximum amount of data that can be transferred through a connection in a given period of time – but it can also affect our IT security. Unauthorized access to our home network could expose files, credentials, etc., to potential risks. In this in-depth analysis we will see how to identify possible Wi-Fi intruders using both empirical and slightly more technical methods, and above all how to reduce the probability of this happening.

How to understand if there are intruders on your Wi-Fi and block them

A first check, within everyone’s reach, to understand if there are intruders on our Wi-Fi is to observe the router’s LEDs. These lights reflect network activity on your device: a rapid, continuous flash suggests that data traffic is currently occurring. If we temporarily disconnected all the devices in the house and the router continued to show activity, we could assume the presence of external access. It must be said that this is a simple method to implement but it is far from “scientific”, given that many devices can generate traffic in the background without us realizing it.

For a more reliable check it is necessary to access the router’s administration panel, i.e. the interface that allows you to manage the settings of your network. This step requires knowing the IP address of the router, which represents the access point to its configuration. The most common addresses are 192.168.0.1, 192.168.1.1 or 192.168.1.254. Try entering these “codes” one at a time into your browser’s address bar and press Enter on your keyboard. If one of these works, you should be able to see a screen asking you to log in to the router panel by entering your username and password. Once upon a time many manufacturers used the pair admin and admin or admin and password, but since more and more providers use personalized usernames and passwords, we suggest you check the label on the back of your router to find out which data to enter in the fields in question. Clearly, if you have changed these settings using the router’s default username and password will not work.

Once logged in to the panel, go to the section dedicated to the list of connected devices (its name varies depending on your provider and/or the router in use) and check if this includes any that are unknown to you. If so, immediately change the Wi-Fi password, so as to block it and lose access to the unauthorized device.

After that, you might decide to click on the name of the unknown device, go to the section dedicated to the MAC Address filter, activate it and specify one by one all the devices authorized to access the network by manually typing their MAC address (Media Access Control), a sort of identification “plate” made up of 12 digits, divided into pairs, which serves to uniquely identify each network card, be it Ethernet or wireless. Typing all these characters can be cumbersome, it’s true, but if you have detected an intruder in your Wi-Fi network, taking such a measure could be absolutely necessary.

5 tips to protect the internet from unwanted access

Once you understand how to monitor the network, it becomes essential to understand how to prevent unwanted access to your home Wi-Fi. Here are 5 precautions to take into account.

Place the router in a central location in your home

The location of the router has a direct impact on signal propagation. Placing it in a central area of ​​the home (in addition to improving the coverage of the Wi-Fi network in the home) reduces the dispersion of the signal towards the outside, limiting the area in which the signal is accessible to potential attackers. Radio waves, in fact, propagate in all directions and can overcome walls and obstacles, making the network visible even outside your home.

Use advanced security settings

Using advanced security settings is also essential to avoid Wi-Fi intrusions. This practically translates into changing the Wi-Fi name and password set “by default” by choosing a complex access key, which is long, not based on personal data and also composed of special characters (e.g. !, ?, &, etc.). It is also important to activate the firewall from the router settings and encryption. The firewall is a system that filters incoming and outgoing traffic, blocking suspicious connections. Wi-Fi encryption, on the other hand, protects transmitted data by making it readable only to authorized devices. The most recent protocol is WPA3, an evolution of the previous WPA2, and introduces more robust algorithms for protecting communications. If your router only supports WPA2, you may want to consider a hardware upgrade.

Create a “Guest” network

An additional measure is to create a separate network for guests. This way we isolate external devices from the main network, reducing the risk of any vulnerabilities propagating. This approach is particularly useful for IoT devices (Internet of Things), home automation ones so to speak, often less protected at a software level.

Use a secure VPN

Using a secure VPN (Virtual Private Network) adds an extra layer of privacy by masking your IP address and encrypting your traffic. Although its use is more relevant when connecting to unsecured networks, it can help strengthen overall security.

Disable remote access to the router

Finally, we also recommend deactivating remote access to the router, a function which, although useful in some contexts, can increase the attack surface. Also in this case, you can proceed with the modification by acting from the router settings panel.