Who's Connected to My Wi-Fi? How to Detect and Block Other Devices

Is your internet slowing down and your data usage running out suspiciously quickly? Someone else might be accessing your Wi-Fi. According to KasperskyOne in five routers in Russia has vulnerabilities that allow attackers to exploit someone else's network to download files, mine cryptocurrency, or even conduct cyberattacks. Meanwhile, 63% of users never check the list of connected devices.

In this article you will learn how detect other people's gadgets on your network—from simple methods via the router's web interface to advanced methods using specialized applications. We'll also tell you how block unauthorized connections and configure your router to prevent re-hacking. All instructions are adapted for popular router models: TP-Link, ASUS, Keenetic, MikroTik And Zyxel.

A word of warning: if you find unknown devices online, don't rush to blame your neighbors. Sometimes "foreign" gadgets turn out to be smart light bulbs, IP cameras or even old smartphones, which you've long forgotten. But if your suspicions are confirmed, our recommendations will help you regain control of your network.

1. Checking via the router's web interface: the most reliable method

Any router keeps a log of connected devices, and this is the first source worth checking. It can be accessed through web interface — the router's control panel. The login address is usually located on a sticker on the back of the device (e.g., 192.168.0.1 or 192.168.1.1).

Step-by-step instructions:

• 🔌 Connect to the router via cable or Wi-Fi (preferably from a device you know exactly).
• 🌐 Enter the router's IP address in the browser's address bar (for example, 192.168.1.1).
• 🔑 Enter your login and password (by default it is often admin/admin, but it’s better to check on the sticker).
• 📊 Find the section with connected devices. Depending on the model, it may be called:
  • TP-Link: DHCP → DHCP Clients or Wireless Mode → Wireless Mode Statistics
  • ASUS: Network Map → Clients
  • Keenetic: Devices → Device List
  • Zyxel: Network → Active Connections

The list will show all gadgets that are currently or have recently been online. Pay attention to:

• 📱 Device name (For example, iPhone-12-Pro or Samsung-Galaxy-S21). Unknown names like android-123456 or Unknown should be a warning sign.
• 🔗 MAC address — unique device identifier (example: 00:1A:2B:3C:4D:5E). It can be used for blocking.
• 📶 Connection type (Wi-Fi or cable). Outsiders often connect over the air.
• ⏱️ Connection timeIf the device is active at night while you are sleeping, this is suspicious.

Take a photo of your connected devices | Check your devices' MAC addresses (read below for instructions) | Disable the guest network if it's enabled | Change your Wi-Fi password to a more complex one.

⚠️ Attention: Some routers (eg. MikroTik) show in the list not only active ones, but also reserved IP addresses For devices that haven't been connected in a while. Don't block them without checking—they could be your devices in sleep mode.

2. How to find out the MAC addresses of your devices (to avoid blocking them)

Before blocking unknown gadgets, make sure they aren't yours. To do this, you need to know MAC addresses all your smartphones, laptops, tablets, and smart devices. Here's how to do it on different devices:

Compare the received addresses with those displayed in the router's web interface. If any MAC address in the router's list doesn't match any of yours, it's a problem. 100% foreign deviceWrite down his address for future blocking.

3. Special applications for network scanning

If your router's web interface seems complicated, you can use mobile apps that scan the network and display all connected devices in a convenient layout. Here are the top 5 proven utilities:

• 📱 Fing (iOS/Android) — the most popular app for port scanning and device manufacturer identification by MAC address. The free version displays up to 5 devices.
• 🛡️ NetCut (Android) - allows you to not only scan the network, but also turn off suspicious devices (requires root rights).
• 🔍 WiFi Guard (Android) — automatically notifies you of new devices on the network and keeps a connection history.
• 📊 IP Tools: Network Utilities (iOS/Android) - a comprehensive utility with ping, traceroute and network scanning functions.
• 🖥️ Advanced IP Scanner (Windows) - a free PC program that displays all IP and MAC addresses on a local network.

Example of working with Fing:

1. Download the app from App Store or Google Play.
2. Connect to your Wi-Fi network.
3. Click Scan - after 10-20 seconds you will see a list of devices indicating:
   • 📌 Titles (if the device broadcasts them).
   • 🔢 IP and MAC addresses.
   • 📡 Manufacturer (by the first MAC characters).
   • ⚡ Device type (smartphone, PC, IoT gadget).

The advantage of apps is that they often recognize device manufacturer by MAC address. For example, if you see a gadget with a MAC address starting with 3C:5A:B4, then this is the device Google (can be checked Here). This helps to distinguish Android-smartphone from iPhone or a smart speaker.

⚠️ Attention: Some applications (eg. NetCut) require root rights on Android to lock devices. Without them, they only work in scanning mode. On iOS, capabilities are limited due to policy Apple.

Via the router's web interface|Mobile app|Command line|Never tested-->

4. Checking via the command line (for advanced users)

If you prefer to work without graphical interfaces, you can scan the network using commands in terminal (Windows/macOS/Linux) This method is suitable for advanced users, as it requires basic knowledge of network protocols.

For Windows:

1. Open Command line (Win + R → cmd).
2. Enter the command to view active connections:

   arp -a

   You will see a table with the IP and MAC addresses of devices with which your computer has recently interacted.

3. To get a complete list of devices on the network, use:

   for /L %i in (1,1,254) do ping -n 1 192.168.1.%i | find "Answer"

   (replace 192.168.1 to your subnet, for example, 192.168.0).

For macOS/Linux:

1. Open Terminal.
2. Enter the command to scan the network:

   nmap -sn 192.168.1.0/24

   (install nmap through brew install nmap or sudo apt install nmap).

3. For detailed information on each IP:

   nmap -O 192.168.1.100

   (replace 100 to the last octet of IP).

These commands will show all active hosts on your network, including those that are not visible in the router's web interface (for example, devices in sleep mode or with DHCP disabled).

What to do if the arp -a command shows few devices?

Team arp -a displays only those devices your computer has interacted with recently. To see the full list, first ping all IPs in your subnet (as shown in the loop example). for), and then run it again arp -a.

5. How to Block a Foreign Device: 3 Reliable Methods

If you find an unknown device on your network, you need to block it. Here are three ways, from easiest to most reliable:

Method 1: Blocking by MAC address (filtering)

The most effective way is deny connection by MAC address through the router settings:

1. Go to the router's web interface (as in the first section).
2. Find the section Wireless Mode → MAC Filter (or Security → MAC Filter).
3. Add the MAC address of the foreign device to blacklist.
4. Save the settings and reboot the router.

Method 2: Change your Wi-Fi password

If MAC blocking does not help (for example, an attacker replaces the MAC), change your password from Wi-Fi:

• 🔑 Use a complex password of at least 12 characters with numbers, letters, and special characters (example: W7#k9P!2x$5L).
• 🔄 Change network name (SSID) - This will force all users to reconnect.
• 🔒 Enable encryption WPA3 (if supported) or WPA2-AES (don't use outdated WEP!).

Method 3: Disabling DHCP and Manually Binding IP

For advanced users: Disable automatic IP address distribution and manually assign IP addresses only to your devices:

1. In the router's web interface, find LAN → DHCP server.
2. Disable DHCP and install static IP pool.
3. In the section Address reservation Bind your devices' MAC addresses to specific IP addresses.

6. How to protect your router from re-hacking: 7 essential steps

Even after blocking unauthorized devices, your router may still be vulnerable. Follow these recommendations to minimize the risks:

• 🔐 Change the default password for the admin panel router (not admin/admin!). Use a password generator.
• 🔄 Update your router firmware to the latest version (section System → Software Update).
• 🚫 Disable WPS - this protocol is vulnerable to brute force attacks (located in Wireless Mode → WPS).
• 📡 Disable the guest network, if you don't use it (or set up a separate password for it).
• 🕶️ Hide SSID (network name) - this is not protection, but will reduce the number of accidental connections (Wireless Mode → Hide SSID).
• ⏱️ Set up a Wi-Fi schedule (for example, power outage at night) in Wireless Mode → Schedule.
• 🛡️ Enable the firewall and disable remote access to the router (System → Remote Control).

Additionally, you can use VPN on a router (if supported) or segment the network using VLAN, but this requires in-depth knowledge.

⚠️ Attention: Some internet service providers (eg. Rostelecom, Beeline) block access to router settings if it's rented. In this case, contact support and ask them to change the Wi-Fi password or update the firmware.

7. What to do if nothing helps: extreme measures

If foreign devices continue to appear on the network even after all the manipulations, it is possible:

• 🕵️‍♂️ Your router hacked and is controlled by an attacker (for example, through a backdoor in the firmware).
• 📡 Someone is using repeater or second device to boost your signal.
• 🏢 In an apartment building Wi-Fi channels overlap, and you see other people's devices due to a router error.

In such cases:

1. Reset your router to factory settings (button Reset on the back panel, hold for 10-15 seconds).
2. Check your router for viruses using antivirus software for network devices (for example, Bitdefender Box).
3. Buy a new router, if the current one is outdated (models older than 5 years often have unfixable vulnerabilities).
4. Contact your provider - perhaps the problem is on their side (for example, public IP address with a neighbor).

If you suspect that your traffic is being used for illegal activities (for example, DDoS attacks), save router logs (chapter System → Journal) and contact the police with a statement about unauthorized access (Article 272 of the Criminal Code of the Russian Federation).

FAQ: Frequently asked questions about unauthorized Wi-Fi connections

❓ Can my neighbor connect to my Wi-Fi if I hide the SSID?

Hiding the network name (SSID) doesn't protect against connections. An experienced user can connect manually if they know the network name and password. This is more of a precaution against accidental connections than against targeted hacking.

❓ Why do unknown devices with names like "Android-1234" appear in the device list?

These could be:

• 📱 Old smartphones that you haven't used for a long time, but they periodically connect to the network.
• 💡 Smart devices (lamps, sockets) that you forgot to set up.
• 🤖 Bots or vulnerability scanners that attempt to connect to open ports.

Check the MAC address of such a device - if it does not match any of yours, block it.

❓ How can I tell if a third-party device isn't just connected, but is stealing my data?

Signs of a dangerous connection:

• 🔍 In the router log (System → Journal) there are attempts to access the admin panel.
• 📥 Large amounts of data are downloading unexpectedly (check in Traffic statistics).
• 🔄 Your devices start to be redirected to strange websites (DNS spoofing).
• 💻 Unknown processes appear in the task manager (for example, svchost.exe with high network load).

In such cases, immediately Disconnect the router from the Internet and check its DNS server settings (the provider's servers should be specified or 8.8.8.8/1.1.1.1).

❓ Is it possible to track who is connected to my Wi-Fi?

Technically yes, but it requires deep knowledge:

• 📡 By MAC address You can determine the manufacturer of the device (first 6 characters).
• 🌍 By IP address (if it is external) - approximate location (but this will be your provider's IP, not the attacker's).
• 🕵️‍♂️ With the help of Wireshark You can analyze traffic and identify activity (for example, downloading torrents).

However, it is impossible to accurately identify a person without the involvement of law enforcement agencies.

❓ Why do unauthorized devices reappear after changing the password?

Possible reasons:

• 🔑 The password is too simple (for example, 12345678 or qwerty).
• 📡 The hacker uses WPS vulnerability or brute force to select a password.
• 🏠 Someone in your household shared the password with strangers (check your children or guests).
• 🔄 The router has been reset to factory settings (check the power and the button) Reset).

Solution: Change the password to a complex one, disable WPS, and update the router firmware.